From af2ac818d4ca7851c72c3f1fdcf4a589adb7a003 Mon Sep 17 00:00:00 2001
From: "G.Reijn" <gijsreijn@hotmail.com>
Date: Fri, 26 Sep 2025 14:23:01 +0200
Subject: [PATCH 1/9] Add intersection() function

---
 dsc/tests/dsc_functions.tests.ps1     |  70 ++++++++++++
 dsc_lib/locales/en-us.toml            |   5 +
 dsc_lib/src/functions/intersection.rs | 155 ++++++++++++++++++++++++++
 dsc_lib/src/functions/mod.rs          |   2 +
 4 files changed, 232 insertions(+)
 create mode 100644 dsc_lib/src/functions/intersection.rs

diff --git a/dsc/tests/dsc_functions.tests.ps1 b/dsc/tests/dsc_functions.tests.ps1
index 6538c9c7e..b1583ebb2 100644
--- a/dsc/tests/dsc_functions.tests.ps1
+++ b/dsc/tests/dsc_functions.tests.ps1
@@ -111,6 +111,76 @@ Describe 'tests for function expressions' {
     }
   }
 
+  It 'intersection function works for: <expression>' -TestCases @(
+    @{ expression = "[intersection(parameters('firstArray'), parameters('secondArray'))]"; expected = @('cd') }
+    @{ expression = "[intersection(parameters('firstObject'), parameters('secondObject'))]"; expected = [pscustomobject]@{ two = 'b' } }
+    @{ expression = "[intersection(parameters('thirdArray'), parameters('fourthArray'))]"; expected = @('ef', 'gh') }
+    @{ expression = "[intersection(parameters('thirdObject'), parameters('fourthObject'))]"; expected = [pscustomobject]@{ three = 'd' } }
+    @{ expression = "[intersection(parameters('firstArray'), parameters('thirdArray'))]"; expected = @() }
+    @{ expression = "[intersection(parameters('firstObject'), parameters('firstArray'))]"; isError = $true }
+  ) {
+    param($expression, $expected, $isError)
+
+    $config_yaml = @"
+            `$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+            parameters:
+              firstObject:
+                type: object
+                defaultValue:
+                  one: a
+                  two: b
+              secondObject:
+                type: object
+                defaultValue:
+                  two: b
+                  three: d
+              thirdObject:
+                type: object
+                defaultValue:
+                  two: c
+                  three: d
+              fourthObject:
+                type: object
+                defaultValue:
+                  three: d
+                  four: e
+              firstArray:
+                type: array
+                defaultValue:
+                - ab
+                - cd
+              secondArray:
+                type: array
+                defaultValue:
+                - cd
+                - ef
+              thirdArray:
+                type: array
+                defaultValue:
+                - ef
+                - gh
+              fourthArray:
+                type: array
+                defaultValue:
+                - gh
+                - ef
+                - ij
+            resources:
+            - name: Echo
+              type: Microsoft.DSC.Debug/Echo
+              properties:
+                output: "$expression"
+"@
+    $out = dsc -l trace config get -i $config_yaml 2>$TestDrive/error.log | ConvertFrom-Json
+    if ($isError) {
+      $LASTEXITCODE | Should -Be 2 -Because (Get-Content $TestDrive/error.log -Raw)
+      (Get-Content $TestDrive/error.log -Raw) | Should -Match 'All arguments must either be arrays or objects'
+    } else {
+      $LASTEXITCODE | Should -Be 0 -Because (Get-Content $TestDrive/error.log -Raw)
+      ($out.results[0].result.actualState.output | Out-String) | Should -BeExactly ($expected | Out-String)
+    }
+  }
+
   It 'contain function works for: <expression>' -TestCases @(
     @{ expression = "[contains(parameters('array'), 'a')]" ; expected = $true }
     @{ expression = "[contains(parameters('array'), 2)]" ; expected = $false }
diff --git a/dsc_lib/locales/en-us.toml b/dsc_lib/locales/en-us.toml
index ada29a34c..8f0d903de 100644
--- a/dsc_lib/locales/en-us.toml
+++ b/dsc_lib/locales/en-us.toml
@@ -353,6 +353,11 @@ parseStringError = "unable to parse string to int"
 castError = "unable to cast to int"
 parseNumError = "unable to parse number to int"
 
+[functions.intersection]
+description = "Returns a single array or object with the common elements from the parameters"
+invoked = "intersection function"
+invalidArgType = "All arguments must either be arrays or objects"
+
 [functions.indexOf]
 description = "Returns the index of the first occurrence of an item in an array"
 invoked = "indexOf function"
diff --git a/dsc_lib/src/functions/intersection.rs b/dsc_lib/src/functions/intersection.rs
new file mode 100644
index 000000000..f8ceceaf1
--- /dev/null
+++ b/dsc_lib/src/functions/intersection.rs
@@ -0,0 +1,155 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+use crate::DscError;
+use crate::configure::context::Context;
+use crate::functions::{FunctionArgKind, Function, FunctionCategory, FunctionMetadata};
+use rust_i18n::t;
+use serde_json::{Map, Value};
+use tracing::debug;
+
+#[derive(Debug, Default)]
+pub struct Intersection {}
+
+impl Function for Intersection {
+    fn get_metadata(&self) -> FunctionMetadata {
+        FunctionMetadata {
+            name: "intersection".to_string(),
+            description: t!("functions.intersection.description").to_string(),
+            category: FunctionCategory::Array,
+            min_args: 2,
+            max_args: usize::MAX,
+            accepted_arg_ordered_types: vec![
+                vec![FunctionArgKind::Array, FunctionArgKind::Object],
+                vec![FunctionArgKind::Array, FunctionArgKind::Object],
+            ],
+            remaining_arg_accepted_types: Some(vec![FunctionArgKind::Array, FunctionArgKind::Object]),
+            return_types: vec![FunctionArgKind::Array, FunctionArgKind::Object],
+        }
+    }
+
+    fn invoke(&self, args: &[Value], _context: &Context) -> Result<Value, DscError> {
+        debug!("{}", t!("functions.intersection.invoked"));
+        
+        if args[0].is_array() {
+            let first_array = args[0].as_array().unwrap();
+            let mut result = Vec::new();
+            
+            for item in first_array {
+                let mut found_in_all = true;
+                
+                for arg in &args[1..] {
+                    if let Some(array) = arg.as_array() {
+                        if !array.contains(item) {
+                            found_in_all = false;
+                            break;
+                        }
+                    } else {
+                        return Err(DscError::Parser(t!("functions.intersection.invalidArgType").to_string()));
+                    }
+                }
+                
+                if found_in_all && !result.contains(item) {
+                    result.push(item.clone());
+                }
+            }
+            
+            return Ok(Value::Array(result));
+        }
+
+        if args[0].is_object() {
+            let first_object = args[0].as_object().unwrap();
+            let mut result = Map::new();
+            
+            for (key, value) in first_object {
+                let mut found_in_all = true;
+                
+                for arg in &args[1..] {
+                    if let Some(object) = arg.as_object() {
+                        if let Some(other_value) = object.get(key) {
+                            if other_value != value {
+                                found_in_all = false;
+                                break;
+                            }
+                        } else {
+                            found_in_all = false;
+                            break;
+                        }
+                    } else {
+                        return Err(DscError::Parser(t!("functions.intersection.invalidArgType").to_string()));
+                    }
+                }
+                
+                if found_in_all {
+                    result.insert(key.clone(), value.clone());
+                }
+            }
+            
+            return Ok(Value::Object(result));
+        }
+
+        Err(DscError::Parser(t!("functions.intersection.invalidArgType").to_string()))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::configure::context::Context;
+    use crate::parser::Statement;
+
+    #[test]
+    fn array_intersection() {
+        let mut parser = Statement::new().unwrap();
+        let result = parser.parse_and_execute("[intersection(createArray(1, 2, 3), createArray(2, 3, 4))]", &Context::new()).unwrap();
+        assert_eq!(result, serde_json::json!([2, 3]));
+    }
+
+    #[test]
+    fn array_intersection_three_arrays() {
+        let mut parser = Statement::new().unwrap();
+        let result = parser.parse_and_execute("[intersection(createArray(1, 2, 3, 4), createArray(2, 3, 4, 5), createArray(3, 4, 5, 6))]", &Context::new()).unwrap();
+        assert_eq!(result, serde_json::json!([3, 4]));
+    }
+
+    #[test]
+    fn array_intersection_no_common_elements() {
+        let mut parser = Statement::new().unwrap();
+        let result = parser.parse_and_execute("[intersection(createArray(1, 2), createArray(3, 4))]", &Context::new()).unwrap();
+        assert_eq!(result, serde_json::json!([]));
+    }
+
+    #[test]
+    fn array_intersection_with_duplicates() {
+        let mut parser = Statement::new().unwrap();
+        let result = parser.parse_and_execute("[intersection(createArray(1, 2, 2, 3), createArray(2, 2, 3, 4))]", &Context::new()).unwrap();
+        assert_eq!(result, serde_json::json!([2, 3]));
+    }
+
+    #[test]
+    fn object_intersection() {
+        let mut parser = Statement::new().unwrap();
+        let result = parser.parse_and_execute("[intersection(createObject('a', 1, 'b', 2), createObject('b', 2, 'c', 3))]", &Context::new()).unwrap();
+        assert_eq!(result, serde_json::json!({"b": 2}));
+    }
+
+    #[test]
+    fn object_intersection_different_values() {
+        let mut parser = Statement::new().unwrap();
+        let result = parser.parse_and_execute("[intersection(createObject('a', 1, 'b', 2), createObject('a', 2, 'b', 2))]", &Context::new()).unwrap();
+        assert_eq!(result, serde_json::json!({"b": 2}));
+    }
+
+    #[test]
+    fn object_intersection_no_common_keys() {
+        let mut parser = Statement::new().unwrap();
+        let result = parser.parse_and_execute("[intersection(createObject('a', 1), createObject('b', 2))]", &Context::new()).unwrap();
+        assert_eq!(result, serde_json::json!({}));
+    }
+
+    #[test]
+    fn mixed_types_error() {
+        let mut parser = Statement::new().unwrap();
+        let result = parser.parse_and_execute("[intersection(createArray(1, 2), createObject('a', 1))]", &Context::new());
+        assert!(result.is_err());
+    }
+}
\ No newline at end of file
diff --git a/dsc_lib/src/functions/mod.rs b/dsc_lib/src/functions/mod.rs
index e881acc3e..a28395eef 100644
--- a/dsc_lib/src/functions/mod.rs
+++ b/dsc_lib/src/functions/mod.rs
@@ -40,6 +40,7 @@ pub mod less_or_equals;
 pub mod format;
 pub mod int;
 pub mod index_of;
+pub mod intersection;
 pub mod join;
 pub mod last_index_of;
 pub mod max;
@@ -155,6 +156,7 @@ impl FunctionDispatcher {
             Box::new(format::Format{}),
             Box::new(int::Int{}),
             Box::new(index_of::IndexOf{}),
+            Box::new(intersection::Intersection{}),
             Box::new(join::Join{}),
             Box::new(last_index_of::LastIndexOf{}),
             Box::new(max::Max{}),

From d5c3f86b781178049929f0a21182fba4715b70d8 Mon Sep 17 00:00:00 2001
From: "G.Reijn" <gijsreijn@hotmail.com>
Date: Fri, 26 Sep 2025 14:27:39 +0200
Subject: [PATCH 2/9] Add documentation

---
 .../schemas/config/functions/intersection.md  | 236 ++++++++++++++++++
 1 file changed, 236 insertions(+)
 create mode 100644 docs/reference/schemas/config/functions/intersection.md

diff --git a/docs/reference/schemas/config/functions/intersection.md b/docs/reference/schemas/config/functions/intersection.md
new file mode 100644
index 000000000..5e2066772
--- /dev/null
+++ b/docs/reference/schemas/config/functions/intersection.md
@@ -0,0 +1,236 @@
+---
+description: Reference for the 'intersection' DSC configuration document function
+ms.date:     09/26/2025
+ms.topic:    reference
+title:       intersection
+---
+
+## Synopsis
+
+Returns a single array or object with the common elements from the parameters.
+
+## Syntax
+
+```Syntax
+intersection(value1, value2, ...)
+```
+
+## Description
+
+The `intersection()` function takes two or more arrays or objects and returns
+only the elements that exist in all of them. For arrays, it returns elements
+that appear in every array. For objects, it returns key-value pairs where both
+the key and value match across all objects.
+
+All parameters must be the same type - either all arrays or all objects.
+Results are deduplicated, meaning each element appears only once in the output.
+
+Supported types:
+
+- Arrays (elements compared by value)
+- Objects (key-value pairs compared by deep equality)
+
+## Examples
+
+### Example 1 - Find common security groups across environments (arrays)
+
+Use `intersection()` to identify security groups that are consistently applied
+across development, staging, and production environments. This helps ensure
+security policies are uniformly enforced. This example uses
+[`createArray()`][01] to build the security group lists.
+
+```yaml
+# intersection.example.1.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+resources:
+- name: Common Security Groups
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      commonGroups: "[intersection(createArray('admin-access', 'monitoring', 'backup'), createArray('monitoring', 'backup', 'web-access'), createArray('backup', 'monitoring', 'database'))]"
+      twoEnvCommon: "[intersection(createArray('admin-access', 'monitoring'), createArray('monitoring', 'audit-log'))]"
+```
+
+```bash
+dsc config get --file intersection.example.1.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Common Security Groups
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        commonGroups:
+        - monitoring
+        - backup
+        twoEnvCommon:
+        - monitoring
+messages: []
+hadErrors: false
+```
+
+### Example 2 - Identify shared configuration properties (objects)
+
+Find configuration settings that are identical across multiple service
+instances. This is useful for extracting common configuration into shared
+templates or validating consistency. This example uses [`createObject()`][02]
+to build configuration objects.
+
+```yaml
+# intersection.example.2.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+resources:
+- name: Shared Config Properties
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      commonSettings: "[intersection(createObject('timeout', 30, 'retries', 3, 'region', 'us-east'), createObject('retries', 3, 'ssl', true, 'region', 'us-east'), createObject('region', 'us-east', 'retries', 3, 'logging', 'info'))]"
+```
+
+```bash
+dsc config get --file intersection.example.2.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Shared Config Properties
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        commonSettings:
+          region: us-east
+          retries: 3
+messages: []
+hadErrors: false
+```
+
+### Example 3 - Find overlapping server capabilities (arrays with no matches)
+
+Sometimes environments have no common elements, which is valuable information
+for infrastructure planning. This example shows how `intersection()` handles
+arrays with no shared elements.
+
+```yaml
+# intersection.example.3.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+resources:
+- name: Server Capabilities
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      noOverlap: "[intersection(createArray('windows-iis', 'dotnet-core'), createArray('linux-apache', 'php', 'mysql'))]"
+      someOverlap: "[intersection(createArray('docker', 'kubernetes', 'monitoring'), createArray('monitoring', 'logging', 'docker'))]"
+```
+
+```bash
+dsc config get --file intersection.example.3.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Server Capabilities
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        noOverlap: []
+        someOverlap:
+        - docker
+        - monitoring
+messages: []
+hadErrors: false
+```
+
+### Example 4 - Validate compliance across teams (objects)
+
+Use `intersection()` to verify that critical compliance settings are identical
+across different team configurations. Only settings with matching values will
+appear in the result.
+
+```yaml
+# intersection.example.4.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+resources:
+- name: Compliance Check
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      sharedCompliance: "[intersection(createObject('encryption', true, 'backup', 'daily', 'audit', true), createObject('audit', true, 'encryption', true, 'access', 'restricted'), createObject('encryption', true, 'audit', true, 'monitoring', 'enabled'))]"
+```
+
+```bash
+dsc config get --file intersection.example.4.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Compliance Check
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        sharedCompliance:
+          audit: true
+          encryption: true
+messages: []
+hadErrors: false
+```
+
+## Parameters
+
+### value1
+
+The first array or object to compare. Required.
+
+```yaml
+Type:     array | object
+Required: true
+Position: 1
+```
+
+### value2
+
+The second array or object to compare. Must be the same type as value1.
+Required.
+
+```yaml
+Type:     array | object
+Required: true
+Position: 2
+```
+
+### Additional values
+
+Additional arrays or objects to include in the intersection. All must be the
+same type. Optional.
+
+```yaml
+Type:     array | object
+Required: false
+Position: 3+
+```
+
+## Output
+
+Returns an array or object containing only the common elements. The return type
+matches the input type.
+
+```yaml
+Type: array | object
+```
+
+## Related functions
+
+- [`union()`][00] - Combines all elements from multiple arrays or objects
+- [`contains()`][03] - Checks for presence in arrays/objects/strings
+- [`createArray()`][01] - Creates an array from individual values
+- [`createObject()`][02] - Creates an object from key-value pairs
+
+<!-- Link reference definitions -->
+[00]: ./union.md
+[01]: ./createArray.md
+[02]: ./createObject.md
+[03]: ./contains.md

From 2caf08e1730d6bc751758e3790e724a4e48ef220 Mon Sep 17 00:00:00 2001
From: "G.Reijn" <gijsreijn@hotmail.com>
Date: Sat, 27 Sep 2025 01:49:44 +0200
Subject: [PATCH 3/9] Resolve remarks

---
 dsc/tests/dsc_functions.tests.ps1     | 54 +++++++++++++++++++++++++++
 dsc_lib/src/functions/intersection.rs |  6 +--
 2 files changed, 56 insertions(+), 4 deletions(-)

diff --git a/dsc/tests/dsc_functions.tests.ps1 b/dsc/tests/dsc_functions.tests.ps1
index b1583ebb2..7b3dce608 100644
--- a/dsc/tests/dsc_functions.tests.ps1
+++ b/dsc/tests/dsc_functions.tests.ps1
@@ -118,6 +118,19 @@ Describe 'tests for function expressions' {
     @{ expression = "[intersection(parameters('thirdObject'), parameters('fourthObject'))]"; expected = [pscustomobject]@{ three = 'd' } }
     @{ expression = "[intersection(parameters('firstArray'), parameters('thirdArray'))]"; expected = @() }
     @{ expression = "[intersection(parameters('firstObject'), parameters('firstArray'))]"; isError = $true }
+    # Test with 3 arrays - should find common elements across all three
+    @{ expression = "[intersection(parameters('firstArray'), parameters('secondArray'), parameters('fifthArray'))]"; expected = @('cd') }
+    # Test with 3 objects - should find properties with matching key-value pairs across all three
+    @{ expression = "[intersection(parameters('firstObject'), parameters('secondObject'), parameters('sixthObject'))]"; expected = [pscustomobject]@{ two = 'b' } }
+    # Test with nested objects - should match deep equality
+    @{ expression = "[intersection(parameters('nestedObject1'), parameters('nestedObject2'))]"; expected = [pscustomobject]@{ 
+      shared = [pscustomobject]@{ value = 42; flag = $true }
+      level = 1
+    } }
+    # Test with nested objects - no common nested properties
+    @{ expression = "[intersection(parameters('nestedObject1'), parameters('nestedObject3'))]"; expected = [pscustomobject]@{ level = 1 } }
+    # Test with 3 nested objects
+    @{ expression = "[intersection(parameters('nestedObject1'), parameters('nestedObject2'), parameters('nestedObject4'))]"; expected = [pscustomobject]@{ level = 1 } }
   ) {
     param($expression, $expected, $isError)
 
@@ -144,6 +157,42 @@ Describe 'tests for function expressions' {
                 defaultValue:
                   three: d
                   four: e
+              sixthObject:
+                type: object
+                defaultValue:
+                  two: b
+                  five: f
+              nestedObject1:
+                type: object
+                defaultValue:
+                  shared:
+                    value: 42
+                    flag: true
+                  level: 1
+                  unique1: test
+              nestedObject2:
+                type: object
+                defaultValue:
+                  shared:
+                    value: 42
+                    flag: true
+                  level: 1
+                  unique2: test
+              nestedObject3:
+                type: object
+                defaultValue:
+                  shared:
+                    value: 24
+                    flag: true
+                  level: 1
+                  unique3: test
+              nestedObject4:
+                type: object
+                defaultValue:
+                  level: 1
+                  different:
+                    value: 100
+                    flag: false
               firstArray:
                 type: array
                 defaultValue:
@@ -165,6 +214,11 @@ Describe 'tests for function expressions' {
                 - gh
                 - ef
                 - ij
+              fifthArray:
+                type: array
+                defaultValue:
+                - cd
+                - kl
             resources:
             - name: Echo
               type: Microsoft.DSC.Debug/Echo
diff --git a/dsc_lib/src/functions/intersection.rs b/dsc_lib/src/functions/intersection.rs
index f8ceceaf1..6c0dd4a9a 100644
--- a/dsc_lib/src/functions/intersection.rs
+++ b/dsc_lib/src/functions/intersection.rs
@@ -31,8 +31,7 @@ impl Function for Intersection {
     fn invoke(&self, args: &[Value], _context: &Context) -> Result<Value, DscError> {
         debug!("{}", t!("functions.intersection.invoked"));
         
-        if args[0].is_array() {
-            let first_array = args[0].as_array().unwrap();
+        if let Some(first_array) = args[0].as_array() {
             let mut result = Vec::new();
             
             for item in first_array {
@@ -57,8 +56,7 @@ impl Function for Intersection {
             return Ok(Value::Array(result));
         }
 
-        if args[0].is_object() {
-            let first_object = args[0].as_object().unwrap();
+        if let Some(first_object) = args[0].as_object() {
             let mut result = Map::new();
             
             for (key, value) in first_object {

From 4ce01ed45c756aa7faa4b44e522c2cd73fcf1d31 Mon Sep 17 00:00:00 2001
From: "G.Reijn" <gijsreijn@hotmail.com>
Date: Sat, 27 Sep 2025 01:50:29 +0200
Subject: [PATCH 4/9] Remove comments

---
 dsc/tests/dsc_functions.tests.ps1 | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/dsc/tests/dsc_functions.tests.ps1 b/dsc/tests/dsc_functions.tests.ps1
index 7b3dce608..75d193002 100644
--- a/dsc/tests/dsc_functions.tests.ps1
+++ b/dsc/tests/dsc_functions.tests.ps1
@@ -118,18 +118,13 @@ Describe 'tests for function expressions' {
     @{ expression = "[intersection(parameters('thirdObject'), parameters('fourthObject'))]"; expected = [pscustomobject]@{ three = 'd' } }
     @{ expression = "[intersection(parameters('firstArray'), parameters('thirdArray'))]"; expected = @() }
     @{ expression = "[intersection(parameters('firstObject'), parameters('firstArray'))]"; isError = $true }
-    # Test with 3 arrays - should find common elements across all three
     @{ expression = "[intersection(parameters('firstArray'), parameters('secondArray'), parameters('fifthArray'))]"; expected = @('cd') }
-    # Test with 3 objects - should find properties with matching key-value pairs across all three
     @{ expression = "[intersection(parameters('firstObject'), parameters('secondObject'), parameters('sixthObject'))]"; expected = [pscustomobject]@{ two = 'b' } }
-    # Test with nested objects - should match deep equality
     @{ expression = "[intersection(parameters('nestedObject1'), parameters('nestedObject2'))]"; expected = [pscustomobject]@{ 
       shared = [pscustomobject]@{ value = 42; flag = $true }
       level = 1
     } }
-    # Test with nested objects - no common nested properties
     @{ expression = "[intersection(parameters('nestedObject1'), parameters('nestedObject3'))]"; expected = [pscustomobject]@{ level = 1 } }
-    # Test with 3 nested objects
     @{ expression = "[intersection(parameters('nestedObject1'), parameters('nestedObject2'), parameters('nestedObject4'))]"; expected = [pscustomobject]@{ level = 1 } }
   ) {
     param($expression, $expected, $isError)

From 9d70166acfac59366fbbde471749fc442120ff40 Mon Sep 17 00:00:00 2001
From: "G.Reijn" <gijsreijn@hotmail.com>
Date: Fri, 26 Sep 2025 14:23:01 +0200
Subject: [PATCH 5/9] Add intersection() function

---
 dsc/tests/dsc_functions.tests.ps1     |  70 ++++++++++++
 dsc_lib/locales/en-us.toml            |   5 +
 dsc_lib/src/functions/intersection.rs | 155 ++++++++++++++++++++++++++
 dsc_lib/src/functions/mod.rs          |   2 +
 4 files changed, 232 insertions(+)
 create mode 100644 dsc_lib/src/functions/intersection.rs

diff --git a/dsc/tests/dsc_functions.tests.ps1 b/dsc/tests/dsc_functions.tests.ps1
index 6538c9c7e..b1583ebb2 100644
--- a/dsc/tests/dsc_functions.tests.ps1
+++ b/dsc/tests/dsc_functions.tests.ps1
@@ -111,6 +111,76 @@ Describe 'tests for function expressions' {
     }
   }
 
+  It 'intersection function works for: <expression>' -TestCases @(
+    @{ expression = "[intersection(parameters('firstArray'), parameters('secondArray'))]"; expected = @('cd') }
+    @{ expression = "[intersection(parameters('firstObject'), parameters('secondObject'))]"; expected = [pscustomobject]@{ two = 'b' } }
+    @{ expression = "[intersection(parameters('thirdArray'), parameters('fourthArray'))]"; expected = @('ef', 'gh') }
+    @{ expression = "[intersection(parameters('thirdObject'), parameters('fourthObject'))]"; expected = [pscustomobject]@{ three = 'd' } }
+    @{ expression = "[intersection(parameters('firstArray'), parameters('thirdArray'))]"; expected = @() }
+    @{ expression = "[intersection(parameters('firstObject'), parameters('firstArray'))]"; isError = $true }
+  ) {
+    param($expression, $expected, $isError)
+
+    $config_yaml = @"
+            `$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+            parameters:
+              firstObject:
+                type: object
+                defaultValue:
+                  one: a
+                  two: b
+              secondObject:
+                type: object
+                defaultValue:
+                  two: b
+                  three: d
+              thirdObject:
+                type: object
+                defaultValue:
+                  two: c
+                  three: d
+              fourthObject:
+                type: object
+                defaultValue:
+                  three: d
+                  four: e
+              firstArray:
+                type: array
+                defaultValue:
+                - ab
+                - cd
+              secondArray:
+                type: array
+                defaultValue:
+                - cd
+                - ef
+              thirdArray:
+                type: array
+                defaultValue:
+                - ef
+                - gh
+              fourthArray:
+                type: array
+                defaultValue:
+                - gh
+                - ef
+                - ij
+            resources:
+            - name: Echo
+              type: Microsoft.DSC.Debug/Echo
+              properties:
+                output: "$expression"
+"@
+    $out = dsc -l trace config get -i $config_yaml 2>$TestDrive/error.log | ConvertFrom-Json
+    if ($isError) {
+      $LASTEXITCODE | Should -Be 2 -Because (Get-Content $TestDrive/error.log -Raw)
+      (Get-Content $TestDrive/error.log -Raw) | Should -Match 'All arguments must either be arrays or objects'
+    } else {
+      $LASTEXITCODE | Should -Be 0 -Because (Get-Content $TestDrive/error.log -Raw)
+      ($out.results[0].result.actualState.output | Out-String) | Should -BeExactly ($expected | Out-String)
+    }
+  }
+
   It 'contain function works for: <expression>' -TestCases @(
     @{ expression = "[contains(parameters('array'), 'a')]" ; expected = $true }
     @{ expression = "[contains(parameters('array'), 2)]" ; expected = $false }
diff --git a/dsc_lib/locales/en-us.toml b/dsc_lib/locales/en-us.toml
index ada29a34c..8f0d903de 100644
--- a/dsc_lib/locales/en-us.toml
+++ b/dsc_lib/locales/en-us.toml
@@ -353,6 +353,11 @@ parseStringError = "unable to parse string to int"
 castError = "unable to cast to int"
 parseNumError = "unable to parse number to int"
 
+[functions.intersection]
+description = "Returns a single array or object with the common elements from the parameters"
+invoked = "intersection function"
+invalidArgType = "All arguments must either be arrays or objects"
+
 [functions.indexOf]
 description = "Returns the index of the first occurrence of an item in an array"
 invoked = "indexOf function"
diff --git a/dsc_lib/src/functions/intersection.rs b/dsc_lib/src/functions/intersection.rs
new file mode 100644
index 000000000..f8ceceaf1
--- /dev/null
+++ b/dsc_lib/src/functions/intersection.rs
@@ -0,0 +1,155 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+use crate::DscError;
+use crate::configure::context::Context;
+use crate::functions::{FunctionArgKind, Function, FunctionCategory, FunctionMetadata};
+use rust_i18n::t;
+use serde_json::{Map, Value};
+use tracing::debug;
+
+#[derive(Debug, Default)]
+pub struct Intersection {}
+
+impl Function for Intersection {
+    fn get_metadata(&self) -> FunctionMetadata {
+        FunctionMetadata {
+            name: "intersection".to_string(),
+            description: t!("functions.intersection.description").to_string(),
+            category: FunctionCategory::Array,
+            min_args: 2,
+            max_args: usize::MAX,
+            accepted_arg_ordered_types: vec![
+                vec![FunctionArgKind::Array, FunctionArgKind::Object],
+                vec![FunctionArgKind::Array, FunctionArgKind::Object],
+            ],
+            remaining_arg_accepted_types: Some(vec![FunctionArgKind::Array, FunctionArgKind::Object]),
+            return_types: vec![FunctionArgKind::Array, FunctionArgKind::Object],
+        }
+    }
+
+    fn invoke(&self, args: &[Value], _context: &Context) -> Result<Value, DscError> {
+        debug!("{}", t!("functions.intersection.invoked"));
+        
+        if args[0].is_array() {
+            let first_array = args[0].as_array().unwrap();
+            let mut result = Vec::new();
+            
+            for item in first_array {
+                let mut found_in_all = true;
+                
+                for arg in &args[1..] {
+                    if let Some(array) = arg.as_array() {
+                        if !array.contains(item) {
+                            found_in_all = false;
+                            break;
+                        }
+                    } else {
+                        return Err(DscError::Parser(t!("functions.intersection.invalidArgType").to_string()));
+                    }
+                }
+                
+                if found_in_all && !result.contains(item) {
+                    result.push(item.clone());
+                }
+            }
+            
+            return Ok(Value::Array(result));
+        }
+
+        if args[0].is_object() {
+            let first_object = args[0].as_object().unwrap();
+            let mut result = Map::new();
+            
+            for (key, value) in first_object {
+                let mut found_in_all = true;
+                
+                for arg in &args[1..] {
+                    if let Some(object) = arg.as_object() {
+                        if let Some(other_value) = object.get(key) {
+                            if other_value != value {
+                                found_in_all = false;
+                                break;
+                            }
+                        } else {
+                            found_in_all = false;
+                            break;
+                        }
+                    } else {
+                        return Err(DscError::Parser(t!("functions.intersection.invalidArgType").to_string()));
+                    }
+                }
+                
+                if found_in_all {
+                    result.insert(key.clone(), value.clone());
+                }
+            }
+            
+            return Ok(Value::Object(result));
+        }
+
+        Err(DscError::Parser(t!("functions.intersection.invalidArgType").to_string()))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::configure::context::Context;
+    use crate::parser::Statement;
+
+    #[test]
+    fn array_intersection() {
+        let mut parser = Statement::new().unwrap();
+        let result = parser.parse_and_execute("[intersection(createArray(1, 2, 3), createArray(2, 3, 4))]", &Context::new()).unwrap();
+        assert_eq!(result, serde_json::json!([2, 3]));
+    }
+
+    #[test]
+    fn array_intersection_three_arrays() {
+        let mut parser = Statement::new().unwrap();
+        let result = parser.parse_and_execute("[intersection(createArray(1, 2, 3, 4), createArray(2, 3, 4, 5), createArray(3, 4, 5, 6))]", &Context::new()).unwrap();
+        assert_eq!(result, serde_json::json!([3, 4]));
+    }
+
+    #[test]
+    fn array_intersection_no_common_elements() {
+        let mut parser = Statement::new().unwrap();
+        let result = parser.parse_and_execute("[intersection(createArray(1, 2), createArray(3, 4))]", &Context::new()).unwrap();
+        assert_eq!(result, serde_json::json!([]));
+    }
+
+    #[test]
+    fn array_intersection_with_duplicates() {
+        let mut parser = Statement::new().unwrap();
+        let result = parser.parse_and_execute("[intersection(createArray(1, 2, 2, 3), createArray(2, 2, 3, 4))]", &Context::new()).unwrap();
+        assert_eq!(result, serde_json::json!([2, 3]));
+    }
+
+    #[test]
+    fn object_intersection() {
+        let mut parser = Statement::new().unwrap();
+        let result = parser.parse_and_execute("[intersection(createObject('a', 1, 'b', 2), createObject('b', 2, 'c', 3))]", &Context::new()).unwrap();
+        assert_eq!(result, serde_json::json!({"b": 2}));
+    }
+
+    #[test]
+    fn object_intersection_different_values() {
+        let mut parser = Statement::new().unwrap();
+        let result = parser.parse_and_execute("[intersection(createObject('a', 1, 'b', 2), createObject('a', 2, 'b', 2))]", &Context::new()).unwrap();
+        assert_eq!(result, serde_json::json!({"b": 2}));
+    }
+
+    #[test]
+    fn object_intersection_no_common_keys() {
+        let mut parser = Statement::new().unwrap();
+        let result = parser.parse_and_execute("[intersection(createObject('a', 1), createObject('b', 2))]", &Context::new()).unwrap();
+        assert_eq!(result, serde_json::json!({}));
+    }
+
+    #[test]
+    fn mixed_types_error() {
+        let mut parser = Statement::new().unwrap();
+        let result = parser.parse_and_execute("[intersection(createArray(1, 2), createObject('a', 1))]", &Context::new());
+        assert!(result.is_err());
+    }
+}
\ No newline at end of file
diff --git a/dsc_lib/src/functions/mod.rs b/dsc_lib/src/functions/mod.rs
index 413d49e4d..d16c1d5ce 100644
--- a/dsc_lib/src/functions/mod.rs
+++ b/dsc_lib/src/functions/mod.rs
@@ -40,6 +40,7 @@ pub mod less_or_equals;
 pub mod format;
 pub mod int;
 pub mod index_of;
+pub mod intersection;
 pub mod join;
 pub mod last_index_of;
 pub mod max;
@@ -155,6 +156,7 @@ impl FunctionDispatcher {
             Box::new(format::Format{}),
             Box::new(int::Int{}),
             Box::new(index_of::IndexOf{}),
+            Box::new(intersection::Intersection{}),
             Box::new(join::Join{}),
             Box::new(last_index_of::LastIndexOf{}),
             Box::new(max::Max{}),

From ba7b614a394b5c315b56a469216e7eace8f99ae5 Mon Sep 17 00:00:00 2001
From: "G.Reijn" <gijsreijn@hotmail.com>
Date: Fri, 26 Sep 2025 14:27:39 +0200
Subject: [PATCH 6/9] Add documentation

---
 .../schemas/config/functions/intersection.md  | 236 ++++++++++++++++++
 1 file changed, 236 insertions(+)
 create mode 100644 docs/reference/schemas/config/functions/intersection.md

diff --git a/docs/reference/schemas/config/functions/intersection.md b/docs/reference/schemas/config/functions/intersection.md
new file mode 100644
index 000000000..5e2066772
--- /dev/null
+++ b/docs/reference/schemas/config/functions/intersection.md
@@ -0,0 +1,236 @@
+---
+description: Reference for the 'intersection' DSC configuration document function
+ms.date:     09/26/2025
+ms.topic:    reference
+title:       intersection
+---
+
+## Synopsis
+
+Returns a single array or object with the common elements from the parameters.
+
+## Syntax
+
+```Syntax
+intersection(value1, value2, ...)
+```
+
+## Description
+
+The `intersection()` function takes two or more arrays or objects and returns
+only the elements that exist in all of them. For arrays, it returns elements
+that appear in every array. For objects, it returns key-value pairs where both
+the key and value match across all objects.
+
+All parameters must be the same type - either all arrays or all objects.
+Results are deduplicated, meaning each element appears only once in the output.
+
+Supported types:
+
+- Arrays (elements compared by value)
+- Objects (key-value pairs compared by deep equality)
+
+## Examples
+
+### Example 1 - Find common security groups across environments (arrays)
+
+Use `intersection()` to identify security groups that are consistently applied
+across development, staging, and production environments. This helps ensure
+security policies are uniformly enforced. This example uses
+[`createArray()`][01] to build the security group lists.
+
+```yaml
+# intersection.example.1.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+resources:
+- name: Common Security Groups
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      commonGroups: "[intersection(createArray('admin-access', 'monitoring', 'backup'), createArray('monitoring', 'backup', 'web-access'), createArray('backup', 'monitoring', 'database'))]"
+      twoEnvCommon: "[intersection(createArray('admin-access', 'monitoring'), createArray('monitoring', 'audit-log'))]"
+```
+
+```bash
+dsc config get --file intersection.example.1.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Common Security Groups
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        commonGroups:
+        - monitoring
+        - backup
+        twoEnvCommon:
+        - monitoring
+messages: []
+hadErrors: false
+```
+
+### Example 2 - Identify shared configuration properties (objects)
+
+Find configuration settings that are identical across multiple service
+instances. This is useful for extracting common configuration into shared
+templates or validating consistency. This example uses [`createObject()`][02]
+to build configuration objects.
+
+```yaml
+# intersection.example.2.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+resources:
+- name: Shared Config Properties
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      commonSettings: "[intersection(createObject('timeout', 30, 'retries', 3, 'region', 'us-east'), createObject('retries', 3, 'ssl', true, 'region', 'us-east'), createObject('region', 'us-east', 'retries', 3, 'logging', 'info'))]"
+```
+
+```bash
+dsc config get --file intersection.example.2.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Shared Config Properties
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        commonSettings:
+          region: us-east
+          retries: 3
+messages: []
+hadErrors: false
+```
+
+### Example 3 - Find overlapping server capabilities (arrays with no matches)
+
+Sometimes environments have no common elements, which is valuable information
+for infrastructure planning. This example shows how `intersection()` handles
+arrays with no shared elements.
+
+```yaml
+# intersection.example.3.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+resources:
+- name: Server Capabilities
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      noOverlap: "[intersection(createArray('windows-iis', 'dotnet-core'), createArray('linux-apache', 'php', 'mysql'))]"
+      someOverlap: "[intersection(createArray('docker', 'kubernetes', 'monitoring'), createArray('monitoring', 'logging', 'docker'))]"
+```
+
+```bash
+dsc config get --file intersection.example.3.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Server Capabilities
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        noOverlap: []
+        someOverlap:
+        - docker
+        - monitoring
+messages: []
+hadErrors: false
+```
+
+### Example 4 - Validate compliance across teams (objects)
+
+Use `intersection()` to verify that critical compliance settings are identical
+across different team configurations. Only settings with matching values will
+appear in the result.
+
+```yaml
+# intersection.example.4.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+resources:
+- name: Compliance Check
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      sharedCompliance: "[intersection(createObject('encryption', true, 'backup', 'daily', 'audit', true), createObject('audit', true, 'encryption', true, 'access', 'restricted'), createObject('encryption', true, 'audit', true, 'monitoring', 'enabled'))]"
+```
+
+```bash
+dsc config get --file intersection.example.4.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Compliance Check
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        sharedCompliance:
+          audit: true
+          encryption: true
+messages: []
+hadErrors: false
+```
+
+## Parameters
+
+### value1
+
+The first array or object to compare. Required.
+
+```yaml
+Type:     array | object
+Required: true
+Position: 1
+```
+
+### value2
+
+The second array or object to compare. Must be the same type as value1.
+Required.
+
+```yaml
+Type:     array | object
+Required: true
+Position: 2
+```
+
+### Additional values
+
+Additional arrays or objects to include in the intersection. All must be the
+same type. Optional.
+
+```yaml
+Type:     array | object
+Required: false
+Position: 3+
+```
+
+## Output
+
+Returns an array or object containing only the common elements. The return type
+matches the input type.
+
+```yaml
+Type: array | object
+```
+
+## Related functions
+
+- [`union()`][00] - Combines all elements from multiple arrays or objects
+- [`contains()`][03] - Checks for presence in arrays/objects/strings
+- [`createArray()`][01] - Creates an array from individual values
+- [`createObject()`][02] - Creates an object from key-value pairs
+
+<!-- Link reference definitions -->
+[00]: ./union.md
+[01]: ./createArray.md
+[02]: ./createObject.md
+[03]: ./contains.md

From 1401cabcc7ee46df6d4c62d4efc69e5392ede031 Mon Sep 17 00:00:00 2001
From: "G.Reijn" <gijsreijn@hotmail.com>
Date: Sat, 27 Sep 2025 01:49:44 +0200
Subject: [PATCH 7/9] Resolve remarks

---
 dsc/tests/dsc_functions.tests.ps1     | 54 +++++++++++++++++++++++++++
 dsc_lib/src/functions/intersection.rs |  6 +--
 2 files changed, 56 insertions(+), 4 deletions(-)

diff --git a/dsc/tests/dsc_functions.tests.ps1 b/dsc/tests/dsc_functions.tests.ps1
index b1583ebb2..7b3dce608 100644
--- a/dsc/tests/dsc_functions.tests.ps1
+++ b/dsc/tests/dsc_functions.tests.ps1
@@ -118,6 +118,19 @@ Describe 'tests for function expressions' {
     @{ expression = "[intersection(parameters('thirdObject'), parameters('fourthObject'))]"; expected = [pscustomobject]@{ three = 'd' } }
     @{ expression = "[intersection(parameters('firstArray'), parameters('thirdArray'))]"; expected = @() }
     @{ expression = "[intersection(parameters('firstObject'), parameters('firstArray'))]"; isError = $true }
+    # Test with 3 arrays - should find common elements across all three
+    @{ expression = "[intersection(parameters('firstArray'), parameters('secondArray'), parameters('fifthArray'))]"; expected = @('cd') }
+    # Test with 3 objects - should find properties with matching key-value pairs across all three
+    @{ expression = "[intersection(parameters('firstObject'), parameters('secondObject'), parameters('sixthObject'))]"; expected = [pscustomobject]@{ two = 'b' } }
+    # Test with nested objects - should match deep equality
+    @{ expression = "[intersection(parameters('nestedObject1'), parameters('nestedObject2'))]"; expected = [pscustomobject]@{ 
+      shared = [pscustomobject]@{ value = 42; flag = $true }
+      level = 1
+    } }
+    # Test with nested objects - no common nested properties
+    @{ expression = "[intersection(parameters('nestedObject1'), parameters('nestedObject3'))]"; expected = [pscustomobject]@{ level = 1 } }
+    # Test with 3 nested objects
+    @{ expression = "[intersection(parameters('nestedObject1'), parameters('nestedObject2'), parameters('nestedObject4'))]"; expected = [pscustomobject]@{ level = 1 } }
   ) {
     param($expression, $expected, $isError)
 
@@ -144,6 +157,42 @@ Describe 'tests for function expressions' {
                 defaultValue:
                   three: d
                   four: e
+              sixthObject:
+                type: object
+                defaultValue:
+                  two: b
+                  five: f
+              nestedObject1:
+                type: object
+                defaultValue:
+                  shared:
+                    value: 42
+                    flag: true
+                  level: 1
+                  unique1: test
+              nestedObject2:
+                type: object
+                defaultValue:
+                  shared:
+                    value: 42
+                    flag: true
+                  level: 1
+                  unique2: test
+              nestedObject3:
+                type: object
+                defaultValue:
+                  shared:
+                    value: 24
+                    flag: true
+                  level: 1
+                  unique3: test
+              nestedObject4:
+                type: object
+                defaultValue:
+                  level: 1
+                  different:
+                    value: 100
+                    flag: false
               firstArray:
                 type: array
                 defaultValue:
@@ -165,6 +214,11 @@ Describe 'tests for function expressions' {
                 - gh
                 - ef
                 - ij
+              fifthArray:
+                type: array
+                defaultValue:
+                - cd
+                - kl
             resources:
             - name: Echo
               type: Microsoft.DSC.Debug/Echo
diff --git a/dsc_lib/src/functions/intersection.rs b/dsc_lib/src/functions/intersection.rs
index f8ceceaf1..6c0dd4a9a 100644
--- a/dsc_lib/src/functions/intersection.rs
+++ b/dsc_lib/src/functions/intersection.rs
@@ -31,8 +31,7 @@ impl Function for Intersection {
     fn invoke(&self, args: &[Value], _context: &Context) -> Result<Value, DscError> {
         debug!("{}", t!("functions.intersection.invoked"));
         
-        if args[0].is_array() {
-            let first_array = args[0].as_array().unwrap();
+        if let Some(first_array) = args[0].as_array() {
             let mut result = Vec::new();
             
             for item in first_array {
@@ -57,8 +56,7 @@ impl Function for Intersection {
             return Ok(Value::Array(result));
         }
 
-        if args[0].is_object() {
-            let first_object = args[0].as_object().unwrap();
+        if let Some(first_object) = args[0].as_object() {
             let mut result = Map::new();
             
             for (key, value) in first_object {

From acaf936b911b07b12974e47bbc4d735b41d145c1 Mon Sep 17 00:00:00 2001
From: "G.Reijn" <gijsreijn@hotmail.com>
Date: Sat, 27 Sep 2025 01:50:29 +0200
Subject: [PATCH 8/9] Remove comments

---
 dsc/tests/dsc_functions.tests.ps1 | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/dsc/tests/dsc_functions.tests.ps1 b/dsc/tests/dsc_functions.tests.ps1
index 7b3dce608..75d193002 100644
--- a/dsc/tests/dsc_functions.tests.ps1
+++ b/dsc/tests/dsc_functions.tests.ps1
@@ -118,18 +118,13 @@ Describe 'tests for function expressions' {
     @{ expression = "[intersection(parameters('thirdObject'), parameters('fourthObject'))]"; expected = [pscustomobject]@{ three = 'd' } }
     @{ expression = "[intersection(parameters('firstArray'), parameters('thirdArray'))]"; expected = @() }
     @{ expression = "[intersection(parameters('firstObject'), parameters('firstArray'))]"; isError = $true }
-    # Test with 3 arrays - should find common elements across all three
     @{ expression = "[intersection(parameters('firstArray'), parameters('secondArray'), parameters('fifthArray'))]"; expected = @('cd') }
-    # Test with 3 objects - should find properties with matching key-value pairs across all three
     @{ expression = "[intersection(parameters('firstObject'), parameters('secondObject'), parameters('sixthObject'))]"; expected = [pscustomobject]@{ two = 'b' } }
-    # Test with nested objects - should match deep equality
     @{ expression = "[intersection(parameters('nestedObject1'), parameters('nestedObject2'))]"; expected = [pscustomobject]@{ 
       shared = [pscustomobject]@{ value = 42; flag = $true }
       level = 1
     } }
-    # Test with nested objects - no common nested properties
     @{ expression = "[intersection(parameters('nestedObject1'), parameters('nestedObject3'))]"; expected = [pscustomobject]@{ level = 1 } }
-    # Test with 3 nested objects
     @{ expression = "[intersection(parameters('nestedObject1'), parameters('nestedObject2'), parameters('nestedObject4'))]"; expected = [pscustomobject]@{ level = 1 } }
   ) {
     param($expression, $expected, $isError)

From 5bcd2040fa1697f3f0e2733025078bbc06f7b2b9 Mon Sep 17 00:00:00 2001
From: "G.Reijn" <gijsreijn@hotmail.com>
Date: Sat, 27 Sep 2025 02:20:01 +0200
Subject: [PATCH 9/9] Fix vec

---
 dsc_lib/src/functions/intersection.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dsc_lib/src/functions/intersection.rs b/dsc_lib/src/functions/intersection.rs
index 6c0dd4a9a..292529ea3 100644
--- a/dsc_lib/src/functions/intersection.rs
+++ b/dsc_lib/src/functions/intersection.rs
@@ -16,7 +16,7 @@ impl Function for Intersection {
         FunctionMetadata {
             name: "intersection".to_string(),
             description: t!("functions.intersection.description").to_string(),
-            category: FunctionCategory::Array,
+            category: vec![FunctionCategory::Array, FunctionCategory::Object],
             min_args: 2,
             max_args: usize::MAX,
             accepted_arg_ordered_types: vec![