From 3b87b5656d09521bf88619a4e51a71f9cfc6f1e3 Mon Sep 17 00:00:00 2001
From: Anthony Martin <38542602+anthony-c-martin@users.noreply.github.com>
Date: Sun, 17 Mar 2024 03:49:17 -0400
Subject: [PATCH] Initial spread implementation

---
 .../EvaluationTests.cs                        |  28 +--
 .../SpreadTests.cs                            | 173 ++++++++++++++++++
 .../baselines/Functions_LF/main.symbols.bicep |   2 +-
 .../InvalidLambdas_LF/main.diagnostics.bicep  |  14 +-
 .../InvalidLambdas_LF/main.symbols.bicep      |  54 +++---
 .../Lambdas_LF/main.diagnostics.bicep         |  82 +++++----
 .../baselines/Lambdas_LF/main.symbols.bicep   | 118 ++++++------
 .../Completions/symbolsPlusTypes.json         |  42 +++++
 .../Files/baselines/Variables_LF/main.bicep   |  12 ++
 .../Variables_LF/main.diagnostics.bicep       |  18 +-
 .../Variables_LF/main.formatted.bicep         |  12 ++
 .../baselines/Variables_LF/main.ir.bicep      |  44 ++++-
 .../Files/baselines/Variables_LF/main.json    |   7 +-
 .../Variables_LF/main.sourcemap.bicep         |  17 +-
 .../Variables_LF/main.symbolicnames.json      |   7 +-
 .../baselines/Variables_LF/main.symbols.bicep |  15 ++
 .../baselines/Variables_LF/main.syntax.bicep  |  88 ++++++++-
 .../baselines/Variables_LF/main.tokens.bicep  |  56 +++++-
 .../parameters.diagnostics.bicepparam         |   7 +-
 .../parameters.symbols.bicepparam             |   2 +-
 .../Diagnostics/ErrorBuilderTests.cs          |   7 +
 .../Diagnostics/DiagnosticBuilder.cs          |  10 +
 .../Emit/EmitLimitationCalculator.cs          |  36 ++++
 .../Intermediate/ExpressionBuilder.cs         |  82 ++++++++-
 src/Bicep.Core/Parsing/BaseParser.cs          |  28 ++-
 src/Bicep.Core/Parsing/Lexer.cs               |   6 +
 src/Bicep.Core/Parsing/TokenType.cs           |   1 +
 .../SyntaxLayouts.SyntaxVisitor.cs            |   2 +
 src/Bicep.Core/PrettyPrintV2/SyntaxLayouts.cs |   3 +
 .../Rewriters/DependsOnRemovalRewriter.cs     |   6 +-
 src/Bicep.Core/Syntax/AstVisitor.cs           |   5 +
 src/Bicep.Core/Syntax/CstVisitor.cs           |   6 +
 src/Bicep.Core/Syntax/ISyntaxVisitor.cs       |   2 +
 .../Syntax/ObjectSyntaxExtensions.cs          |   7 -
 .../Syntax/SpreadExpressionSyntax.cs          |  24 +++
 src/Bicep.Core/Syntax/SyntaxFactory.cs        |   1 +
 src/Bicep.Core/Syntax/SyntaxFacts.cs          |   1 +
 src/Bicep.Core/Syntax/SyntaxRewriteVisitor.cs |  14 ++
 src/Bicep.Core/Syntax/SyntaxVisitor.cs        |   2 +
 .../TypeSystem/TypeAssignmentVisitor.cs       | 158 ++++++++++++----
 .../Files/Working/lambdas/main.bicep          |  52 +++---
 41 files changed, 1009 insertions(+), 242 deletions(-)
 create mode 100644 src/Bicep.Core.IntegrationTests/SpreadTests.cs
 create mode 100644 src/Bicep.Core/Syntax/SpreadExpressionSyntax.cs

diff --git a/src/Bicep.Core.IntegrationTests/EvaluationTests.cs b/src/Bicep.Core.IntegrationTests/EvaluationTests.cs
index a0fdeccdbf6..77cc02fb04c 100644
--- a/src/Bicep.Core.IntegrationTests/EvaluationTests.cs
+++ b/src/Bicep.Core.IntegrationTests/EvaluationTests.cs
@@ -1211,45 +1211,45 @@ public void New_functions_are_evaluated_correctly()
         {
             var evaluated = TemplateEvaluator.Evaluate(template);
 
-            evaluated.Should().HaveValueAtPath("$.outputs['sayHello'].value", JToken.Parse("""
+            evaluated.Should().HaveJsonAtPath("$.outputs['sayHello'].value", """
 [
   "Hi Evie!",
   "Ahoy Casper!",
   "Hi Lady Lechuga!"
 ]
-"""));
+""");
 
-            evaluated.Should().HaveValueAtPath("$.outputs['evenEntries'].value", JToken.Parse("""
+            evaluated.Should().HaveJsonAtPath("$.outputs['evenEntries'].value", """
 [
   "a",
   "c"
 ]
-"""));
+""");
 
             evaluated.Should().HaveValueAtPath("$.outputs['concatIfEven'].value", "abcghi");
 
-            evaluated.Should().HaveValueAtPath("$.outputs['mapValuesTest'].value", JToken.Parse("""
+            evaluated.Should().HaveJsonAtPath("$.outputs['mapValuesTest'].value", """
 {
   "a": 246,
   "b": 912
 }
-"""));
+""");
 
-            evaluated.Should().HaveValueAtPath("$.outputs['objectKeysTest'].value", JToken.Parse("""
+            evaluated.Should().HaveJsonAtPath("$.outputs['objectKeysTest'].value", """
 [
   "a",
   "b"
 ]
-"""));
+""");
 
-            evaluated.Should().HaveValueAtPath("$.outputs['shallowMergeTest'].value", JToken.Parse("""
+            evaluated.Should().HaveJsonAtPath("$.outputs['shallowMergeTest'].value", """
 {
   "a": 123,
   "b": 456
 }
-"""));
+""");
 
-            evaluated.Should().HaveValueAtPath("$.outputs['groupByTest'].value", JToken.Parse("""
+            evaluated.Should().HaveJsonAtPath("$.outputs['groupByTest'].value", """
 {
   "a": [
     {
@@ -1268,9 +1268,9 @@ public void New_functions_are_evaluated_correctly()
     }
   ]
 }
-"""));
+""");
 
-            evaluated.Should().HaveValueAtPath("$.outputs['groupByWithValMapTest'].value", JToken.Parse("""
+            evaluated.Should().HaveJsonAtPath("$.outputs['groupByWithValMapTest'].value", """
 {
   "a": [
     123,
@@ -1280,7 +1280,7 @@ public void New_functions_are_evaluated_correctly()
     456
   ]
 }
-"""));
+""");
         }
     }
 }
diff --git a/src/Bicep.Core.IntegrationTests/SpreadTests.cs b/src/Bicep.Core.IntegrationTests/SpreadTests.cs
new file mode 100644
index 00000000000..dedfa581bdf
--- /dev/null
+++ b/src/Bicep.Core.IntegrationTests/SpreadTests.cs
@@ -0,0 +1,173 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+using Bicep.Core.UnitTests.Assertions;
+using Bicep.Core.UnitTests.Utils;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace Bicep.Core.IntegrationTests;
+
+[TestClass]
+public class SpreadTests
+{
+    [TestMethod]
+    public void Spread_operator_results_in_correct_codegen()
+    {
+        var result = CompilationHelper.Compile("""
+var other = {
+  bar: [1, ...[2, 3], 4]
+}
+
+output test object = {
+  foo: 'foo'
+  ...other
+  baz: 'baz'  
+}
+""");
+
+        result.ExcludingLinterDiagnostics().Should().NotHaveAnyDiagnostics();
+        result.Template.Should().HaveValueAtPath("$.variables['other']['bar']", "[flatten(createArray(createArray(1), createArray(2, 3), createArray(4)))]");
+        result.Template.Should().HaveValueAtPath("$.outputs['test'].value", "[shallowMerge(createArray(createObject('foo', 'foo'), variables('other'), createObject('baz', 'baz')))]");
+
+        var evaluated = TemplateEvaluator.Evaluate(result.Template);
+        evaluated.Should().HaveJsonAtPath("$.outputs['test'].value", """
+{
+  "foo": "foo",
+  "bar": [
+    1,
+    2,
+    3,
+    4
+  ],
+  "baz": "baz"
+}
+""");
+    }
+
+    [TestMethod]
+    public void Spread_operator_works_on_single_line()
+    {
+        var result = CompilationHelper.Compile("""
+param other object
+
+var test = { foo: 'foo', ...other, baz: 'baz' }
+""");
+
+        result.ExcludingLinterDiagnostics().Should().NotHaveAnyDiagnostics();
+    }
+
+    [TestMethod]
+    public void Array_spread_cannot_be_used_inside_object()
+    {
+        var result = CompilationHelper.Compile("""
+var other = ['bar']
+
+var test = {
+  foo: 'foo'
+  ...other
+  baz: 'baz'  
+}
+""");
+
+        result.ExcludingLinterDiagnostics().Should().ContainDiagnostic(
+            "BCP397", Diagnostics.DiagnosticLevel.Error, """The spread operator "..." can only be used in this context for an expression assignable to type "object".""");
+    }
+
+    [TestMethod]
+    public void Object_spread_cannot_be_used_inside_array()
+    {
+        var result = CompilationHelper.Compile("""
+var other = {
+  bar: 'bar'
+}
+
+var test = [
+  'foo'
+  ...other
+  'baz'  
+]
+""");
+
+        result.ExcludingLinterDiagnostics().Should().ContainDiagnostic(
+            "BCP397", Diagnostics.DiagnosticLevel.Error, """The spread operator "..." can only be used in this context for an expression assignable to type "array".""");
+    }
+
+    [TestMethod]
+    public void Spread_works_with_any()
+    {
+        var result = CompilationHelper.Compile("""
+var badObj = {
+  ...any(['foo'])
+}
+
+var badArray = [
+  ...any({ foo: 'foo' })
+]
+""");
+
+        result.ExcludingLinterDiagnostics().Should().NotHaveAnyDiagnostics();
+
+        // this will result in a runtime failure, but at least the codegen is correct.
+        result.Template.Should().HaveValueAtPath("$.variables['badObj']", "[shallowMerge(createArray(createArray('foo')))]");
+        result.Template.Should().HaveValueAtPath("$.variables['badArray']", "[flatten(createArray(createObject('foo', 'foo')))]");
+    }
+
+    [TestMethod]
+    public void Spread_is_blocked_in_resource_body()
+    {
+        var result = CompilationHelper.Compile("""
+var other = { location: 'westus' }
+
+resource foo 'Microsoft.Storage/storageAccounts@2023-01-01' = {
+  name: 'foo'
+  ...other
+}
+""");
+
+        result.ExcludingLinterDiagnostics().Should().ContainDiagnostic(
+            "BCP396", Diagnostics.DiagnosticLevel.Error, """The spread operator "..." is not permitted in this location.""");
+    }
+
+    [TestMethod]
+    public void Object_spread_edge_cases()
+    {
+        var result = CompilationHelper.Compile("""
+output test1 object = {
+  a: 0
+  ...{ a: 1, b: 0 }
+  c: 0
+}
+
+output test2 object = {
+  'ABC': 0
+  ...{ 'aBC': 1 }
+}
+
+output test3 object = {
+  foo: 'bar'
+  ...{ foo: null }
+}
+""");
+
+        result.ExcludingLinterDiagnostics().Should().NotHaveAnyDiagnostics();
+
+        var evaluated = TemplateEvaluator.Evaluate(result.Template);
+        evaluated.Should().HaveJsonAtPath("$.outputs['test1'].value", """
+{
+  "a": 1,
+  "b": 0,
+  "c": 0
+}
+""");
+        evaluated.Should().HaveJsonAtPath("$.outputs['test2'].value", """
+{
+  "ABC": 1
+}
+""");
+        evaluated.Should().HaveJsonAtPath("$.outputs['test3'].value", """
+{
+  "foo": null
+}
+""");
+    }
+}
\ No newline at end of file
diff --git a/src/Bicep.Core.Samples/Files/baselines/Functions_LF/main.symbols.bicep b/src/Bicep.Core.Samples/Files/baselines/Functions_LF/main.symbols.bicep
index a2d3ca065bb..ceed727cd87 100644
--- a/src/Bicep.Core.Samples/Files/baselines/Functions_LF/main.symbols.bicep
+++ b/src/Bicep.Core.Samples/Files/baselines/Functions_LF/main.symbols.bicep
@@ -12,7 +12,7 @@ func sayHello(name string) string => 'Hi ${name}!'
 //@[05:013) Function sayHello. Type: string => string. Declaration start char: 0, length: 50
 
 output hellos array = map(['Evie', 'Casper'], name => sayHello(name))
-//@[46:050) Local name. Type: any. Declaration start char: 46, length: 4
+//@[46:050) Local name. Type: 'Casper' | 'Evie'. Declaration start char: 46, length: 4
 //@[07:013) Output hellos. Type: array. Declaration start char: 0, length: 69
 
 func objReturnType(name string) object => {
diff --git a/src/Bicep.Core.Samples/Files/baselines/InvalidLambdas_LF/main.diagnostics.bicep b/src/Bicep.Core.Samples/Files/baselines/InvalidLambdas_LF/main.diagnostics.bicep
index e715f7fe241..9d9d56aca76 100644
--- a/src/Bicep.Core.Samples/Files/baselines/InvalidLambdas_LF/main.diagnostics.bicep
+++ b/src/Bicep.Core.Samples/Files/baselines/InvalidLambdas_LF/main.diagnostics.bicep
@@ -21,7 +21,7 @@ var map4 = map(range(0, 10), () => null)
 //@[29:39) [BCP070 (Error)] Argument of type "() => null" is not assignable to parameter of type "(any[, int]) => any". (CodeDescription: none) |() => null|
 var map5 = map(range(0, 10), (a, b, c) => a)
 //@[04:08) [no-unused-vars (Warning)] Variable "map5" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |map5|
-//@[29:43) [BCP070 (Error)] Argument of type "(any, int, any) => any" is not assignable to parameter of type "(any[, int]) => any". (CodeDescription: none) |(a, b, c) => a|
+//@[29:43) [BCP070 (Error)] Argument of type "(int, int, any) => int" is not assignable to parameter of type "(any[, int]) => any". (CodeDescription: none) |(a, b, c) => a|
 
 var filter1 = filter('abc')
 //@[04:11) [no-unused-vars (Warning)] Variable "filter1" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |filter1|
@@ -37,11 +37,13 @@ var filter4 = filter(range(0, 10), () => null)
 //@[35:45) [BCP070 (Error)] Argument of type "() => null" is not assignable to parameter of type "(any[, int]) => bool". (CodeDescription: none) |() => null|
 var filter5 = filter(range(0, 10), i => i)
 //@[04:11) [no-unused-vars (Warning)] Variable "filter5" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |filter5|
+//@[35:41) [BCP070 (Error)] Argument of type "int => int" is not assignable to parameter of type "(any[, int]) => bool". (CodeDescription: none) |i => i|
 var filter6 = filter([true, 'hello!'], i => i)
 //@[04:11) [no-unused-vars (Warning)] Variable "filter6" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |filter6|
+//@[39:45) [BCP070 (Error)] Argument of type "('hello!' | true) => ('hello!' | true)" is not assignable to parameter of type "(any[, int]) => bool". (CodeDescription: none) |i => i|
 var filter7 = filter(range(0, 10), (a, b, c) => true)
 //@[04:11) [no-unused-vars (Warning)] Variable "filter7" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |filter7|
-//@[35:52) [BCP070 (Error)] Argument of type "(any, int, any) => true" is not assignable to parameter of type "(any[, int]) => bool". (CodeDescription: none) |(a, b, c) => true|
+//@[35:52) [BCP070 (Error)] Argument of type "(int, int, any) => true" is not assignable to parameter of type "(any[, int]) => bool". (CodeDescription: none) |(a, b, c) => true|
 
 var sort1 = sort('abc')
 //@[04:09) [no-unused-vars (Warning)] Variable "sort1" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sort1|
@@ -57,9 +59,10 @@ var sort4 = sort(range(0, 10), () => null)
 //@[31:41) [BCP070 (Error)] Argument of type "() => null" is not assignable to parameter of type "(any, any) => bool". (CodeDescription: none) |() => null|
 var sort5 = sort(range(0, 10), i => i)
 //@[04:09) [no-unused-vars (Warning)] Variable "sort5" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sort5|
-//@[31:37) [BCP070 (Error)] Argument of type "any => any" is not assignable to parameter of type "(any, any) => bool". (CodeDescription: none) |i => i|
+//@[31:37) [BCP070 (Error)] Argument of type "int => int" is not assignable to parameter of type "(any, any) => bool". (CodeDescription: none) |i => i|
 var sort6 = sort(range(0, 10), (i, j) => i)
 //@[04:09) [no-unused-vars (Warning)] Variable "sort6" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sort6|
+//@[31:42) [BCP070 (Error)] Argument of type "(int, int) => int" is not assignable to parameter of type "(any, any) => bool". (CodeDescription: none) |(i, j) => i|
 
 var reduce1 = reduce('abc')
 //@[04:11) [no-unused-vars (Warning)] Variable "reduce1" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduce1|
@@ -75,10 +78,10 @@ var reduce4 = reduce(range(0, 10), 0, () => null)
 //@[38:48) [BCP070 (Error)] Argument of type "() => null" is not assignable to parameter of type "(any, any[, int]) => any". (CodeDescription: none) |() => null|
 var reduce5 = reduce(range(0, 10), 0, i => i)
 //@[04:11) [no-unused-vars (Warning)] Variable "reduce5" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduce5|
-//@[38:44) [BCP070 (Error)] Argument of type "any => any" is not assignable to parameter of type "(any, any[, int]) => any". (CodeDescription: none) |i => i|
+//@[38:44) [BCP070 (Error)] Argument of type "int => int" is not assignable to parameter of type "(any, any[, int]) => any". (CodeDescription: none) |i => i|
 var reduce6 = reduce(range(0, 10), 0, (a, b, c, d) => a)
 //@[04:11) [no-unused-vars (Warning)] Variable "reduce6" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduce6|
-//@[38:55) [BCP070 (Error)] Argument of type "(any, any, int, any) => any" is not assignable to parameter of type "(any, any[, int]) => any". (CodeDescription: none) |(a, b, c, d) => a|
+//@[38:55) [BCP070 (Error)] Argument of type "(int, int, int, any) => int" is not assignable to parameter of type "(any, any[, int]) => any". (CodeDescription: none) |(a, b, c, d) => a|
 
 var toObject1 = toObject('abc')
 //@[04:13) [no-unused-vars (Warning)] Variable "toObject1" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |toObject1|
@@ -94,6 +97,7 @@ var toObject4 = toObject(range(0, 10), () => null)
 //@[39:49) [BCP070 (Error)] Argument of type "() => null" is not assignable to parameter of type "any => string". (CodeDescription: none) |() => null|
 var toObject5 = toObject(range(0, 10), i => i)
 //@[04:13) [no-unused-vars (Warning)] Variable "toObject5" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |toObject5|
+//@[39:45) [BCP070 (Error)] Argument of type "int => int" is not assignable to parameter of type "any => string". (CodeDescription: none) |i => i|
 var toObject6 = toObject(range(0, 10), i => '${i}', 'def')
 //@[04:13) [no-unused-vars (Warning)] Variable "toObject6" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |toObject6|
 //@[52:57) [BCP070 (Error)] Argument of type "'def'" is not assignable to parameter of type "any => any". (CodeDescription: none) |'def'|
diff --git a/src/Bicep.Core.Samples/Files/baselines/InvalidLambdas_LF/main.symbols.bicep b/src/Bicep.Core.Samples/Files/baselines/InvalidLambdas_LF/main.symbols.bicep
index 770cfff8909..4bcd992abeb 100644
--- a/src/Bicep.Core.Samples/Files/baselines/InvalidLambdas_LF/main.symbols.bicep
+++ b/src/Bicep.Core.Samples/Files/baselines/InvalidLambdas_LF/main.symbols.bicep
@@ -15,7 +15,7 @@ var map3 = map(range(0, 10), 'def')
 var map4 = map(range(0, 10), () => null)
 //@[04:08) Variable map4. Type: error. Declaration start char: 0, length: 40
 var map5 = map(range(0, 10), (a, b, c) => a)
-//@[30:31) Local a. Type: any. Declaration start char: 30, length: 1
+//@[30:31) Local a. Type: int. Declaration start char: 30, length: 1
 //@[33:34) Local b. Type: int. Declaration start char: 33, length: 1
 //@[36:37) Local c. Type: any. Declaration start char: 36, length: 1
 //@[04:08) Variable map5. Type: error. Declaration start char: 0, length: 44
@@ -29,13 +29,13 @@ var filter3 = filter(range(0, 10), 'def')
 var filter4 = filter(range(0, 10), () => null)
 //@[04:11) Variable filter4. Type: error. Declaration start char: 0, length: 46
 var filter5 = filter(range(0, 10), i => i)
-//@[35:36) Local i. Type: any. Declaration start char: 35, length: 1
-//@[04:11) Variable filter5. Type: int[]. Declaration start char: 0, length: 42
+//@[35:36) Local i. Type: int. Declaration start char: 35, length: 1
+//@[04:11) Variable filter5. Type: error. Declaration start char: 0, length: 42
 var filter6 = filter([true, 'hello!'], i => i)
-//@[39:40) Local i. Type: any. Declaration start char: 39, length: 1
-//@[04:11) Variable filter6. Type: ('hello!' | true)[]. Declaration start char: 0, length: 46
+//@[39:40) Local i. Type: 'hello!' | true. Declaration start char: 39, length: 1
+//@[04:11) Variable filter6. Type: error. Declaration start char: 0, length: 46
 var filter7 = filter(range(0, 10), (a, b, c) => true)
-//@[36:37) Local a. Type: any. Declaration start char: 36, length: 1
+//@[36:37) Local a. Type: int. Declaration start char: 36, length: 1
 //@[39:40) Local b. Type: int. Declaration start char: 39, length: 1
 //@[42:43) Local c. Type: any. Declaration start char: 42, length: 1
 //@[04:11) Variable filter7. Type: error. Declaration start char: 0, length: 53
@@ -49,12 +49,12 @@ var sort3 = sort(range(0, 10), 'def')
 var sort4 = sort(range(0, 10), () => null)
 //@[04:09) Variable sort4. Type: error. Declaration start char: 0, length: 42
 var sort5 = sort(range(0, 10), i => i)
-//@[31:32) Local i. Type: any. Declaration start char: 31, length: 1
+//@[31:32) Local i. Type: int. Declaration start char: 31, length: 1
 //@[04:09) Variable sort5. Type: error. Declaration start char: 0, length: 38
 var sort6 = sort(range(0, 10), (i, j) => i)
-//@[32:33) Local i. Type: any. Declaration start char: 32, length: 1
-//@[35:36) Local j. Type: any. Declaration start char: 35, length: 1
-//@[04:09) Variable sort6. Type: int[]. Declaration start char: 0, length: 43
+//@[32:33) Local i. Type: int. Declaration start char: 32, length: 1
+//@[35:36) Local j. Type: int. Declaration start char: 35, length: 1
+//@[04:09) Variable sort6. Type: error. Declaration start char: 0, length: 43
 
 var reduce1 = reduce('abc')
 //@[04:11) Variable reduce1. Type: error. Declaration start char: 0, length: 27
@@ -65,11 +65,11 @@ var reduce3 = reduce(range(0, 10), 0, 'def')
 var reduce4 = reduce(range(0, 10), 0, () => null)
 //@[04:11) Variable reduce4. Type: error. Declaration start char: 0, length: 49
 var reduce5 = reduce(range(0, 10), 0, i => i)
-//@[38:39) Local i. Type: any. Declaration start char: 38, length: 1
+//@[38:39) Local i. Type: int. Declaration start char: 38, length: 1
 //@[04:11) Variable reduce5. Type: error. Declaration start char: 0, length: 45
 var reduce6 = reduce(range(0, 10), 0, (a, b, c, d) => a)
-//@[39:40) Local a. Type: any. Declaration start char: 39, length: 1
-//@[42:43) Local b. Type: any. Declaration start char: 42, length: 1
+//@[39:40) Local a. Type: int. Declaration start char: 39, length: 1
+//@[42:43) Local b. Type: int. Declaration start char: 42, length: 1
 //@[45:46) Local c. Type: int. Declaration start char: 45, length: 1
 //@[48:49) Local d. Type: any. Declaration start char: 48, length: 1
 //@[04:11) Variable reduce6. Type: error. Declaration start char: 0, length: 56
@@ -83,13 +83,13 @@ var toObject3 = toObject(range(0, 10), 'def')
 var toObject4 = toObject(range(0, 10), () => null)
 //@[04:13) Variable toObject4. Type: error. Declaration start char: 0, length: 50
 var toObject5 = toObject(range(0, 10), i => i)
-//@[39:40) Local i. Type: any. Declaration start char: 39, length: 1
-//@[04:13) Variable toObject5. Type: object. Declaration start char: 0, length: 46
+//@[39:40) Local i. Type: int. Declaration start char: 39, length: 1
+//@[04:13) Variable toObject5. Type: error. Declaration start char: 0, length: 46
 var toObject6 = toObject(range(0, 10), i => '${i}', 'def')
-//@[39:40) Local i. Type: any. Declaration start char: 39, length: 1
+//@[39:40) Local i. Type: int. Declaration start char: 39, length: 1
 //@[04:13) Variable toObject6. Type: error. Declaration start char: 0, length: 58
 var toObject7 = toObject(range(0, 10), i => '${i}', () => null)
-//@[39:40) Local i. Type: any. Declaration start char: 39, length: 1
+//@[39:40) Local i. Type: int. Declaration start char: 39, length: 1
 //@[04:13) Variable toObject7. Type: error. Declaration start char: 0, length: 63
 
 var ternary = map([123], true ? i => '${i}' : i => 'hello!')
@@ -136,20 +136,20 @@ resource stg 'Microsoft.Storage/storageAccounts@2021-09-01' = [for i in range(0,
 }]
 
 output stgKeys array = map(range(0, 2), i => stg[i].listKeys().keys[0].value)
-//@[40:41) Local i. Type: any. Declaration start char: 40, length: 1
+//@[40:41) Local i. Type: int. Declaration start char: 40, length: 1
 //@[07:14) Output stgKeys. Type: array. Declaration start char: 0, length: 77
 output stgKeys2 array = map(range(0, 2), j => stg[((j + 2) % 123)].listKeys().keys[0].value)
-//@[41:42) Local j. Type: any. Declaration start char: 41, length: 1
+//@[41:42) Local j. Type: int. Declaration start char: 41, length: 1
 //@[07:15) Output stgKeys2. Type: array. Declaration start char: 0, length: 92
 output stgKeys3 array = map(ids, id => listKeys(id, stg[0].apiVersion).keys[0].value)
 //@[33:35) Local id. Type: any. Declaration start char: 33, length: 2
 //@[07:15) Output stgKeys3. Type: array. Declaration start char: 0, length: 85
 output accessTiers array = map(range(0, 2), k => stg[k].properties.accessTier)
-//@[44:45) Local k. Type: any. Declaration start char: 44, length: 1
+//@[44:45) Local k. Type: int. Declaration start char: 44, length: 1
 //@[07:18) Output accessTiers. Type: array. Declaration start char: 0, length: 78
 output accessTiers2 array = map(range(0, 2), x => map(range(0, 2), y => stg[x / y].properties.accessTier))
-//@[67:68) Local y. Type: any. Declaration start char: 67, length: 1
-//@[45:46) Local x. Type: any. Declaration start char: 45, length: 1
+//@[67:68) Local y. Type: int. Declaration start char: 67, length: 1
+//@[45:46) Local x. Type: int. Declaration start char: 45, length: 1
 //@[07:19) Output accessTiers2. Type: array. Declaration start char: 0, length: 106
 output accessTiers3 array = map(ids, foo => reference('${foo}').accessTier)
 //@[37:40) Local foo. Type: any. Declaration start char: 37, length: 3
@@ -162,16 +162,16 @@ module modLoop './empty.bicep' = [for item in range(0, 5): {
 }]
 
 var modLoopNames = map(modLoop, i => i.name)
-//@[32:33) Local i. Type: any. Declaration start char: 32, length: 1
-//@[04:16) Variable modLoopNames. Type: array. Declaration start char: 0, length: 44
+//@[32:33) Local i. Type: module. Declaration start char: 32, length: 1
+//@[04:16) Variable modLoopNames. Type: string[]. Declaration start char: 0, length: 44
 output modOutputs array = map(range(0, 5), i => modLoop[i].outputs.foo)
-//@[43:44) Local i. Type: any. Declaration start char: 43, length: 1
+//@[43:44) Local i. Type: int. Declaration start char: 43, length: 1
 //@[07:17) Output modOutputs. Type: array. Declaration start char: 0, length: 71
 
 var onlyComma = map([0], (,) => 'foo')
 //@[04:13) Variable onlyComma. Type: error. Declaration start char: 0, length: 38
 var trailingCommas = map([0], (a,,) => 'foo')
-//@[31:32) Local a. Type: any. Declaration start char: 31, length: 1
+//@[31:32) Local a. Type: 0. Declaration start char: 31, length: 1
 //@[04:18) Variable trailingCommas. Type: 'foo'[]. Declaration start char: 0, length: 45
 var multiLineOnly = map([0], (
 //@[04:17) Variable multiLineOnly. Type: any. Declaration start char: 0, length: 51
@@ -182,7 +182,7 @@ var multiLineOnly = map([0], (
 var multiLineTrailingCommas = map([0], (
 //@[04:27) Variable multiLineTrailingCommas. Type: 'foo'[]. Declaration start char: 0, length: 60
   a,
-//@[02:03) Local a. Type: any. Declaration start char: 2, length: 1
+//@[02:03) Local a. Type: 0. Declaration start char: 2, length: 1
   ,) => 'foo')
 
 var lineBeforeComma = map([0], (
diff --git a/src/Bicep.Core.Samples/Files/baselines/Lambdas_LF/main.diagnostics.bicep b/src/Bicep.Core.Samples/Files/baselines/Lambdas_LF/main.diagnostics.bicep
index 2feac80d649..18e0ce6172c 100644
--- a/src/Bicep.Core.Samples/Files/baselines/Lambdas_LF/main.diagnostics.bicep
+++ b/src/Bicep.Core.Samples/Files/baselines/Lambdas_LF/main.diagnostics.bicep
@@ -10,54 +10,54 @@ func isEven(i int) bool => i % 2 == 0
 var numbers = range(0, 4)
 
 var sayHello = map(doggos, i => 'Hello ${i}!')
-//@[4:12) [no-unused-vars (Warning)] Variable "sayHello" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sayHello|
+//@[04:012) [no-unused-vars (Warning)] Variable "sayHello" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sayHello|
 // optional index parameter for map lambda
 var sayHello2 = map(doggos, (dog, i) => '${isEven(i) ? 'Hi' : 'Ahoy'} ${dog}!')
-//@[4:13) [no-unused-vars (Warning)] Variable "sayHello2" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sayHello2|
+//@[04:013) [no-unused-vars (Warning)] Variable "sayHello2" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sayHello2|
 
 var evenNumbers = filter(numbers, i => isEven(i))
-//@[4:15) [no-unused-vars (Warning)] Variable "evenNumbers" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |evenNumbers|
+//@[04:015) [no-unused-vars (Warning)] Variable "evenNumbers" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |evenNumbers|
 // optional index parameter for filter lambda
 var evenEntries = filter(['a', 'b', 'c', 'd'], (item, i) => isEven(i))
-//@[4:15) [no-unused-vars (Warning)] Variable "evenEntries" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |evenEntries|
+//@[04:015) [no-unused-vars (Warning)] Variable "evenEntries" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |evenEntries|
 
 var evenDoggosNestedLambdas = map(filter(numbers, i => contains(filter(numbers, j => 0 == j % 2), i)), x => doggos[x])
-//@[4:27) [no-unused-vars (Warning)] Variable "evenDoggosNestedLambdas" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |evenDoggosNestedLambdas|
+//@[04:027) [no-unused-vars (Warning)] Variable "evenDoggosNestedLambdas" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |evenDoggosNestedLambdas|
 
 var flattenedArrayOfArrays = flatten([[0, 1], [2, 3], [4, 5]])
-//@[4:26) [no-unused-vars (Warning)] Variable "flattenedArrayOfArrays" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |flattenedArrayOfArrays|
+//@[04:026) [no-unused-vars (Warning)] Variable "flattenedArrayOfArrays" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |flattenedArrayOfArrays|
 var flattenedEmptyArray = flatten([])
-//@[4:23) [no-unused-vars (Warning)] Variable "flattenedEmptyArray" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |flattenedEmptyArray|
+//@[04:023) [no-unused-vars (Warning)] Variable "flattenedEmptyArray" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |flattenedEmptyArray|
 
 var mapSayHi = map(['abc', 'def', 'ghi'], foo => 'Hi ${foo}!')
-//@[4:12) [no-unused-vars (Warning)] Variable "mapSayHi" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mapSayHi|
+//@[04:012) [no-unused-vars (Warning)] Variable "mapSayHi" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mapSayHi|
 var mapEmpty = map([], foo => 'Hi ${foo}!')
-//@[4:12) [no-unused-vars (Warning)] Variable "mapEmpty" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mapEmpty|
+//@[04:012) [no-unused-vars (Warning)] Variable "mapEmpty" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mapEmpty|
 var mapObject = map(range(0, length(doggos)), i => {
   i: i
   doggo: doggos[i]
   greeting: 'Ahoy, ${doggos[i]}!'
 })
 var mapArray = flatten(map(range(1, 3), i => [i * 2, (i * 2) + 1]))
-//@[4:12) [no-unused-vars (Warning)] Variable "mapArray" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mapArray|
+//@[04:012) [no-unused-vars (Warning)] Variable "mapArray" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mapArray|
 var mapMultiLineArray = flatten(map(range(1, 3), i => [
-//@[4:21) [no-unused-vars (Warning)] Variable "mapMultiLineArray" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mapMultiLineArray|
+//@[04:021) [no-unused-vars (Warning)] Variable "mapMultiLineArray" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mapMultiLineArray|
   i * 3
   (i * 3) + 1
   (i * 3) + 2
 ]))
 
 var filterEqualityCheck = filter(['abc', 'def', 'ghi'], foo => 'def' == foo)
-//@[4:23) [no-unused-vars (Warning)] Variable "filterEqualityCheck" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |filterEqualityCheck|
+//@[04:023) [no-unused-vars (Warning)] Variable "filterEqualityCheck" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |filterEqualityCheck|
 var filterEmpty = filter([], foo => 'def' == foo)
-//@[4:15) [no-unused-vars (Warning)] Variable "filterEmpty" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |filterEmpty|
+//@[04:015) [no-unused-vars (Warning)] Variable "filterEmpty" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |filterEmpty|
 
 var sortNumeric = sort([8, 3, 10, -13, 5], (x, y) => x < y)
-//@[4:15) [no-unused-vars (Warning)] Variable "sortNumeric" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sortNumeric|
+//@[04:015) [no-unused-vars (Warning)] Variable "sortNumeric" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sortNumeric|
 var sortAlpha = sort(['ghi', 'abc', 'def'], (x, y) => x < y)
-//@[4:13) [no-unused-vars (Warning)] Variable "sortAlpha" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sortAlpha|
+//@[04:013) [no-unused-vars (Warning)] Variable "sortAlpha" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sortAlpha|
 var sortAlphaReverse = sort(['ghi', 'abc', 'def'], (x, y) => x > y)
-//@[4:20) [no-unused-vars (Warning)] Variable "sortAlphaReverse" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sortAlphaReverse|
+//@[04:020) [no-unused-vars (Warning)] Variable "sortAlphaReverse" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sortAlphaReverse|
 var sortByObjectKey = sort([
   { key: 124, name: 'Second' }
   { key: 298, name: 'Third' }
@@ -65,26 +65,28 @@ var sortByObjectKey = sort([
   { key: 1232, name: 'Fourth' }
 ], (x, y) => int(x.key) < int(y.key))
 var sortEmpty = sort([], (x, y) => int(x) < int(y))
-//@[4:13) [no-unused-vars (Warning)] Variable "sortEmpty" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sortEmpty|
+//@[04:013) [no-unused-vars (Warning)] Variable "sortEmpty" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sortEmpty|
 
 var reduceStringConcat = reduce(['abc', 'def', 'ghi'], '', (cur, next) => concat(cur, next))
-//@[4:22) [no-unused-vars (Warning)] Variable "reduceStringConcat" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduceStringConcat|
+//@[04:022) [no-unused-vars (Warning)] Variable "reduceStringConcat" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduceStringConcat|
+//@[74:091) [prefer-interpolation (Warning)] Use string interpolation instead of the concat function. (CodeDescription: bicep core(https://aka.ms/bicep/linter/prefer-interpolation)) |concat(cur, next)|
 var reduceStringConcatEven = reduce(['abc', 'def', 'ghi'], '', (cur, next, i) => isEven(i) ? concat(cur, next) : cur)
-//@[4:26) [no-unused-vars (Warning)] Variable "reduceStringConcatEven" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduceStringConcatEven|
+//@[04:026) [no-unused-vars (Warning)] Variable "reduceStringConcatEven" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduceStringConcatEven|
+//@[93:110) [prefer-interpolation (Warning)] Use string interpolation instead of the concat function. (CodeDescription: bicep core(https://aka.ms/bicep/linter/prefer-interpolation)) |concat(cur, next)|
 var reduceFactorial = reduce(range(1, 5), 1, (cur, next) => cur * next)
-//@[4:19) [no-unused-vars (Warning)] Variable "reduceFactorial" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduceFactorial|
+//@[04:019) [no-unused-vars (Warning)] Variable "reduceFactorial" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduceFactorial|
 var reduceObjectUnion = reduce([
-//@[4:21) [no-unused-vars (Warning)] Variable "reduceObjectUnion" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduceObjectUnion|
+//@[04:021) [no-unused-vars (Warning)] Variable "reduceObjectUnion" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduceObjectUnion|
   { foo: 123 }
   { bar: 456 }
   { baz: 789 }
 ], {}, (cur, next) => union(cur, next))
 var reduceEmpty = reduce([], 0, (cur, next) => cur)
-//@[4:15) [no-unused-vars (Warning)] Variable "reduceEmpty" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduceEmpty|
+//@[04:015) [no-unused-vars (Warning)] Variable "reduceEmpty" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduceEmpty|
 
 var itemForLoop = [for item in range(0, 10): item]
 var filteredLoop = filter(itemForLoop, i => i > 5)
-//@[4:16) [no-unused-vars (Warning)] Variable "filteredLoop" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |filteredLoop|
+//@[04:016) [no-unused-vars (Warning)] Variable "filteredLoop" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |filteredLoop|
 
 output doggoGreetings array = [for item in mapObject: item.greeting]
 
@@ -92,7 +94,7 @@ resource storageAcc 'Microsoft.Storage/storageAccounts@2021-09-01' existing = {
   name: 'asdfsadf'
 }
 var mappedResProps = map(items(storageAcc.properties.secondaryEndpoints), item => item.value)
-//@[4:18) [no-unused-vars (Warning)] Variable "mappedResProps" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mappedResProps|
+//@[04:018) [no-unused-vars (Warning)] Variable "mappedResProps" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mappedResProps|
 
 module myMod './test.bicep' = {
   name: 'asdfsadf'
@@ -101,74 +103,76 @@ module myMod './test.bicep' = {
   }
 }
 var mappedModOutputProps = map(myMod.outputs.outputThis, doggo => '${doggo} says bork')
-//@[4:24) [no-unused-vars (Warning)] Variable "mappedModOutputProps" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mappedModOutputProps|
+//@[04:024) [no-unused-vars (Warning)] Variable "mappedModOutputProps" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mappedModOutputProps|
 
 var parentheses = map([123], (i => '${i}'))
-//@[4:15) [no-unused-vars (Warning)] Variable "parentheses" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |parentheses|
+//@[04:015) [no-unused-vars (Warning)] Variable "parentheses" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |parentheses|
 
 var objectMap = toObject([123, 456, 789], i => '${i / 100}')
-//@[4:13) [no-unused-vars (Warning)] Variable "objectMap" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectMap|
+//@[04:013) [no-unused-vars (Warning)] Variable "objectMap" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectMap|
 var objectMap2 = toObject(range(0, 10), i => '${i}', i => {
-//@[4:14) [no-unused-vars (Warning)] Variable "objectMap2" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectMap2|
+//@[04:014) [no-unused-vars (Warning)] Variable "objectMap2" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectMap2|
   isEven: (i % 2) == 0
   isGreaterThan4: (i > 4)
 })
 var objectMap3 = toObject(sortByObjectKey, x => x.name)
-//@[4:14) [no-unused-vars (Warning)] Variable "objectMap3" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectMap3|
+//@[04:014) [no-unused-vars (Warning)] Variable "objectMap3" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectMap3|
 var objectMap4 = toObject(sortByObjectKey, x =>
-//@[4:14) [no-unused-vars (Warning)] Variable "objectMap4" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectMap4|
+//@[04:014) [no-unused-vars (Warning)] Variable "objectMap4" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectMap4|
   
   x.name)
 var objectMap5 = toObject(sortByObjectKey, xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx => xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.name)
-//@[4:14) [no-unused-vars (Warning)] Variable "objectMap5" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectMap5|
+//@[04:014) [no-unused-vars (Warning)] Variable "objectMap5" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectMap5|
 var objectMap6 = toObject(range(0, 10), i => '${i}', i => // comment
-//@[4:14) [no-unused-vars (Warning)] Variable "objectMap6" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectMap6|
+//@[04:014) [no-unused-vars (Warning)] Variable "objectMap6" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectMap6|
 {
   isEven: (i % 2) == 0
   isGreaterThan4: (i > 4)
 })
 
 var multiLine = reduce(['abc', 'def', 'ghi'], '', (
-//@[4:13) [no-unused-vars (Warning)] Variable "multiLine" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |multiLine|
+//@[04:013) [no-unused-vars (Warning)] Variable "multiLine" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |multiLine|
   cur,
   next
 ) => concat(cur, next))
+//@[05:022) [prefer-interpolation (Warning)] Use string interpolation instead of the concat function. (CodeDescription: bicep core(https://aka.ms/bicep/linter/prefer-interpolation)) |concat(cur, next)|
 
 var multiLineWithComment = reduce(['abc', 'def', 'ghi'], '', (
-//@[4:24) [no-unused-vars (Warning)] Variable "multiLineWithComment" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |multiLineWithComment|
+//@[04:024) [no-unused-vars (Warning)] Variable "multiLineWithComment" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |multiLineWithComment|
   // comment
   cur,
   next
 ) => concat(cur, next))
+//@[05:022) [prefer-interpolation (Warning)] Use string interpolation instead of the concat function. (CodeDescription: bicep core(https://aka.ms/bicep/linter/prefer-interpolation)) |concat(cur, next)|
 
 var mapVals = mapValues({
-//@[4:11) [no-unused-vars (Warning)] Variable "mapVals" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mapVals|
+//@[04:011) [no-unused-vars (Warning)] Variable "mapVals" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mapVals|
   a: 123
   b: 456
 }, val => val * 2)
 
 var objectKeysTest = objectKeys({
-//@[4:18) [no-unused-vars (Warning)] Variable "objectKeysTest" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectKeysTest|
+//@[04:018) [no-unused-vars (Warning)] Variable "objectKeysTest" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectKeysTest|
   a: 123
   b: 456
 })
 
 var shallowMergeTest = shallowMerge([{
-//@[4:20) [no-unused-vars (Warning)] Variable "shallowMergeTest" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |shallowMergeTest|
+//@[04:020) [no-unused-vars (Warning)] Variable "shallowMergeTest" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |shallowMergeTest|
   a: 123
 }, {
   b: 456
 }])
 
 var groupByTest = groupBy([
-//@[4:15) [no-unused-vars (Warning)] Variable "groupByTest" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |groupByTest|
+//@[04:015) [no-unused-vars (Warning)] Variable "groupByTest" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |groupByTest|
   { type: 'a', value: 123 }
   { type: 'b', value: 456 }
   { type: 'a', value: 789 }
 ], arg => arg.type)
 
 var groupByWithValMapTest = groupBy([
-//@[4:25) [no-unused-vars (Warning)] Variable "groupByWithValMapTest" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |groupByWithValMapTest|
+//@[04:025) [no-unused-vars (Warning)] Variable "groupByWithValMapTest" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |groupByWithValMapTest|
   { type: 'a', value: 123 }
   { type: 'b', value: 456 }
   { type: 'a', value: 789 }
diff --git a/src/Bicep.Core.Samples/Files/baselines/Lambdas_LF/main.symbols.bicep b/src/Bicep.Core.Samples/Files/baselines/Lambdas_LF/main.symbols.bicep
index 9e3f19c40bf..88fa8efaaa5 100644
--- a/src/Bicep.Core.Samples/Files/baselines/Lambdas_LF/main.symbols.bicep
+++ b/src/Bicep.Core.Samples/Files/baselines/Lambdas_LF/main.symbols.bicep
@@ -14,27 +14,27 @@ var numbers = range(0, 4)
 //@[004:011) Variable numbers. Type: int[]. Declaration start char: 0, length: 25
 
 var sayHello = map(doggos, i => 'Hello ${i}!')
-//@[027:028) Local i. Type: any. Declaration start char: 27, length: 1
+//@[027:028) Local i. Type: 'Casper' | 'Evie' | 'Indy' | 'Kira'. Declaration start char: 27, length: 1
 //@[004:012) Variable sayHello. Type: string[]. Declaration start char: 0, length: 46
 // optional index parameter for map lambda
 var sayHello2 = map(doggos, (dog, i) => '${isEven(i) ? 'Hi' : 'Ahoy'} ${dog}!')
-//@[029:032) Local dog. Type: any. Declaration start char: 29, length: 3
+//@[029:032) Local dog. Type: 'Casper' | 'Evie' | 'Indy' | 'Kira'. Declaration start char: 29, length: 3
 //@[034:035) Local i. Type: int. Declaration start char: 34, length: 1
 //@[004:013) Variable sayHello2. Type: string[]. Declaration start char: 0, length: 79
 
 var evenNumbers = filter(numbers, i => isEven(i))
-//@[034:035) Local i. Type: any. Declaration start char: 34, length: 1
+//@[034:035) Local i. Type: int. Declaration start char: 34, length: 1
 //@[004:015) Variable evenNumbers. Type: int[]. Declaration start char: 0, length: 49
 // optional index parameter for filter lambda
 var evenEntries = filter(['a', 'b', 'c', 'd'], (item, i) => isEven(i))
-//@[048:052) Local item. Type: any. Declaration start char: 48, length: 4
+//@[048:052) Local item. Type: 'a' | 'b' | 'c' | 'd'. Declaration start char: 48, length: 4
 //@[054:055) Local i. Type: int. Declaration start char: 54, length: 1
 //@[004:015) Variable evenEntries. Type: ('a' | 'b' | 'c' | 'd')[]. Declaration start char: 0, length: 70
 
 var evenDoggosNestedLambdas = map(filter(numbers, i => contains(filter(numbers, j => 0 == j % 2), i)), x => doggos[x])
-//@[080:081) Local j. Type: any. Declaration start char: 80, length: 1
-//@[050:051) Local i. Type: any. Declaration start char: 50, length: 1
-//@[103:104) Local x. Type: any. Declaration start char: 103, length: 1
+//@[080:081) Local j. Type: int. Declaration start char: 80, length: 1
+//@[050:051) Local i. Type: int. Declaration start char: 50, length: 1
+//@[103:104) Local x. Type: int. Declaration start char: 103, length: 1
 //@[004:027) Variable evenDoggosNestedLambdas. Type: ('Casper' | 'Evie' | 'Indy' | 'Kira')[]. Declaration start char: 0, length: 118
 
 var flattenedArrayOfArrays = flatten([[0, 1], [2, 3], [4, 5]])
@@ -43,23 +43,23 @@ var flattenedEmptyArray = flatten([])
 //@[004:023) Variable flattenedEmptyArray. Type: <empty array>. Declaration start char: 0, length: 37
 
 var mapSayHi = map(['abc', 'def', 'ghi'], foo => 'Hi ${foo}!')
-//@[042:045) Local foo. Type: any. Declaration start char: 42, length: 3
+//@[042:045) Local foo. Type: 'abc' | 'def' | 'ghi'. Declaration start char: 42, length: 3
 //@[004:012) Variable mapSayHi. Type: string[]. Declaration start char: 0, length: 62
 var mapEmpty = map([], foo => 'Hi ${foo}!')
-//@[023:026) Local foo. Type: any. Declaration start char: 23, length: 3
+//@[023:026) Local foo. Type: never. Declaration start char: 23, length: 3
 //@[004:012) Variable mapEmpty. Type: string[]. Declaration start char: 0, length: 43
 var mapObject = map(range(0, length(doggos)), i => {
-//@[046:047) Local i. Type: any. Declaration start char: 46, length: 1
+//@[046:047) Local i. Type: int. Declaration start char: 46, length: 1
 //@[004:013) Variable mapObject. Type: object[]. Declaration start char: 0, length: 115
   i: i
   doggo: doggos[i]
   greeting: 'Ahoy, ${doggos[i]}!'
 })
 var mapArray = flatten(map(range(1, 3), i => [i * 2, (i * 2) + 1]))
-//@[040:041) Local i. Type: any. Declaration start char: 40, length: 1
+//@[040:041) Local i. Type: int. Declaration start char: 40, length: 1
 //@[004:012) Variable mapArray. Type: int[]. Declaration start char: 0, length: 67
 var mapMultiLineArray = flatten(map(range(1, 3), i => [
-//@[049:050) Local i. Type: any. Declaration start char: 49, length: 1
+//@[049:050) Local i. Type: int. Declaration start char: 49, length: 1
 //@[004:021) Variable mapMultiLineArray. Type: int[]. Declaration start char: 0, length: 95
   i * 3
   (i * 3) + 1
@@ -67,23 +67,23 @@ var mapMultiLineArray = flatten(map(range(1, 3), i => [
 ]))
 
 var filterEqualityCheck = filter(['abc', 'def', 'ghi'], foo => 'def' == foo)
-//@[056:059) Local foo. Type: any. Declaration start char: 56, length: 3
+//@[056:059) Local foo. Type: 'abc' | 'def' | 'ghi'. Declaration start char: 56, length: 3
 //@[004:023) Variable filterEqualityCheck. Type: ('abc' | 'def' | 'ghi')[]. Declaration start char: 0, length: 76
 var filterEmpty = filter([], foo => 'def' == foo)
-//@[029:032) Local foo. Type: any. Declaration start char: 29, length: 3
+//@[029:032) Local foo. Type: never. Declaration start char: 29, length: 3
 //@[004:015) Variable filterEmpty. Type: never[]. Declaration start char: 0, length: 49
 
 var sortNumeric = sort([8, 3, 10, -13, 5], (x, y) => x < y)
-//@[044:045) Local x. Type: any. Declaration start char: 44, length: 1
-//@[047:048) Local y. Type: any. Declaration start char: 47, length: 1
+//@[044:045) Local x. Type: -13 | 10 | 3 | 5 | 8. Declaration start char: 44, length: 1
+//@[047:048) Local y. Type: -13 | 10 | 3 | 5 | 8. Declaration start char: 47, length: 1
 //@[004:015) Variable sortNumeric. Type: (-13 | 10 | 3 | 5 | 8)[]. Declaration start char: 0, length: 59
 var sortAlpha = sort(['ghi', 'abc', 'def'], (x, y) => x < y)
-//@[045:046) Local x. Type: any. Declaration start char: 45, length: 1
-//@[048:049) Local y. Type: any. Declaration start char: 48, length: 1
+//@[045:046) Local x. Type: 'abc' | 'def' | 'ghi'. Declaration start char: 45, length: 1
+//@[048:049) Local y. Type: 'abc' | 'def' | 'ghi'. Declaration start char: 48, length: 1
 //@[004:013) Variable sortAlpha. Type: ('abc' | 'def' | 'ghi')[]. Declaration start char: 0, length: 60
 var sortAlphaReverse = sort(['ghi', 'abc', 'def'], (x, y) => x > y)
-//@[052:053) Local x. Type: any. Declaration start char: 52, length: 1
-//@[055:056) Local y. Type: any. Declaration start char: 55, length: 1
+//@[052:053) Local x. Type: 'abc' | 'def' | 'ghi'. Declaration start char: 52, length: 1
+//@[055:056) Local y. Type: 'abc' | 'def' | 'ghi'. Declaration start char: 55, length: 1
 //@[004:020) Variable sortAlphaReverse. Type: ('abc' | 'def' | 'ghi')[]. Declaration start char: 0, length: 67
 var sortByObjectKey = sort([
 //@[004:019) Variable sortByObjectKey. Type: (object | object | object | object)[]. Declaration start char: 0, length: 188
@@ -92,44 +92,44 @@ var sortByObjectKey = sort([
   { key: 24, name: 'First' }
   { key: 1232, name: 'Fourth' }
 ], (x, y) => int(x.key) < int(y.key))
-//@[004:005) Local x. Type: any. Declaration start char: 4, length: 1
-//@[007:008) Local y. Type: any. Declaration start char: 7, length: 1
+//@[004:005) Local x. Type: object | object | object | object. Declaration start char: 4, length: 1
+//@[007:008) Local y. Type: object | object | object | object. Declaration start char: 7, length: 1
 var sortEmpty = sort([], (x, y) => int(x) < int(y))
-//@[026:027) Local x. Type: any. Declaration start char: 26, length: 1
-//@[029:030) Local y. Type: any. Declaration start char: 29, length: 1
+//@[026:027) Local x. Type: never. Declaration start char: 26, length: 1
+//@[029:030) Local y. Type: never. Declaration start char: 29, length: 1
 //@[004:013) Variable sortEmpty. Type: never[]. Declaration start char: 0, length: 51
 
 var reduceStringConcat = reduce(['abc', 'def', 'ghi'], '', (cur, next) => concat(cur, next))
-//@[060:063) Local cur. Type: any. Declaration start char: 60, length: 3
-//@[065:069) Local next. Type: any. Declaration start char: 65, length: 4
-//@[004:022) Variable reduceStringConcat. Type: any. Declaration start char: 0, length: 92
+//@[060:063) Local cur. Type: 'abc' | 'def' | 'ghi'. Declaration start char: 60, length: 3
+//@[065:069) Local next. Type: 'abc' | 'def' | 'ghi'. Declaration start char: 65, length: 4
+//@[004:022) Variable reduceStringConcat. Type: string. Declaration start char: 0, length: 92
 var reduceStringConcatEven = reduce(['abc', 'def', 'ghi'], '', (cur, next, i) => isEven(i) ? concat(cur, next) : cur)
-//@[064:067) Local cur. Type: any. Declaration start char: 64, length: 3
-//@[069:073) Local next. Type: any. Declaration start char: 69, length: 4
+//@[064:067) Local cur. Type: 'abc' | 'def' | 'ghi'. Declaration start char: 64, length: 3
+//@[069:073) Local next. Type: 'abc' | 'def' | 'ghi'. Declaration start char: 69, length: 4
 //@[075:076) Local i. Type: int. Declaration start char: 75, length: 1
-//@[004:026) Variable reduceStringConcatEven. Type: any. Declaration start char: 0, length: 117
+//@[004:026) Variable reduceStringConcatEven. Type: 'abc' | 'def' | 'ghi' | string. Declaration start char: 0, length: 117
 var reduceFactorial = reduce(range(1, 5), 1, (cur, next) => cur * next)
-//@[046:049) Local cur. Type: any. Declaration start char: 46, length: 3
-//@[051:055) Local next. Type: any. Declaration start char: 51, length: 4
+//@[046:049) Local cur. Type: int. Declaration start char: 46, length: 3
+//@[051:055) Local next. Type: int. Declaration start char: 51, length: 4
 //@[004:019) Variable reduceFactorial. Type: int. Declaration start char: 0, length: 71
 var reduceObjectUnion = reduce([
-//@[004:021) Variable reduceObjectUnion. Type: any. Declaration start char: 0, length: 117
+//@[004:021) Variable reduceObjectUnion. Type: object. Declaration start char: 0, length: 117
   { foo: 123 }
   { bar: 456 }
   { baz: 789 }
 ], {}, (cur, next) => union(cur, next))
-//@[008:011) Local cur. Type: any. Declaration start char: 8, length: 3
-//@[013:017) Local next. Type: any. Declaration start char: 13, length: 4
+//@[008:011) Local cur. Type: object | object | object. Declaration start char: 8, length: 3
+//@[013:017) Local next. Type: object | object | object. Declaration start char: 13, length: 4
 var reduceEmpty = reduce([], 0, (cur, next) => cur)
-//@[033:036) Local cur. Type: any. Declaration start char: 33, length: 3
-//@[038:042) Local next. Type: any. Declaration start char: 38, length: 4
-//@[004:015) Variable reduceEmpty. Type: any. Declaration start char: 0, length: 51
+//@[033:036) Local cur. Type: never. Declaration start char: 33, length: 3
+//@[038:042) Local next. Type: never. Declaration start char: 38, length: 4
+//@[004:015) Variable reduceEmpty. Type: never. Declaration start char: 0, length: 51
 
 var itemForLoop = [for item in range(0, 10): item]
 //@[023:027) Local item. Type: int. Declaration start char: 23, length: 4
 //@[004:015) Variable itemForLoop. Type: int[]. Declaration start char: 0, length: 50
 var filteredLoop = filter(itemForLoop, i => i > 5)
-//@[039:040) Local i. Type: any. Declaration start char: 39, length: 1
+//@[039:040) Local i. Type: int. Declaration start char: 39, length: 1
 //@[004:016) Variable filteredLoop. Type: int[]. Declaration start char: 0, length: 50
 
 output doggoGreetings array = [for item in mapObject: item.greeting]
@@ -141,7 +141,7 @@ resource storageAcc 'Microsoft.Storage/storageAccounts@2021-09-01' existing = {
   name: 'asdfsadf'
 }
 var mappedResProps = map(items(storageAcc.properties.secondaryEndpoints), item => item.value)
-//@[074:078) Local item. Type: any. Declaration start char: 74, length: 4
+//@[074:078) Local item. Type: object. Declaration start char: 74, length: 4
 //@[004:018) Variable mappedResProps. Type: array. Declaration start char: 0, length: 93
 
 module myMod './test.bicep' = {
@@ -149,7 +149,7 @@ module myMod './test.bicep' = {
   name: 'asdfsadf'
   params: {
     outputThis: map(mapObject, obj => obj.doggo)
-//@[031:034) Local obj. Type: any. Declaration start char: 31, length: 3
+//@[031:034) Local obj. Type: object. Declaration start char: 31, length: 3
   }
 }
 var mappedModOutputProps = map(myMod.outputs.outputThis, doggo => '${doggo} says bork')
@@ -161,29 +161,29 @@ var parentheses = map([123], (i => '${i}'))
 //@[004:015) Variable parentheses. Type: string[]. Declaration start char: 0, length: 43
 
 var objectMap = toObject([123, 456, 789], i => '${i / 100}')
-//@[042:043) Local i. Type: any. Declaration start char: 42, length: 1
+//@[042:043) Local i. Type: 123 | 456 | 789. Declaration start char: 42, length: 1
 //@[004:013) Variable objectMap. Type: object. Declaration start char: 0, length: 60
 var objectMap2 = toObject(range(0, 10), i => '${i}', i => {
-//@[040:041) Local i. Type: any. Declaration start char: 40, length: 1
-//@[053:054) Local i. Type: any. Declaration start char: 53, length: 1
+//@[040:041) Local i. Type: int. Declaration start char: 40, length: 1
+//@[053:054) Local i. Type: int. Declaration start char: 53, length: 1
 //@[004:014) Variable objectMap2. Type: object. Declaration start char: 0, length: 111
   isEven: (i % 2) == 0
   isGreaterThan4: (i > 4)
 })
 var objectMap3 = toObject(sortByObjectKey, x => x.name)
-//@[043:044) Local x. Type: any. Declaration start char: 43, length: 1
+//@[043:044) Local x. Type: object | object | object | object. Declaration start char: 43, length: 1
 //@[004:014) Variable objectMap3. Type: object. Declaration start char: 0, length: 55
 var objectMap4 = toObject(sortByObjectKey, x =>
-//@[043:044) Local x. Type: any. Declaration start char: 43, length: 1
+//@[043:044) Local x. Type: object | object | object | object. Declaration start char: 43, length: 1
 //@[004:014) Variable objectMap4. Type: object. Declaration start char: 0, length: 60
   
   x.name)
 var objectMap5 = toObject(sortByObjectKey, xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx => xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.name)
-//@[043:081) Local xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx. Type: any. Declaration start char: 43, length: 38
+//@[043:081) Local xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx. Type: object | object | object | object. Declaration start char: 43, length: 38
 //@[004:014) Variable objectMap5. Type: object. Declaration start char: 0, length: 129
 var objectMap6 = toObject(range(0, 10), i => '${i}', i => // comment
-//@[040:041) Local i. Type: any. Declaration start char: 40, length: 1
-//@[053:054) Local i. Type: any. Declaration start char: 53, length: 1
+//@[040:041) Local i. Type: int. Declaration start char: 40, length: 1
+//@[053:054) Local i. Type: int. Declaration start char: 53, length: 1
 //@[004:014) Variable objectMap6. Type: object. Declaration start char: 0, length: 122
 {
   isEven: (i % 2) == 0
@@ -191,20 +191,20 @@ var objectMap6 = toObject(range(0, 10), i => '${i}', i => // comment
 })
 
 var multiLine = reduce(['abc', 'def', 'ghi'], '', (
-//@[004:013) Variable multiLine. Type: any. Declaration start char: 0, length: 89
+//@[004:013) Variable multiLine. Type: string. Declaration start char: 0, length: 89
   cur,
-//@[002:005) Local cur. Type: any. Declaration start char: 2, length: 3
+//@[002:005) Local cur. Type: 'abc' | 'def' | 'ghi'. Declaration start char: 2, length: 3
   next
-//@[002:006) Local next. Type: any. Declaration start char: 2, length: 4
+//@[002:006) Local next. Type: 'abc' | 'def' | 'ghi'. Declaration start char: 2, length: 4
 ) => concat(cur, next))
 
 var multiLineWithComment = reduce(['abc', 'def', 'ghi'], '', (
-//@[004:024) Variable multiLineWithComment. Type: any. Declaration start char: 0, length: 113
+//@[004:024) Variable multiLineWithComment. Type: string. Declaration start char: 0, length: 113
   // comment
   cur,
-//@[002:005) Local cur. Type: any. Declaration start char: 2, length: 3
+//@[002:005) Local cur. Type: 'abc' | 'def' | 'ghi'. Declaration start char: 2, length: 3
   next
-//@[002:006) Local next. Type: any. Declaration start char: 2, length: 4
+//@[002:006) Local next. Type: 'abc' | 'def' | 'ghi'. Declaration start char: 2, length: 4
 ) => concat(cur, next))
 
 var mapVals = mapValues({
@@ -212,7 +212,7 @@ var mapVals = mapValues({
   a: 123
   b: 456
 }, val => val * 2)
-//@[003:006) Local val. Type: any. Declaration start char: 3, length: 3
+//@[003:006) Local val. Type: 123 | 456. Declaration start char: 3, length: 3
 
 var objectKeysTest = objectKeys({
 //@[004:018) Variable objectKeysTest. Type: ('a' | 'b')[]. Declaration start char: 0, length: 54
@@ -233,7 +233,7 @@ var groupByTest = groupBy([
   { type: 'b', value: 456 }
   { type: 'a', value: 789 }
 ], arg => arg.type)
-//@[003:006) Local arg. Type: any. Declaration start char: 3, length: 3
+//@[003:006) Local arg. Type: object | object | object. Declaration start char: 3, length: 3
 
 var groupByWithValMapTest = groupBy([
 //@[004:025) Variable groupByWithValMapTest. Type: object. Declaration start char: 0, length: 159
@@ -241,6 +241,6 @@ var groupByWithValMapTest = groupBy([
   { type: 'b', value: 456 }
   { type: 'a', value: 789 }
 ], arg => arg.type, arg => arg.value)
-//@[003:006) Local arg. Type: any. Declaration start char: 3, length: 3
-//@[020:023) Local arg. Type: any. Declaration start char: 20, length: 3
+//@[003:006) Local arg. Type: object | object | object. Declaration start char: 3, length: 3
+//@[020:023) Local arg. Type: object | object | object. Declaration start char: 20, length: 3
 
diff --git a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/Completions/symbolsPlusTypes.json b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/Completions/symbolsPlusTypes.json
index 20572ae7f6a..aef989af71e 100644
--- a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/Completions/symbolsPlusTypes.json
+++ b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/Completions/symbolsPlusTypes.json
@@ -265,6 +265,20 @@
       "newText": "arrayOfStringsViaLoop"
     }
   },
+  {
+    "label": "arraySpread",
+    "kind": "variable",
+    "detail": "arraySpread",
+    "deprecated": false,
+    "preselect": false,
+    "sortText": "2_arraySpread",
+    "insertTextFormat": "plainText",
+    "insertTextMode": "adjustIndentation",
+    "textEdit": {
+      "range": {},
+      "newText": "arraySpread"
+    }
+  },
   {
     "label": "az",
     "kind": "folder",
@@ -2849,6 +2863,20 @@
       "command": "editor.action.triggerParameterHints"
     }
   },
+  {
+    "label": "spread",
+    "kind": "variable",
+    "detail": "spread",
+    "deprecated": false,
+    "preselect": false,
+    "sortText": "2_spread",
+    "insertTextFormat": "plainText",
+    "insertTextMode": "adjustIndentation",
+    "textEdit": {
+      "range": {},
+      "newText": "spread"
+    }
+  },
   {
     "label": "startsWith",
     "kind": "function",
@@ -3087,6 +3115,20 @@
       "command": "editor.action.triggerParameterHints"
     }
   },
+  {
+    "label": "test",
+    "kind": "variable",
+    "detail": "test",
+    "deprecated": false,
+    "preselect": false,
+    "sortText": "2_test",
+    "insertTextFormat": "plainText",
+    "insertTextMode": "adjustIndentation",
+    "textEdit": {
+      "range": {},
+      "newText": "test"
+    }
+  },
   {
     "label": "toLower",
     "kind": "function",
diff --git a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.bicep b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.bicep
index f99c11841a0..e787a698ca7 100644
--- a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.bicep
+++ b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.bicep
@@ -358,3 +358,15 @@ var joinedString = join(['I', 'love', 'Bicep!'], ' ')
 
 var prefix = take('food', 3)
 var isPrefixed = startsWith('food', 'foo')
+
+var spread = {
+  foo: 'abc'
+  ...issue1332
+}
+
+var test = {
+  ...spread
+  bar: 'def'
+}
+
+var arraySpread = [...arrayOfBooleans, ...arrayOfHardCodedNumbers, ...arrayOfHardCodedStrings]
diff --git a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.diagnostics.bicep b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.diagnostics.bicep
index 6c81d44d25f..7b010b2874f 100644
--- a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.diagnostics.bicep
+++ b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.diagnostics.bicep
@@ -296,7 +296,6 @@ var scopesWithArmRepresentation = {
 // Issue #1332
 var issue1332_propname = 'ptest'
 var issue1332 = true ? {
-//@[04:13) [no-unused-vars (Warning)] Variable "issue1332" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |issue1332|
     prop1: {
         '${issue1332_propname}': {}
     }
@@ -364,13 +363,10 @@ var arrayOfArraysViaLoop = [for (name, i) in loopInput: [
   'prefix-${i}-${name}-suffix'
 ]]
 var arrayOfBooleans = [for (name, i) in loopInput: i % 2 == 0]
-//@[04:19) [no-unused-vars (Warning)] Variable "arrayOfBooleans" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |arrayOfBooleans|
 var arrayOfHardCodedNumbers = [for i in range(0,10): 3]
-//@[04:27) [no-unused-vars (Warning)] Variable "arrayOfHardCodedNumbers" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |arrayOfHardCodedNumbers|
 var arrayOfHardCodedBools = [for i in range(0,10): false]
 //@[04:25) [no-unused-vars (Warning)] Variable "arrayOfHardCodedBools" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |arrayOfHardCodedBools|
 var arrayOfHardCodedStrings = [for i in range(0,3): 'hi']
-//@[04:27) [no-unused-vars (Warning)] Variable "arrayOfHardCodedStrings" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |arrayOfHardCodedStrings|
 var arrayOfNonRuntimeFunctionCalls = [for i in range(0,3): concat('hi', i)]
 //@[04:34) [no-unused-vars (Warning)] Variable "arrayOfNonRuntimeFunctionCalls" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |arrayOfNonRuntimeFunctionCalls|
 //@[59:74) [prefer-interpolation (Warning)] Use string interpolation instead of the concat function. (CodeDescription: bicep core(https://aka.ms/bicep/linter/prefer-interpolation)) |concat('hi', i)|
@@ -453,3 +449,17 @@ var prefix = take('food', 3)
 var isPrefixed = startsWith('food', 'foo')
 //@[04:14) [no-unused-vars (Warning)] Variable "isPrefixed" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |isPrefixed|
 
+var spread = {
+  foo: 'abc'
+  ...issue1332
+}
+
+var test = {
+//@[04:08) [no-unused-vars (Warning)] Variable "test" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |test|
+  ...spread
+  bar: 'def'
+}
+
+var arraySpread = [...arrayOfBooleans, ...arrayOfHardCodedNumbers, ...arrayOfHardCodedStrings]
+//@[04:15) [no-unused-vars (Warning)] Variable "arraySpread" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |arraySpread|
+
diff --git a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.formatted.bicep b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.formatted.bicep
index 2582d3f9d8d..71fabbbed2d 100644
--- a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.formatted.bicep
+++ b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.formatted.bicep
@@ -372,3 +372,15 @@ var joinedString = join(['I', 'love', 'Bicep!'], ' ')
 
 var prefix = take('food', 3)
 var isPrefixed = startsWith('food', 'foo')
+
+var spread = {
+  foo: 'abc'
+  ...issue1332
+}
+
+var test = {
+  ...spread
+  bar: 'def'
+}
+
+var arraySpread = [...arrayOfBooleans, ...arrayOfHardCodedNumbers, ...arrayOfHardCodedStrings]
diff --git a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.ir.bicep b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.ir.bicep
index e070de35b03..3aa8b09c29a 100644
--- a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.ir.bicep
+++ b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.ir.bicep
@@ -1,5 +1,5 @@
 
-//@[000:7923) ProgramExpression
+//@[000:8106) ProgramExpression
 // int
 @sys.description('an int variable')
 //@[000:0050) ├─DeclaredVariableExpression { Name = myInt }
@@ -1079,8 +1079,42 @@ var prefix = take('food', 3)
 //@[018:0024) |   ├─StringLiteralExpression { Value = food }
 //@[026:0027) |   └─IntegerLiteralExpression { Value = 3 }
 var isPrefixed = startsWith('food', 'foo')
-//@[000:0042) └─DeclaredVariableExpression { Name = isPrefixed }
-//@[017:0042)   └─FunctionCallExpression { Name = startsWith }
-//@[028:0034)     ├─StringLiteralExpression { Value = food }
-//@[036:0041)     └─StringLiteralExpression { Value = foo }
+//@[000:0042) ├─DeclaredVariableExpression { Name = isPrefixed }
+//@[017:0042) | └─FunctionCallExpression { Name = startsWith }
+//@[028:0034) |   ├─StringLiteralExpression { Value = food }
+//@[036:0041) |   └─StringLiteralExpression { Value = foo }
+
+var spread = {
+//@[000:0044) ├─DeclaredVariableExpression { Name = spread }
+//@[013:0044) | └─FunctionCallExpression { Name = shallowMerge }
+//@[013:0044) |   └─ArrayExpression
+//@[013:0044) |     ├─ObjectExpression
+  foo: 'abc'
+//@[002:0012) |     | └─ObjectPropertyExpression
+//@[002:0005) |     |   ├─StringLiteralExpression { Value = foo }
+//@[007:0012) |     |   └─StringLiteralExpression { Value = abc }
+  ...issue1332
+//@[005:0014) |     └─VariableReferenceExpression { Variable = issue1332 }
+}
+
+var test = {
+//@[000:0039) ├─DeclaredVariableExpression { Name = test }
+//@[011:0039) | └─FunctionCallExpression { Name = shallowMerge }
+//@[011:0039) |   └─ArrayExpression
+//@[011:0039) |     └─ObjectExpression
+  ...spread
+//@[005:0011) |     ├─VariableReferenceExpression { Variable = spread }
+  bar: 'def'
+//@[002:0012) |       └─ObjectPropertyExpression
+//@[002:0005) |         ├─StringLiteralExpression { Value = bar }
+//@[007:0012) |         └─StringLiteralExpression { Value = def }
+}
+
+var arraySpread = [...arrayOfBooleans, ...arrayOfHardCodedNumbers, ...arrayOfHardCodedStrings]
+//@[000:0094) └─DeclaredVariableExpression { Name = arraySpread }
+//@[018:0094)   └─FunctionCallExpression { Name = flatten }
+//@[018:0094)     └─ArrayExpression
+//@[022:0037)       ├─VariableReferenceExpression { Variable = arrayOfBooleans }
+//@[042:0065)       ├─VariableReferenceExpression { Variable = arrayOfHardCodedNumbers }
+//@[070:0093)       └─VariableReferenceExpression { Variable = arrayOfHardCodedStrings }
 
diff --git a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.json b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.json
index 97269da8f48..5bb8d02a380 100644
--- a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.json
+++ b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.json
@@ -5,7 +5,7 @@
     "_generator": {
       "name": "bicep",
       "version": "dev",
-      "templateHash": "15138089025540421016"
+      "templateHash": "3772439174458986220"
     }
   },
   "parameters": {
@@ -285,7 +285,10 @@
     },
     "joinedString": "[join(createArray('I', 'love', 'Bicep!'), ' ')]",
     "prefix": "[take('food', 3)]",
-    "isPrefixed": "[startsWith('food', 'foo')]"
+    "isPrefixed": "[startsWith('food', 'foo')]",
+    "spread": "[shallowMerge(createArray(createObject('foo', 'abc'), variables('issue1332')))]",
+    "test": "[shallowMerge(createArray(variables('spread'), createObject('bar', 'def')))]",
+    "arraySpread": "[flatten(createArray(variables('arrayOfBooleans'), variables('arrayOfHardCodedNumbers'), variables('arrayOfHardCodedStrings')))]"
   },
   "resources": []
 }
\ No newline at end of file
diff --git a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.sourcemap.bicep b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.sourcemap.bicep
index 0a1b824950e..219cd697791 100644
--- a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.sourcemap.bicep
+++ b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.sourcemap.bicep
@@ -630,5 +630,20 @@ var joinedString = join(['I', 'love', 'Bicep!'], ' ')
 var prefix = take('food', 3)
 //@    "prefix": "[take('food', 3)]",
 var isPrefixed = startsWith('food', 'foo')
-//@    "isPrefixed": "[startsWith('food', 'foo')]"
+//@    "isPrefixed": "[startsWith('food', 'foo')]",
+
+var spread = {
+//@    "spread": "[shallowMerge(createArray(createObject('foo', 'abc'), variables('issue1332')))]",
+  foo: 'abc'
+  ...issue1332
+}
+
+var test = {
+//@    "test": "[shallowMerge(createArray(variables('spread'), createObject('bar', 'def')))]",
+  ...spread
+  bar: 'def'
+}
+
+var arraySpread = [...arrayOfBooleans, ...arrayOfHardCodedNumbers, ...arrayOfHardCodedStrings]
+//@    "arraySpread": "[flatten(createArray(variables('arrayOfBooleans'), variables('arrayOfHardCodedNumbers'), variables('arrayOfHardCodedStrings')))]"
 
diff --git a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.symbolicnames.json b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.symbolicnames.json
index 35c88874eaa..da71d175ea3 100644
--- a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.symbolicnames.json
+++ b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.symbolicnames.json
@@ -6,7 +6,7 @@
     "_generator": {
       "name": "bicep",
       "version": "dev",
-      "templateHash": "10440735979787247431"
+      "templateHash": "4260162552164475821"
     }
   },
   "parameters": {
@@ -286,7 +286,10 @@
     },
     "joinedString": "[join(createArray('I', 'love', 'Bicep!'), ' ')]",
     "prefix": "[take('food', 3)]",
-    "isPrefixed": "[startsWith('food', 'foo')]"
+    "isPrefixed": "[startsWith('food', 'foo')]",
+    "spread": "[shallowMerge(createArray(createObject('foo', 'abc'), variables('issue1332')))]",
+    "test": "[shallowMerge(createArray(variables('spread'), createObject('bar', 'def')))]",
+    "arraySpread": "[flatten(createArray(variables('arrayOfBooleans'), variables('arrayOfHardCodedNumbers'), variables('arrayOfHardCodedStrings')))]"
   },
   "resources": {}
 }
\ No newline at end of file
diff --git a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.symbols.bicep b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.symbols.bicep
index 46e0f9ca183..9a2cd8f8390 100644
--- a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.symbols.bicep
+++ b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.symbols.bicep
@@ -493,3 +493,18 @@ var prefix = take('food', 3)
 var isPrefixed = startsWith('food', 'foo')
 //@[04:14) Variable isPrefixed. Type: true. Declaration start char: 0, length: 42
 
+var spread = {
+//@[04:10) Variable spread. Type: object. Declaration start char: 0, length: 44
+  foo: 'abc'
+  ...issue1332
+}
+
+var test = {
+//@[04:08) Variable test. Type: object. Declaration start char: 0, length: 39
+  ...spread
+  bar: 'def'
+}
+
+var arraySpread = [...arrayOfBooleans, ...arrayOfHardCodedNumbers, ...arrayOfHardCodedStrings]
+//@[04:15) Variable arraySpread. Type: ('hi' | 3 | bool)[]. Declaration start char: 0, length: 94
+
diff --git a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.syntax.bicep b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.syntax.bicep
index f1fb9213a4a..927ed7c8feb 100644
--- a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.syntax.bicep
+++ b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.syntax.bicep
@@ -1,5 +1,5 @@
 
-//@[000:7923) ProgramSyntax
+//@[000:8106) ProgramSyntax
 //@[000:0001) ├─Token(NewLine) |\n|
 // int
 //@[006:0007) ├─Token(NewLine) |\n|
@@ -3167,6 +3167,90 @@ var isPrefixed = startsWith('food', 'foo')
 //@[036:0041) |   | └─StringSyntax
 //@[036:0041) |   |   └─Token(StringComplete) |'foo'|
 //@[041:0042) |   └─Token(RightParen) |)|
-//@[042:0043) ├─Token(NewLine) |\n|
+//@[042:0044) ├─Token(NewLine) |\n\n|
+
+var spread = {
+//@[000:0044) ├─VariableDeclarationSyntax
+//@[000:0003) | ├─Token(Identifier) |var|
+//@[004:0010) | ├─IdentifierSyntax
+//@[004:0010) | | └─Token(Identifier) |spread|
+//@[011:0012) | ├─Token(Assignment) |=|
+//@[013:0044) | └─ObjectSyntax
+//@[013:0014) |   ├─Token(LeftBrace) |{|
+//@[014:0015) |   ├─Token(NewLine) |\n|
+  foo: 'abc'
+//@[002:0012) |   ├─ObjectPropertySyntax
+//@[002:0005) |   | ├─IdentifierSyntax
+//@[002:0005) |   | | └─Token(Identifier) |foo|
+//@[005:0006) |   | ├─Token(Colon) |:|
+//@[007:0012) |   | └─StringSyntax
+//@[007:0012) |   |   └─Token(StringComplete) |'abc'|
+//@[012:0013) |   ├─Token(NewLine) |\n|
+  ...issue1332
+//@[002:0014) |   ├─SpreadExpressionSyntax
+//@[002:0005) |   | ├─Token(Ellipsis) |...|
+//@[005:0014) |   | └─VariableAccessSyntax
+//@[005:0014) |   |   └─IdentifierSyntax
+//@[005:0014) |   |     └─Token(Identifier) |issue1332|
+//@[014:0015) |   ├─Token(NewLine) |\n|
+}
+//@[000:0001) |   └─Token(RightBrace) |}|
+//@[001:0003) ├─Token(NewLine) |\n\n|
+
+var test = {
+//@[000:0039) ├─VariableDeclarationSyntax
+//@[000:0003) | ├─Token(Identifier) |var|
+//@[004:0008) | ├─IdentifierSyntax
+//@[004:0008) | | └─Token(Identifier) |test|
+//@[009:0010) | ├─Token(Assignment) |=|
+//@[011:0039) | └─ObjectSyntax
+//@[011:0012) |   ├─Token(LeftBrace) |{|
+//@[012:0013) |   ├─Token(NewLine) |\n|
+  ...spread
+//@[002:0011) |   ├─SpreadExpressionSyntax
+//@[002:0005) |   | ├─Token(Ellipsis) |...|
+//@[005:0011) |   | └─VariableAccessSyntax
+//@[005:0011) |   |   └─IdentifierSyntax
+//@[005:0011) |   |     └─Token(Identifier) |spread|
+//@[011:0012) |   ├─Token(NewLine) |\n|
+  bar: 'def'
+//@[002:0012) |   ├─ObjectPropertySyntax
+//@[002:0005) |   | ├─IdentifierSyntax
+//@[002:0005) |   | | └─Token(Identifier) |bar|
+//@[005:0006) |   | ├─Token(Colon) |:|
+//@[007:0012) |   | └─StringSyntax
+//@[007:0012) |   |   └─Token(StringComplete) |'def'|
+//@[012:0013) |   ├─Token(NewLine) |\n|
+}
+//@[000:0001) |   └─Token(RightBrace) |}|
+//@[001:0003) ├─Token(NewLine) |\n\n|
+
+var arraySpread = [...arrayOfBooleans, ...arrayOfHardCodedNumbers, ...arrayOfHardCodedStrings]
+//@[000:0094) ├─VariableDeclarationSyntax
+//@[000:0003) | ├─Token(Identifier) |var|
+//@[004:0015) | ├─IdentifierSyntax
+//@[004:0015) | | └─Token(Identifier) |arraySpread|
+//@[016:0017) | ├─Token(Assignment) |=|
+//@[018:0094) | └─ArraySyntax
+//@[018:0019) |   ├─Token(LeftSquare) |[|
+//@[019:0037) |   ├─SpreadExpressionSyntax
+//@[019:0022) |   | ├─Token(Ellipsis) |...|
+//@[022:0037) |   | └─VariableAccessSyntax
+//@[022:0037) |   |   └─IdentifierSyntax
+//@[022:0037) |   |     └─Token(Identifier) |arrayOfBooleans|
+//@[037:0038) |   ├─Token(Comma) |,|
+//@[039:0065) |   ├─SpreadExpressionSyntax
+//@[039:0042) |   | ├─Token(Ellipsis) |...|
+//@[042:0065) |   | └─VariableAccessSyntax
+//@[042:0065) |   |   └─IdentifierSyntax
+//@[042:0065) |   |     └─Token(Identifier) |arrayOfHardCodedNumbers|
+//@[065:0066) |   ├─Token(Comma) |,|
+//@[067:0093) |   ├─SpreadExpressionSyntax
+//@[067:0070) |   | ├─Token(Ellipsis) |...|
+//@[070:0093) |   | └─VariableAccessSyntax
+//@[070:0093) |   |   └─IdentifierSyntax
+//@[070:0093) |   |     └─Token(Identifier) |arrayOfHardCodedStrings|
+//@[093:0094) |   └─Token(RightSquare) |]|
+//@[094:0095) ├─Token(NewLine) |\n|
 
 //@[000:0000) └─Token(EndOfFile) ||
diff --git a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.tokens.bicep b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.tokens.bicep
index ce4b0a49d46..bf258ab1f94 100644
--- a/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.tokens.bicep
+++ b/src/Bicep.Core.Samples/Files/baselines/Variables_LF/main.tokens.bicep
@@ -1992,6 +1992,60 @@ var isPrefixed = startsWith('food', 'foo')
 //@[034:035) Comma |,|
 //@[036:041) StringComplete |'foo'|
 //@[041:042) RightParen |)|
-//@[042:043) NewLine |\n|
+//@[042:044) NewLine |\n\n|
+
+var spread = {
+//@[000:003) Identifier |var|
+//@[004:010) Identifier |spread|
+//@[011:012) Assignment |=|
+//@[013:014) LeftBrace |{|
+//@[014:015) NewLine |\n|
+  foo: 'abc'
+//@[002:005) Identifier |foo|
+//@[005:006) Colon |:|
+//@[007:012) StringComplete |'abc'|
+//@[012:013) NewLine |\n|
+  ...issue1332
+//@[002:005) Ellipsis |...|
+//@[005:014) Identifier |issue1332|
+//@[014:015) NewLine |\n|
+}
+//@[000:001) RightBrace |}|
+//@[001:003) NewLine |\n\n|
+
+var test = {
+//@[000:003) Identifier |var|
+//@[004:008) Identifier |test|
+//@[009:010) Assignment |=|
+//@[011:012) LeftBrace |{|
+//@[012:013) NewLine |\n|
+  ...spread
+//@[002:005) Ellipsis |...|
+//@[005:011) Identifier |spread|
+//@[011:012) NewLine |\n|
+  bar: 'def'
+//@[002:005) Identifier |bar|
+//@[005:006) Colon |:|
+//@[007:012) StringComplete |'def'|
+//@[012:013) NewLine |\n|
+}
+//@[000:001) RightBrace |}|
+//@[001:003) NewLine |\n\n|
+
+var arraySpread = [...arrayOfBooleans, ...arrayOfHardCodedNumbers, ...arrayOfHardCodedStrings]
+//@[000:003) Identifier |var|
+//@[004:015) Identifier |arraySpread|
+//@[016:017) Assignment |=|
+//@[018:019) LeftSquare |[|
+//@[019:022) Ellipsis |...|
+//@[022:037) Identifier |arrayOfBooleans|
+//@[037:038) Comma |,|
+//@[039:042) Ellipsis |...|
+//@[042:065) Identifier |arrayOfHardCodedNumbers|
+//@[065:066) Comma |,|
+//@[067:070) Ellipsis |...|
+//@[070:093) Identifier |arrayOfHardCodedStrings|
+//@[093:094) RightSquare |]|
+//@[094:095) NewLine |\n|
 
 //@[000:000) EndOfFile ||
diff --git a/src/Bicep.Core.Samples/Files/baselines_bicepparam/Invalid_Expressions/parameters.diagnostics.bicepparam b/src/Bicep.Core.Samples/Files/baselines_bicepparam/Invalid_Expressions/parameters.diagnostics.bicepparam
index 223ff2f6b19..eca79224bec 100644
--- a/src/Bicep.Core.Samples/Files/baselines_bicepparam/Invalid_Expressions/parameters.diagnostics.bicepparam
+++ b/src/Bicep.Core.Samples/Files/baselines_bicepparam/Invalid_Expressions/parameters.diagnostics.bicepparam
@@ -31,6 +31,7 @@ param testEndsWith = endsWith('foo', [])
 param testFilter = filter([1, 2], i => i < 'foo')
 //@[19:49) [BCP033 (Error)] Expected a value of type "object" but the provided value is of type "(1 | 2)[]". (CodeDescription: none) |filter([1, 2], i => i < 'foo')|
 //@[19:49) [BCP338 (Error)] Failed to evaluate parameter "testFilter": The template language function 'less' expects two parameters of matching types. The function was invoked with values of type 'Integer' and 'String' that do not match. (CodeDescription: none) |filter([1, 2], i => i < 'foo')|
+//@[39:48) [BCP045 (Error)] Cannot apply operator "<" to operands of type "1 | 2" and "'foo'". (CodeDescription: none) |i < 'foo'|
 param testFirst = first('asdfds')
 //@[18:33) [BCP033 (Error)] Expected a value of type "object" but the provided value is of type "'a'". (CodeDescription: none) |first('asdfds')|
 param testFlatten = flatten({foo: 'bar'})
@@ -83,7 +84,9 @@ param testReplace = replace('abc', 'b', {})
 param testSkip = skip([1, 2, 3], '1')
 //@[33:36) [BCP070 (Error)] Argument of type "'1'" is not assignable to parameter of type "int". (CodeDescription: none) |'1'|
 param testSort = sort(['c', 'd', 'a'], (a, b) => a + b)
-//@[39:54) [BCP070 (Error)] Argument of type "(any, any) => int" is not assignable to parameter of type "(any, any) => bool". (CodeDescription: none) |(a, b) => a + b|
+//@[17:55) [BCP033 (Error)] Expected a value of type "object" but the provided value is of type "('a' | 'c' | 'd')[]". (CodeDescription: none) |sort(['c', 'd', 'a'], (a, b) => a + b)|
+//@[17:55) [BCP338 (Error)] Failed to evaluate parameter "testSort": Unhandled exception during evaluating template language function 'sort' is not handled. (CodeDescription: none) |sort(['c', 'd', 'a'], (a, b) => a + b)|
+//@[49:54) [BCP045 (Error)] Cannot apply operator "+" to operands of type "'a' | 'c' | 'd'" and "'a' | 'c' | 'd'". Use string interpolation instead. (CodeDescription: none) |a + b|
 param testSplit = split('a/b/c', 1 + 2)
 //@[33:38) [BCP070 (Error)] Argument of type "3" is not assignable to parameter of type "array | string". (CodeDescription: none) |1 + 2|
 param testStartsWith = startsWith('abc', {})
@@ -97,7 +100,7 @@ param testTake = take([1, 2, 3], '2')
 param testToLower = toLower(123)
 //@[28:31) [BCP070 (Error)] Argument of type "123" is not assignable to parameter of type "string". (CodeDescription: none) |123|
 param testToObject = toObject(['a', 'b', 'c'], x => {x: x}, x => 'Hi ${x}!')
-//@[47:58) [BCP070 (Error)] Argument of type "any => object" is not assignable to parameter of type "any => string". (CodeDescription: none) |x => {x: x}|
+//@[47:58) [BCP070 (Error)] Argument of type "('a' | 'b' | 'c') => object" is not assignable to parameter of type "any => string". (CodeDescription: none) |x => {x: x}|
 param testToUpper = toUpper([123])
 //@[28:33) [BCP070 (Error)] Argument of type "[123]" is not assignable to parameter of type "string". (CodeDescription: none) |[123]|
 param testTrim = trim(123)
diff --git a/src/Bicep.Core.Samples/Files/baselines_bicepparam/Invalid_Expressions/parameters.symbols.bicepparam b/src/Bicep.Core.Samples/Files/baselines_bicepparam/Invalid_Expressions/parameters.symbols.bicepparam
index e00b9bb724e..fbf9c193a49 100644
--- a/src/Bicep.Core.Samples/Files/baselines_bicepparam/Invalid_Expressions/parameters.symbols.bicepparam
+++ b/src/Bicep.Core.Samples/Files/baselines_bicepparam/Invalid_Expressions/parameters.symbols.bicepparam
@@ -73,7 +73,7 @@ param testReplace = replace('abc', 'b', {})
 param testSkip = skip([1, 2, 3], '1')
 //@[6:14) ParameterAssignment testSkip. Type: error. Declaration start char: 0, length: 37
 param testSort = sort(['c', 'd', 'a'], (a, b) => a + b)
-//@[6:14) ParameterAssignment testSort. Type: error. Declaration start char: 0, length: 55
+//@[6:14) ParameterAssignment testSort. Type: ('a' | 'c' | 'd')[]. Declaration start char: 0, length: 55
 param testSplit = split('a/b/c', 1 + 2)
 //@[6:15) ParameterAssignment testSplit. Type: error. Declaration start char: 0, length: 39
 param testStartsWith = startsWith('abc', {})
diff --git a/src/Bicep.Core.UnitTests/Diagnostics/ErrorBuilderTests.cs b/src/Bicep.Core.UnitTests/Diagnostics/ErrorBuilderTests.cs
index a9662748653..4bc6abd0c2a 100644
--- a/src/Bicep.Core.UnitTests/Diagnostics/ErrorBuilderTests.cs
+++ b/src/Bicep.Core.UnitTests/Diagnostics/ErrorBuilderTests.cs
@@ -193,6 +193,13 @@ private static object CreateMockParameter(ParameterInfo parameter, int index)
                     asClause: SyntaxFactory.EmptySkippedTrivia);
             }
 
+            if (parameter.ParameterType == typeof(SpreadExpressionSyntax))
+            {
+                return new SpreadExpressionSyntax(
+                    SyntaxFactory.EllipsisToken,
+                    TestSyntaxFactory.CreateVariableAccess("identifier"));
+            }
+
             if (parameter.ParameterType == typeof(ExportMetadataKind))
             {
                 return ExportMetadataKind.Error;
diff --git a/src/Bicep.Core/Diagnostics/DiagnosticBuilder.cs b/src/Bicep.Core/Diagnostics/DiagnosticBuilder.cs
index cf8c5c06844..5c5ae698a43 100644
--- a/src/Bicep.Core/Diagnostics/DiagnosticBuilder.cs
+++ b/src/Bicep.Core/Diagnostics/DiagnosticBuilder.cs
@@ -2166,6 +2166,16 @@ public FixableDiagnostic LegacyProviderSpecificationIsDeprecated(LegacyProviderS
                     DiagnosticStyling.Default,
                     codeFix);
             }
+
+            public ErrorDiagnostic SpreadOperatorUnsupportedInLocation(SpreadExpressionSyntax spread) => new(
+                TextSpan,
+                "BCP396",
+                $"The spread operator \"{spread.Ellipsis.Text}\" is not permitted in this location.");
+
+            public ErrorDiagnostic SpreadOperatorRequiresAssignableValue(SpreadExpressionSyntax spread, TypeSymbol requiredType) => new(
+                TextSpan,
+                "BCP397",
+                $"The spread operator \"{spread.Ellipsis.Text}\" can only be used in this context for an expression assignable to type \"{requiredType}\".");
         }
 
         public static DiagnosticBuilderInternal ForPosition(TextSpan span)
diff --git a/src/Bicep.Core/Emit/EmitLimitationCalculator.cs b/src/Bicep.Core/Emit/EmitLimitationCalculator.cs
index 1ca90630f75..fe9f1f682bd 100644
--- a/src/Bicep.Core/Emit/EmitLimitationCalculator.cs
+++ b/src/Bicep.Core/Emit/EmitLimitationCalculator.cs
@@ -53,6 +53,7 @@ public static EmitLimitationInfo Calculate(SemanticModel model)
             BlockAssertsWithoutExperimentalFeatures(model, diagnostics);
             BlockNamesDistinguishedOnlyByCase(model, diagnostics);
             BlockResourceDerivedTypesThatDoNotDereferenceProperties(model, diagnostics);
+            BlockSpreadInUnsupportedLocations(model, diagnostics);
 
             var paramAssignments = CalculateParameterAssignments(model, diagnostics);
 
@@ -682,5 +683,40 @@ TypeAdditionalPropertiesAccessSyntax or
                     !IsPermittedResourceDerivedTypeParent(model.Binder, model.Binder.GetParent(typeInstantiation)))
                 .Select(typeInstantiaion => DiagnosticBuilder.ForPosition(typeInstantiaion).CannotUseEntireResourceBodyAsType()));
         }
+
+        private static void BlockSpreadInUnsupportedLocations(SemanticModel model, IDiagnosticWriter diagnostics)
+        {
+            IEnumerable<ObjectSyntax> getObjectSyntaxesToBlock()
+            {
+                foreach (var module in model.Root.ModuleDeclarations)
+                {
+                    if (module.DeclaringModule.TryGetBody() is {} body)
+                    {
+                        yield return body;
+
+                        if (body.TryGetPropertyByName(LanguageConstants.ModuleParamsPropertyName)?.Value is ObjectSyntax paramsBody)
+                        {
+                            yield return paramsBody;
+                        }
+                    }
+                }
+
+                foreach (var resource in model.Root.ResourceDeclarations)
+                {
+                    if (resource.DeclaringResource.TryGetBody() is {} body)
+                    {
+                        yield return body;
+                    }
+                }
+            }
+
+            foreach (var body in getObjectSyntaxesToBlock())
+            {
+                foreach (var spread in body.Children.OfType<SpreadExpressionSyntax>())
+                {
+                    diagnostics.Write(spread, x => x.SpreadOperatorUnsupportedInLocation(spread));
+                }
+            }
+        }
     }
 }
diff --git a/src/Bicep.Core/Intermediate/ExpressionBuilder.cs b/src/Bicep.Core/Intermediate/ExpressionBuilder.cs
index 5d7246e8e0f..b3d2f4b23ff 100644
--- a/src/Bicep.Core/Intermediate/ExpressionBuilder.cs
+++ b/src/Bicep.Core/Intermediate/ExpressionBuilder.cs
@@ -101,8 +101,7 @@ private Expression ConvertWithoutLowering(SyntaxBase syntax)
             case ObjectSyntax @object:
                 return ConvertObject(@object);
             case ArraySyntax array:
-                var items = array.Items.Select(x => ConvertWithoutLowering(x.Value));
-                return new ArrayExpression(array, items.ToImmutableArray());
+                return ConvertArray(array);
             case TernaryOperationSyntax ternary:
                 return new TernaryExpression(
                     ternary,
@@ -741,10 +740,81 @@ void AddLoop(LoopExpressionContext newLoop)
             dependencies);
     }
 
-    private ObjectExpression ConvertObject(ObjectSyntax @object)
-        => new(
-            @object,
-            @object.Properties.Select(ConvertObjectProperty).ToImmutableArray());
+    private Expression ConvertArray(ArraySyntax array)
+    {
+        var hasSpread = false;
+        var chunks = new List<Expression>();
+        var currentChunk = new List<Expression>();
+        void completePreviousChunk()
+        {
+            if (currentChunk.Count > 0)
+            {
+                chunks.Add(new ArrayExpression(array, currentChunk.ToImmutableArray()));
+                currentChunk.Clear();
+            }
+        }
+
+        foreach (var child in array.Children)
+        {
+            if (child is SpreadExpressionSyntax spread)
+            {
+                completePreviousChunk();
+                chunks.Add(ConvertWithoutLowering(spread.Expression));
+                hasSpread = true;
+            }
+            else if (child is ArrayItemSyntax arrayItem)
+            {
+                currentChunk.Add(ConvertWithoutLowering(arrayItem.Value));
+            }
+        }
+        completePreviousChunk();
+
+        return chunks.Count switch
+        {
+            0 => new ArrayExpression(array, []),
+            // preserve [ ...[ bar ] ] rather than converting it to [ foo: bar ]
+            1 when !hasSpread => chunks[0],
+            _ => new FunctionCallExpression(array, "flatten", [new ArrayExpression(array, chunks.ToImmutableArray())]),
+        };
+    }
+
+    private Expression ConvertObject(ObjectSyntax @object)
+    {
+        var hasSpread = false;
+        var chunks = new List<Expression>();
+        var currentChunk = new List<ObjectPropertyExpression>();
+        void completePreviousChunk()
+        {
+            if (currentChunk.Count > 0)
+            {
+                chunks.Add(new ObjectExpression(@object, currentChunk.ToImmutableArray()));
+                currentChunk.Clear();
+            }
+        }
+
+        foreach (var child in @object.Children)
+        {
+            if (child is SpreadExpressionSyntax spread)
+            {
+                completePreviousChunk();
+                chunks.Add(ConvertWithoutLowering(spread.Expression));
+                hasSpread = true;
+            }
+            else if (child is ObjectPropertySyntax objectProperty)
+            {
+                currentChunk.Add(ConvertObjectProperty(objectProperty));
+            }
+        }
+        completePreviousChunk();
+
+        return chunks.Count switch
+        {
+            0 => new ObjectExpression(@object, []),
+            // preserve { ...{ foo: bar } } rather than converting it to { foo: bar }
+            1 when !hasSpread => chunks[0],
+            _ => new FunctionCallExpression(@object, "shallowMerge", [new ArrayExpression(@object, chunks.ToImmutableArray())]),
+        };
+    }
 
     private ObjectPropertyExpression ConvertObjectProperty(ObjectPropertySyntax syntax)
     {
diff --git a/src/Bicep.Core/Parsing/BaseParser.cs b/src/Bicep.Core/Parsing/BaseParser.cs
index 5b9fdff37a2..274549ae10a 100644
--- a/src/Bicep.Core/Parsing/BaseParser.cs
+++ b/src/Bicep.Core/Parsing/BaseParser.cs
@@ -207,17 +207,24 @@ private SyntaxBase Array()
 
             var itemsOrTokens = HandleArrayOrObjectElements(
                 closingTokenType: TokenType.RightSquare,
-                parseChildElement: ArrayItem);
+                parseChildElement: ArrayElement);
 
             var closeBracket = Expect(TokenType.RightSquare, b => b.ExpectedCharacter("]"));
 
             return new ArraySyntax(openBracket, itemsOrTokens, closeBracket);
         }
 
-        private SyntaxBase ArrayItem()
+        private SyntaxBase ArrayElement()
         {
             return this.WithRecovery<SyntaxBase>(() =>
             {
+                var current = this.reader.Peek();
+
+                if (current.Type == TokenType.Ellipsis)
+                {
+                    return SpreadExpression([TokenType.NewLine, TokenType.RightSquare]);
+                }
+
                 var value = this.Expression(ExpressionFlags.AllowComplexLiterals);
 
                 return new ArrayItemSyntax(value);
@@ -1057,14 +1064,22 @@ protected ObjectSyntax Object(ExpressionFlags expressionFlags)
 
             var itemsOrTokens = HandleArrayOrObjectElements(
                 closingTokenType: TokenType.RightBrace,
-                parseChildElement: () => ObjectProperty(expressionFlags));
+                parseChildElement: () => ObjectElement(expressionFlags));
 
             var closeBrace = Expect(TokenType.RightBrace, b => b.ExpectedCharacter("}"));
 
             return new ObjectSyntax(openBrace, itemsOrTokens, closeBrace);
         }
 
-        private SyntaxBase ObjectProperty(ExpressionFlags expressionFlags)
+        private SpreadExpressionSyntax SpreadExpression(TokenType[] terminatingTypes)
+        {
+            var ellipsis = this.Expect(TokenType.Ellipsis, b => b.ExpectedCharacter("..."));
+            var expression = this.WithRecovery(() => this.Expression(ExpressionFlags.AllowComplexLiterals), GetSuppressionFlag(ellipsis), terminatingTypes);
+
+            return new SpreadExpressionSyntax(ellipsis, expression);
+        }
+
+        private SyntaxBase ObjectElement(ExpressionFlags expressionFlags)
         {
             return this.WithRecovery<SyntaxBase>(() =>
             {
@@ -1087,6 +1102,11 @@ private SyntaxBase ObjectProperty(ExpressionFlags expressionFlags)
                     return this.Declaration(LanguageConstants.ResourceKeyword);
                 }
 
+                if (current.Type == TokenType.Ellipsis)
+                {
+                    return SpreadExpression([TokenType.NewLine, TokenType.RightBrace]);
+                }
+
                 var key = this.WithRecovery(
                     () => ThrowIfSkipped(
                         () =>
diff --git a/src/Bicep.Core/Parsing/Lexer.cs b/src/Bicep.Core/Parsing/Lexer.cs
index 0b549b10df6..885cdb2426d 100644
--- a/src/Bicep.Core/Parsing/Lexer.cs
+++ b/src/Bicep.Core/Parsing/Lexer.cs
@@ -900,6 +900,12 @@ private TokenType ScanToken()
                 case ',':
                     return TokenType.Comma;
                 case '.':
+                    switch (textWindow.Peek(), textWindow.Peek(1))
+                    {
+                        case ('.', '.'):
+                            textWindow.Advance(2);
+                            return TokenType.Ellipsis;
+                    }
                     return TokenType.Dot;
                 case '?':
                     if (!textWindow.IsAtEnd())
diff --git a/src/Bicep.Core/Parsing/TokenType.cs b/src/Bicep.Core/Parsing/TokenType.cs
index 9212a3cae7c..1b9c6e6e9fa 100644
--- a/src/Bicep.Core/Parsing/TokenType.cs
+++ b/src/Bicep.Core/Parsing/TokenType.cs
@@ -52,5 +52,6 @@ public enum TokenType
         Pipe,
         WithKeyword,
         AsKeyword,
+        Ellipsis,
     }
 }
diff --git a/src/Bicep.Core/PrettyPrintV2/SyntaxLayouts.SyntaxVisitor.cs b/src/Bicep.Core/PrettyPrintV2/SyntaxLayouts.SyntaxVisitor.cs
index 18205463c8e..6b57d59c62b 100644
--- a/src/Bicep.Core/PrettyPrintV2/SyntaxLayouts.SyntaxVisitor.cs
+++ b/src/Bicep.Core/PrettyPrintV2/SyntaxLayouts.SyntaxVisitor.cs
@@ -174,6 +174,8 @@ public void VisitTypeAdditionalPropertiesAccessSyntax(TypeAdditionalPropertiesAc
 
         public void VisitTypeItemsAccessSyntax(TypeItemsAccessSyntax syntax) => this.Apply(syntax, LayoutTypeItemsAccessSyntax);
 
+        public void VisitSpreadExpressionSyntax(SpreadExpressionSyntax syntax) => this.Apply(syntax, LayoutSpreadExpressionSyntax);
+
         public IEnumerable<Document> Layout(SyntaxBase syntax)
         {
             syntax.Accept(this);
diff --git a/src/Bicep.Core/PrettyPrintV2/SyntaxLayouts.cs b/src/Bicep.Core/PrettyPrintV2/SyntaxLayouts.cs
index f81af416272..6420f5e7827 100644
--- a/src/Bicep.Core/PrettyPrintV2/SyntaxLayouts.cs
+++ b/src/Bicep.Core/PrettyPrintV2/SyntaxLayouts.cs
@@ -603,6 +603,9 @@ private IEnumerable<Document> LayoutInstanceParameterizedTypeInstantiationSyntax
         private IEnumerable<Document> LayoutTypeItemsAccessSyntax(TypeItemsAccessSyntax syntax) =>
             this.Glue(syntax.BaseExpression, syntax.OpenSquare, syntax.Asterisk, syntax.CloseSquare);
 
+        private IEnumerable<Document> LayoutSpreadExpressionSyntax(SpreadExpressionSyntax syntax) =>
+            this.Glue(syntax.Ellipsis, syntax.Expression);
+
         private IEnumerable<Document> LayoutLeadingNodes(IEnumerable<SyntaxBase> leadingNodes) =>
             this.LayoutMany(leadingNodes)
                 .Where(x => x != HardLine); // Remove empty lines between decorators.
diff --git a/src/Bicep.Core/Rewriters/DependsOnRemovalRewriter.cs b/src/Bicep.Core/Rewriters/DependsOnRemovalRewriter.cs
index b17bf76a357..9ded00879b1 100644
--- a/src/Bicep.Core/Rewriters/DependsOnRemovalRewriter.cs
+++ b/src/Bicep.Core/Rewriters/DependsOnRemovalRewriter.cs
@@ -59,14 +59,14 @@ value switch
             }
 
             var builtInDependencies = new HashSet<Symbol>();
-            foreach (var property in @object.Properties)
+            foreach (var child in @object.Children)
             {
-                if (property == dependsOnProperty)
+                if (child == dependsOnProperty)
                 {
                     continue;
                 }
 
-                var dependencies = ResourceDependencyFinderVisitor.GetResourceDependencies(semanticModel, property);
+                var dependencies = ResourceDependencyFinderVisitor.GetResourceDependencies(semanticModel, child);
                 builtInDependencies.UnionWith(dependencies);
             }
 
diff --git a/src/Bicep.Core/Syntax/AstVisitor.cs b/src/Bicep.Core/Syntax/AstVisitor.cs
index 6318b94c2fc..6753d6c24ed 100644
--- a/src/Bicep.Core/Syntax/AstVisitor.cs
+++ b/src/Bicep.Core/Syntax/AstVisitor.cs
@@ -454,5 +454,10 @@ public override void VisitTypeItemsAccessSyntax(TypeItemsAccessSyntax syntax)
         {
             this.Visit(syntax.BaseExpression);
         }
+
+        public override void VisitSpreadExpressionSyntax(SpreadExpressionSyntax syntax)
+        {
+            this.Visit(syntax.Expression);
+        }
     }
 }
diff --git a/src/Bicep.Core/Syntax/CstVisitor.cs b/src/Bicep.Core/Syntax/CstVisitor.cs
index 476157c4e9b..567d8c1a72b 100644
--- a/src/Bicep.Core/Syntax/CstVisitor.cs
+++ b/src/Bicep.Core/Syntax/CstVisitor.cs
@@ -569,5 +569,11 @@ public override void VisitTypeItemsAccessSyntax(TypeItemsAccessSyntax syntax)
             this.Visit(syntax.Asterisk);
             this.Visit(syntax.CloseSquare);
         }
+
+        public override void VisitSpreadExpressionSyntax(SpreadExpressionSyntax syntax)
+        {
+            this.Visit(syntax.Ellipsis);
+            this.Visit(syntax.Expression);
+        }
     }
 }
diff --git a/src/Bicep.Core/Syntax/ISyntaxVisitor.cs b/src/Bicep.Core/Syntax/ISyntaxVisitor.cs
index ee8b458dd9c..ac4391e7d16 100644
--- a/src/Bicep.Core/Syntax/ISyntaxVisitor.cs
+++ b/src/Bicep.Core/Syntax/ISyntaxVisitor.cs
@@ -155,5 +155,7 @@ public interface ISyntaxVisitor
         void VisitTypeArrayAccessSyntax(TypeArrayAccessSyntax syntax);
 
         void VisitTypeItemsAccessSyntax(TypeItemsAccessSyntax syntax);
+
+        void VisitSpreadExpressionSyntax(SpreadExpressionSyntax syntax);
     }
 }
diff --git a/src/Bicep.Core/Syntax/ObjectSyntaxExtensions.cs b/src/Bicep.Core/Syntax/ObjectSyntaxExtensions.cs
index 09830a7eb3d..a63441eb86e 100644
--- a/src/Bicep.Core/Syntax/ObjectSyntaxExtensions.cs
+++ b/src/Bicep.Core/Syntax/ObjectSyntaxExtensions.cs
@@ -29,13 +29,6 @@ public static class ObjectSyntaxExtensions
             return dictionary.ToImmutableDictionary(LanguageConstants.IdentifierComparer);
         }
 
-        /// <summary>
-        /// Converts a syntactically valid object syntax node to a dictionary mapping property name strings to property syntax node values. Returns the first property value in the case of duplicate names.
-        /// </summary>
-        /// <param name="syntax">The object syntax node</param>
-        public static ImmutableDictionary<string, SyntaxBase> ToNamedPropertyValueDictionary(this ObjectSyntax syntax)
-            => ToNamedPropertyDictionary(syntax).ToImmutableDictionary(x => x.Key, x => x.Value.Value, LanguageConstants.IdentifierComparer);
-
         /// <summary>
         /// Returns the specified property by name on any valid or invalid object syntax node if there is exactly one property by that name.
         /// Returns null if the property does not exist or if multiple properties by that name exist. This method is intended for a single
diff --git a/src/Bicep.Core/Syntax/SpreadExpressionSyntax.cs b/src/Bicep.Core/Syntax/SpreadExpressionSyntax.cs
new file mode 100644
index 00000000000..d104ad76a77
--- /dev/null
+++ b/src/Bicep.Core/Syntax/SpreadExpressionSyntax.cs
@@ -0,0 +1,24 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+using Bicep.Core.Parsing;
+
+namespace Bicep.Core.Syntax;
+
+public class SpreadExpressionSyntax : ExpressionSyntax
+{
+    public SpreadExpressionSyntax(Token ellipsis, SyntaxBase expression)
+    {
+        AssertTokenType(ellipsis, nameof(ellipsis), TokenType.Ellipsis);
+
+        this.Ellipsis = ellipsis;
+        this.Expression = expression;
+    }
+
+    public Token Ellipsis { get; }
+
+    public SyntaxBase Expression { get; }
+
+    public override void Accept(ISyntaxVisitor visitor) => visitor.VisitSpreadExpressionSyntax(this);
+
+    public override TextSpan Span => TextSpan.Between(this.Ellipsis, this.Expression);
+}
\ No newline at end of file
diff --git a/src/Bicep.Core/Syntax/SyntaxFactory.cs b/src/Bicep.Core/Syntax/SyntaxFactory.cs
index b1ee5d90596..69cca9b3995 100644
--- a/src/Bicep.Core/Syntax/SyntaxFactory.cs
+++ b/src/Bicep.Core/Syntax/SyntaxFactory.cs
@@ -88,6 +88,7 @@ public static Token GetCommaToken(IEnumerable<SyntaxTrivia>? leadingTrivia = nul
         public static Token NullKeywordToken => CreateToken(TokenType.NullKeyword);
         public static Token ArrowToken => CreateToken(TokenType.Arrow);
         public static Token EndOfFileToken => CreateToken(TokenType.EndOfFile);
+        public static Token EllipsisToken => CreateToken(TokenType.Ellipsis);
 
         public static Token TargetScopeKeywordToken => CreateIdentifierTokenWithTrailingSpace(LanguageConstants.TargetScopeKeyword);
         public static Token ImportKeywordToken => CreateIdentifierTokenWithTrailingSpace(LanguageConstants.ImportKeyword);
diff --git a/src/Bicep.Core/Syntax/SyntaxFacts.cs b/src/Bicep.Core/Syntax/SyntaxFacts.cs
index 856facef425..c03a37f6c09 100644
--- a/src/Bicep.Core/Syntax/SyntaxFacts.cs
+++ b/src/Bicep.Core/Syntax/SyntaxFacts.cs
@@ -62,6 +62,7 @@ TokenType.MultilineString or
             TokenType.Pipe => "|",
             TokenType.WithKeyword => "with",
             TokenType.AsKeyword => "as",
+            TokenType.Ellipsis => "...",
             _ => null,
         };
 
diff --git a/src/Bicep.Core/Syntax/SyntaxRewriteVisitor.cs b/src/Bicep.Core/Syntax/SyntaxRewriteVisitor.cs
index 06dcc765963..50b08469dad 100644
--- a/src/Bicep.Core/Syntax/SyntaxRewriteVisitor.cs
+++ b/src/Bicep.Core/Syntax/SyntaxRewriteVisitor.cs
@@ -1252,5 +1252,19 @@ protected virtual SyntaxBase ReplaceParameterizedTypeArgumentSyntax(Parameterize
             return new ParameterizedTypeArgumentSyntax(expression);
         }
         void ISyntaxVisitor.VisitParameterizedTypeArgumentSyntax(ParameterizedTypeArgumentSyntax syntax) => ReplaceCurrent(syntax, ReplaceParameterizedTypeArgumentSyntax);
+
+        protected virtual SyntaxBase ReplaceSpreadExpressionSyntax(SpreadExpressionSyntax syntax)
+        {
+            var hasChanges = TryRewriteStrict(syntax.Ellipsis, out var ellipsis);
+            hasChanges |= TryRewriteStrict(syntax.Expression, out var expression);
+
+            if (!hasChanges)
+            {
+                return syntax;
+            }
+
+            return new SpreadExpressionSyntax(ellipsis, expression);
+        }
+        void ISyntaxVisitor.VisitSpreadExpressionSyntax(SpreadExpressionSyntax syntax) => ReplaceCurrent(syntax, ReplaceSpreadExpressionSyntax);
     }
 }
diff --git a/src/Bicep.Core/Syntax/SyntaxVisitor.cs b/src/Bicep.Core/Syntax/SyntaxVisitor.cs
index ca47ad1b238..e87bb3fdcdc 100644
--- a/src/Bicep.Core/Syntax/SyntaxVisitor.cs
+++ b/src/Bicep.Core/Syntax/SyntaxVisitor.cs
@@ -160,6 +160,8 @@ public abstract class SyntaxVisitor : ISyntaxVisitor
 
         public abstract void VisitTypeItemsAccessSyntax(TypeItemsAccessSyntax syntax);
 
+        public abstract void VisitSpreadExpressionSyntax(SpreadExpressionSyntax syntax);
+
         public void Visit(SyntaxBase? node)
         {
             if (node == null)
diff --git a/src/Bicep.Core/TypeSystem/TypeAssignmentVisitor.cs b/src/Bicep.Core/TypeSystem/TypeAssignmentVisitor.cs
index 5e621c3674b..6abb47177ce 100644
--- a/src/Bicep.Core/TypeSystem/TypeAssignmentVisitor.cs
+++ b/src/Bicep.Core/TypeSystem/TypeAssignmentVisitor.cs
@@ -3,6 +3,7 @@
 
 using System.Collections.Concurrent;
 using System.Collections.Immutable;
+using Azure.Deployments.Templates.Export;
 using Bicep.Core.Diagnostics;
 using Bicep.Core.Emit;
 using Bicep.Core.Extensions;
@@ -1187,15 +1188,32 @@ public override void VisitObjectSyntax(ObjectSyntax syntax)
                     }
                 }
 
-                var propertyTypes = new List<TypeSymbol>();
-                foreach (var objectProperty in syntax.Properties)
+                var childTypes = new List<TypeSymbol>();
+                foreach (var child in syntax.Children)
                 {
-                    var propertyType = typeManager.GetTypeInfo(objectProperty);
-                    CollectErrors(errors, propertyType);
-                    propertyTypes.Add(propertyType);
+                    var childType = child switch {
+                        ObjectPropertySyntax x => typeManager.GetTypeInfo(x),
+                        SpreadExpressionSyntax x => typeManager.GetTypeInfo(x.Expression),
+                        _ => null,
+                    };
+
+                    if (childType is null)
+                    {
+                        continue;
+                    }
+
+                    if (child is SpreadExpressionSyntax spread && 
+                        childType is not ErrorType &&
+                        !TypeValidator.AreTypesAssignable(childType, LanguageConstants.Object))
+                    {
+                        childType = ErrorType.Create(DiagnosticBuilder.ForPosition(child).SpreadOperatorRequiresAssignableValue(spread, LanguageConstants.Object));
+                    }
+
+                    CollectErrors(errors, childType);
+                    childTypes.Add(childType);
                 }
 
-                if (PropagateErrorType(errors, propertyTypes))
+                if (PropagateErrorType(errors, childTypes))
                 {
                     return ErrorType.Create(errors);
                 }
@@ -1203,33 +1221,61 @@ public override void VisitObjectSyntax(ObjectSyntax syntax)
                 // Discriminated objects should have been resolved by the declared type manager.
                 var declaredType = typeManager.GetDeclaredType(syntax);
 
-                // type results are cached
-                var namedProperties = syntax.Properties
-                    .GroupByExcludingNull(p => p.TryGetKeyText(), LanguageConstants.IdentifierComparer)
-                    .Select(group =>
+                var namedProperties = new Dictionary<string, TypeProperty>(LanguageConstants.IdentifierComparer);
+                var additionalProperties = new List<TypeSymbol>();
+                foreach (var child in syntax.Children)
+                {
+                    if (child is ObjectPropertySyntax propertySyntax)
                     {
-                        var resolvedType = TypeHelper.CreateTypeUnion(group.Select(p => typeManager.GetTypeInfo(p)));
+                        var resolvedType = typeManager.GetTypeInfo(propertySyntax);
 
-                        if (declaredType is ObjectType objectType && objectType.Properties.TryGetValue(group.Key, out var property))
+                        if (propertySyntax.TryGetKeyText() is {} name)
                         {
-                            // we've found a declared object type for the containing object, with a matching property name definition.
-                            // preserve the type property details (name, descriptions etc.), and update the assigned type.
-                            return new TypeProperty(property.Name, resolvedType, property.Flags, property.Description);
+                            if (declaredType is ObjectType objectType && objectType.Properties.TryGetValue(name, out var property))
+                            {
+                                // we've found a declared object type for the containing object, with a matching property name definition.
+                                // preserve the type property details (name, descriptions etc.), and update the assigned type.
+                                namedProperties[name] = new TypeProperty(property.Name, resolvedType, property.Flags, property.Description);
+                            }
+                            else
+                            {
+                                // we've not been able to find a declared object type for the containing object, or it doesn't contain a property matching this one.
+                                // best we can do is to simply generate a property for the assigned type.
+                                namedProperties[name] = new TypeProperty(name, resolvedType, TypePropertyFlags.Required);
+                            }
                         }
+                        else
+                        {
+                            additionalProperties.Add(resolvedType);
+                        }
+                    }
 
-                        // we've not been able to find a declared object type for the containing object, or it doesn't contain a property matching this one.
-                        // best we can do is to simply generate a property for the assigned type.
-                        return new TypeProperty(group.Key, resolvedType, TypePropertyFlags.Required);
-                    });
+                    if (child is SpreadExpressionSyntax spreadSyntax)
+                    {
+                        var type = typeManager.GetTypeInfo(spreadSyntax.Expression);
+                        if (type is ObjectType spreadType)
+                        {
+                            foreach (var (name, property) in spreadType.Properties)
+                            {
+                                namedProperties[name] = property;
+                            }
 
-                var additionalProperties = syntax.Properties
-                    .Where(p => p.TryGetKeyText() is null)
-                    .Select(p => typeManager.GetTypeInfo(p));
+                            if (spreadType.AdditionalPropertiesType is {})
+                            {
+                                additionalProperties.Add(spreadType.AdditionalPropertiesType.Type);
+                            }
+                        }
+                        else
+                        {
+                            additionalProperties.Add(LanguageConstants.Any);
+                        }
+                    }
+                }
 
                 var additionalPropertiesType = additionalProperties.Any() ? TypeHelper.CreateTypeUnion(additionalProperties) : null;
 
                 // TODO: Add structural naming?
-                return new ObjectType(LanguageConstants.Object.Name, TypeSymbolValidationFlags.Default, namedProperties, additionalPropertiesType);
+                return new ObjectType(LanguageConstants.Object.Name, TypeSymbolValidationFlags.Default, namedProperties.Values, additionalPropertiesType);
             });
 
         public override void VisitObjectPropertySyntax(ObjectPropertySyntax syntax)
@@ -1271,22 +1317,70 @@ public override void VisitArraySyntax(ArraySyntax syntax)
             {
                 var errors = new List<ErrorDiagnostic>();
 
-                var itemTypes = new List<TypeSymbol>(syntax.Children.Length);
-                TupleTypeNameBuilder typeName = new();
-                foreach (var arrayItem in syntax.Items)
+                var childTypes = new List<TypeSymbol>(syntax.Children.Length);
+
+                foreach (var child in syntax.Children)
                 {
-                    var itemType = typeManager.GetTypeInfo(arrayItem);
-                    itemTypes.Add(itemType);
-                    typeName.AppendItem(itemType.Name);
-                    CollectErrors(errors, itemType);
+                    var childType = child switch {
+                        ArrayItemSyntax x => typeManager.GetTypeInfo(x.Value),
+                        SpreadExpressionSyntax x => typeManager.GetTypeInfo(x.Expression),
+                        _ => null,
+                    };
+
+                    if (childType is null)
+                    {
+                        continue;
+                    }
+
+                    if (child is SpreadExpressionSyntax spread && 
+                        childType is not ErrorType &&
+                        !TypeValidator.AreTypesAssignable(childType, LanguageConstants.Array))
+                    {
+                        childType = ErrorType.Create(DiagnosticBuilder.ForPosition(child).SpreadOperatorRequiresAssignableValue(spread, LanguageConstants.Array));
+                    }
+
+                    CollectErrors(errors, childType);
+                    childTypes.Add(childType);
                 }
 
-                if (PropagateErrorType(errors, itemTypes))
+                if (PropagateErrorType(errors, childTypes))
                 {
                     return ErrorType.Create(errors);
                 }
 
-                return new TupleType(typeName.ToString(), itemTypes.ToImmutableArray<ITypeReference>(), TypeSymbolValidationFlags.Default);
+                var tupleEntries = new List<TypeSymbol>();
+                var itemEntries = new List<TypeSymbol>();
+                foreach (var child in syntax.Children)
+                {
+                    if (child is ArrayItemSyntax arrayItemSyntax)
+                    {
+                        tupleEntries.Add(typeManager.GetTypeInfo(child));
+                    }
+                    else if (child is SpreadExpressionSyntax spreadSyntax)
+                    {
+                        var type = typeManager.GetTypeInfo(spreadSyntax.Expression);
+                        if (type is TupleType spreadType)
+                        {
+                            tupleEntries.AddRange(spreadType.Items.Select(x => x.Type));
+                        }
+                        else if (type is ArrayType arrayType)
+                        {
+                            itemEntries.Add(arrayType.Item.Type);
+                        }
+                        else
+                        {
+                            itemEntries.Add(LanguageConstants.Any);
+                        }
+                    }
+                }
+
+                if (itemEntries.Any())
+                {
+                    var itemType = TypeHelper.CreateTypeUnion(tupleEntries.Concat(itemEntries));
+                    return new TypedArrayType(itemType, TypeSymbolValidationFlags.Default);
+                }
+
+                return new TupleType(tupleEntries.ToImmutableArray<ITypeReference>(), TypeSymbolValidationFlags.Default);
             });
 
         public override void VisitTernaryOperationSyntax(TernaryOperationSyntax syntax)
diff --git a/src/Bicep.Decompiler.IntegrationTests/Files/Working/lambdas/main.bicep b/src/Bicep.Decompiler.IntegrationTests/Files/Working/lambdas/main.bicep
index 430620ab1f9..2227199fdd1 100644
--- a/src/Bicep.Decompiler.IntegrationTests/Files/Working/lambdas/main.bicep
+++ b/src/Bicep.Decompiler.IntegrationTests/Files/Working/lambdas/main.bicep
@@ -6,16 +6,16 @@ var doggos = [
 ]
 var numbers = range(0, 4)
 var sayHello = map(doggos, i => 'Hello ${i}!')
-//@[4:12) [no-unused-vars (Warning)] Variable "sayHello" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sayHello|
+//@[04:12) [no-unused-vars (Warning)] Variable "sayHello" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sayHello|
 var isEven = filter(numbers, i => (0 == (i % 2)))
-//@[4:10) [no-unused-vars (Warning)] Variable "isEven" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |isEven|
+//@[04:10) [no-unused-vars (Warning)] Variable "isEven" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |isEven|
 var evenDoggosNestedLambdas = map(
-//@[4:27) [no-unused-vars (Warning)] Variable "evenDoggosNestedLambdas" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |evenDoggosNestedLambdas|
+//@[04:27) [no-unused-vars (Warning)] Variable "evenDoggosNestedLambdas" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |evenDoggosNestedLambdas|
   filter(numbers, i => contains(filter(numbers, j => (0 == (j % 2))), i)),
   x => doggos[x]
 )
 var flattenedArrayOfArrays = flatten([
-//@[4:26) [no-unused-vars (Warning)] Variable "flattenedArrayOfArrays" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |flattenedArrayOfArrays|
+//@[04:26) [no-unused-vars (Warning)] Variable "flattenedArrayOfArrays" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |flattenedArrayOfArrays|
   [
     0
     1
@@ -30,9 +30,9 @@ var flattenedArrayOfArrays = flatten([
   ]
 ])
 var flattenedEmptyArray = flatten([])
-//@[4:23) [no-unused-vars (Warning)] Variable "flattenedEmptyArray" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |flattenedEmptyArray|
+//@[04:23) [no-unused-vars (Warning)] Variable "flattenedEmptyArray" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |flattenedEmptyArray|
 var mapSayHi = map(
-//@[4:12) [no-unused-vars (Warning)] Variable "mapSayHi" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mapSayHi|
+//@[04:12) [no-unused-vars (Warning)] Variable "mapSayHi" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mapSayHi|
   [
     'abc'
     'def'
@@ -41,7 +41,7 @@ var mapSayHi = map(
   foo => 'Hi ${foo}!'
 )
 var mapEmpty = map([], foo => 'Hi ${foo}!')
-//@[4:12) [no-unused-vars (Warning)] Variable "mapEmpty" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mapEmpty|
+//@[04:12) [no-unused-vars (Warning)] Variable "mapEmpty" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mapEmpty|
 var mapObject = map(
   range(0, length(doggos)),
   i => {
@@ -51,7 +51,7 @@ var mapObject = map(
   }
 )
 var mapArray = flatten(map(
-//@[4:12) [no-unused-vars (Warning)] Variable "mapArray" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mapArray|
+//@[04:12) [no-unused-vars (Warning)] Variable "mapArray" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mapArray|
   range(1, 3),
   i => [
     (i * 2)
@@ -59,7 +59,7 @@ var mapArray = flatten(map(
   ]
 ))
 var mapMultiLineArray = flatten(map(
-//@[4:21) [no-unused-vars (Warning)] Variable "mapMultiLineArray" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mapMultiLineArray|
+//@[04:21) [no-unused-vars (Warning)] Variable "mapMultiLineArray" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |mapMultiLineArray|
   range(1, 3),
   i => [
     (i * 3)
@@ -68,7 +68,7 @@ var mapMultiLineArray = flatten(map(
   ]
 ))
 var filterEqualityCheck = filter(
-//@[4:23) [no-unused-vars (Warning)] Variable "filterEqualityCheck" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |filterEqualityCheck|
+//@[04:23) [no-unused-vars (Warning)] Variable "filterEqualityCheck" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |filterEqualityCheck|
   [
     'abc'
     'def'
@@ -77,9 +77,9 @@ var filterEqualityCheck = filter(
   foo => ('def' == foo)
 )
 var filterEmpty = filter([], foo => ('def' == foo))
-//@[4:15) [no-unused-vars (Warning)] Variable "filterEmpty" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |filterEmpty|
+//@[04:15) [no-unused-vars (Warning)] Variable "filterEmpty" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |filterEmpty|
 var sortNumeric = sort(
-//@[4:15) [no-unused-vars (Warning)] Variable "sortNumeric" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sortNumeric|
+//@[04:15) [no-unused-vars (Warning)] Variable "sortNumeric" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sortNumeric|
   [
     8
     3
@@ -90,7 +90,7 @@ var sortNumeric = sort(
   (x, y) => (x < y)
 )
 var sortAlpha = sort(
-//@[4:13) [no-unused-vars (Warning)] Variable "sortAlpha" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sortAlpha|
+//@[04:13) [no-unused-vars (Warning)] Variable "sortAlpha" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sortAlpha|
   [
     'ghi'
     'abc'
@@ -99,7 +99,7 @@ var sortAlpha = sort(
   (x, y) => (x < y)
 )
 var sortAlphaReverse = sort(
-//@[4:20) [no-unused-vars (Warning)] Variable "sortAlphaReverse" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sortAlphaReverse|
+//@[04:20) [no-unused-vars (Warning)] Variable "sortAlphaReverse" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sortAlphaReverse|
   [
     'ghi'
     'abc'
@@ -129,9 +129,9 @@ var sortByObjectKey = sort(
   (x, y) => (int(x.key) < int(y.key))
 )
 var sortEmpty = sort([], (x, y) => (int(x) < int(y)))
-//@[4:13) [no-unused-vars (Warning)] Variable "sortEmpty" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sortEmpty|
+//@[04:13) [no-unused-vars (Warning)] Variable "sortEmpty" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |sortEmpty|
 var reduceStringConcat = reduce(
-//@[4:22) [no-unused-vars (Warning)] Variable "reduceStringConcat" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduceStringConcat|
+//@[04:22) [no-unused-vars (Warning)] Variable "reduceStringConcat" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduceStringConcat|
   [
     'abc'
     'def'
@@ -139,11 +139,12 @@ var reduceStringConcat = reduce(
   ],
   '',
   (cur, next) => concat(cur, next)
+//@[17:34) [prefer-interpolation (Warning)] Use string interpolation instead of the concat function. (CodeDescription: bicep core(https://aka.ms/bicep/linter/prefer-interpolation)) |concat(cur, next)|
 )
 var reduceFactorial = reduce(range(1, 5), 1, (cur, next) => (cur * next))
-//@[4:19) [no-unused-vars (Warning)] Variable "reduceFactorial" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduceFactorial|
+//@[04:19) [no-unused-vars (Warning)] Variable "reduceFactorial" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduceFactorial|
 var reduceObjectUnion = reduce(
-//@[4:21) [no-unused-vars (Warning)] Variable "reduceObjectUnion" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduceObjectUnion|
+//@[04:21) [no-unused-vars (Warning)] Variable "reduceObjectUnion" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduceObjectUnion|
   [
     {
       foo: 123
@@ -159,37 +160,38 @@ var reduceObjectUnion = reduce(
   (cur, next) => union(cur, next)
 )
 var reduceEmpty = reduce([], 0, (cur, next) => cur)
-//@[4:15) [no-unused-vars (Warning)] Variable "reduceEmpty" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduceEmpty|
+//@[04:15) [no-unused-vars (Warning)] Variable "reduceEmpty" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |reduceEmpty|
 var filteredLoop = filter(itemForLoop, i => (i > 5))
-//@[4:16) [no-unused-vars (Warning)] Variable "filteredLoop" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |filteredLoop|
+//@[04:16) [no-unused-vars (Warning)] Variable "filteredLoop" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |filteredLoop|
 var parentheses = map(
-//@[4:15) [no-unused-vars (Warning)] Variable "parentheses" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |parentheses|
+//@[04:15) [no-unused-vars (Warning)] Variable "parentheses" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |parentheses|
   [
     123
   ],
   i => i
 )
 var objectMap = toObject(
-//@[4:13) [no-unused-vars (Warning)] Variable "objectMap" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectMap|
+//@[04:13) [no-unused-vars (Warning)] Variable "objectMap" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectMap|
   [
     123
     456
     789
   ],
   i => (i / 100)
-//@[2:16) [BCP070 (Error)] Argument of type "any => int" is not assignable to parameter of type "any => string". (CodeDescription: none) |i => (i / 100)|
+//@[02:16) [BCP070 (Error)] Argument of type "(123 | 456 | 789) => int" is not assignable to parameter of type "any => string". (CodeDescription: none) |i => (i / 100)|
 )
 var objectMap2 = toObject(
-//@[4:14) [no-unused-vars (Warning)] Variable "objectMap2" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectMap2|
+//@[04:14) [no-unused-vars (Warning)] Variable "objectMap2" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectMap2|
   range(0, 10),
   i => i,
+//@[02:08) [BCP070 (Error)] Argument of type "int => int" is not assignable to parameter of type "any => string". (CodeDescription: none) |i => i|
   i => {
     isEven: ((i % 2) == 0)
     isGreaterThan4: (i > 4)
   }
 )
 var objectMap3 = toObject(sortByObjectKey, x => x.name)
-//@[4:14) [no-unused-vars (Warning)] Variable "objectMap3" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectMap3|
+//@[04:14) [no-unused-vars (Warning)] Variable "objectMap3" is declared but never used. (CodeDescription: bicep core(https://aka.ms/bicep/linter/no-unused-vars)) |objectMap3|
 var itemForLoop = [for i in range(0, length(range(0, 10))): range(0, 10)[i]]
 
 module asdfsadf './nested_asdfsadf.bicep' = {