Don't use module or namespace as trivia candidate. (#1656)

* Don't use module or namespace as trivia candidate. Fixes #1649.

* Renamed unit test.

* Reimplement colWithNlnWhenItemIsMultiline by including check for trailing trivia.

* Check in recently added items in Queue if expression was multiline.

* Correct renamed in CodePrinter

src/Fantomas.Tests/AttributeTests.fs

@@ -266,9 +266,11 @@ let ``comments before attributes should be added correctly, issue 422`` () =
           Verified : bool }
 """
         config
+    |> prepend newline
     |> should
         equal
-        """module RecordTypes =
+        """
+module RecordTypes =
 
     /// Records can also be represented as structs via the 'Struct' attribute.
     /// This is helpful in situations where the performance of structs outweighs

src/Fantomas.Tests/ColMultilineItemTests.fs

@@ -0,0 +1,370 @@
+module Fantomas.Tests.ColMultilineItemTests
+
+open NUnit.Framework
+open FsUnit
+open Fantomas.Tests.TestHelper
+
+[<Test>]
+let ``two short let binding should not have extra newline`` () =
+    formatSourceString
+        false
+        """
+let a = 2
+let b =  3
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+let a = 2
+let b = 3
+"""
+
+
+[<Test>]
+let ``three short let binding should not have extra newline`` () =
+    formatSourceString
+        false
+        """
+let a = 2
+let b =  3
+let c =   4
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+let a = 2
+let b = 3
+let c = 4
+"""
+
+[<Test>]
+let ``two short expressions inside let binding`` () =
+    formatSourceString
+        false
+        """
+let b () =
+    printfn "meh"
+    80.7
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+let b () =
+    printfn "meh"
+    80.7
+"""
+
+[<Test>]
+let ``short let binding followed by long let binding`` () =
+    formatSourceString
+        false
+        """
+let a =   9
+let b () =
+    printfn "meh"
+    80.7
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+let a = 9
+
+let b () =
+    printfn "meh"
+    80.7
+"""
+
+[<Test>]
+let ``long let binding followed by short let binding`` () =
+    formatSourceString
+        false
+        """
+let b () =
+    printfn "meh"
+    80.7
+let a =   9
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+let b () =
+    printfn "meh"
+    80.7
+
+let a = 9
+"""
+
+[<Test>]
+let ``three long let bindings`` () =
+    formatSourceString
+        false
+        """
+let a =
+    // some comment
+    42
+let b (x:int) (y:int):int =
+    printfn "doing b with %i %i" x y
+    x + y
+let c () =
+    try
+        0
+    with ex -> 1
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+let a =
+    // some comment
+    42
+
+let b (x: int) (y: int) : int =
+    printfn "doing b with %i %i" x y
+    x + y
+
+let c () =
+    try
+        0
+    with ex -> 1
+"""
+
+[<Test>]
+let ``two short let bindings with existing newlines between`` () =
+    formatSourceString
+        false
+        """
+let a = 9
+
+
+let x =  70
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+let a = 9
+
+
+let x = 70
+"""
+
+[<Test>]
+let ``one let binding, newline, long let binding, newline, short let binding`` () =
+    formatSourceString
+        false
+        """
+let a =  0
+
+let b (x: int) (y: int) : int =
+    printfn "doing b with %i %i" x y
+    x +   y
+
+let c =  "a string for a change"
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+let a = 0
+
+let b (x: int) (y: int) : int =
+    printfn "doing b with %i %i" x y
+    x + y
+
+let c = "a string for a change"
+"""
+
+[<Test>]
+let ``short let binding, two comments, short let binding`` () =
+    formatSourceString
+        false
+        """
+let a =  7.0
+// some comment
+// other comment
+let b =   0.0908
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+let a = 7.0
+// some comment
+// other comment
+let b = 0.0908
+"""
+
+[<Test>]
+let ``multiline expression, newline, short expression, short expression`` () =
+    formatSourceString
+        false
+        """
+asyncResult {
+      let job =
+        { JobType = EsriBoundaryImport
+          FileToImport = filePath
+          State = state
+          DryRun = args.DryRun }
+
+      importer.ApiMaster <! StartImportCmd job
+      return Ok job
+    }
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+asyncResult {
+    let job =
+        { JobType = EsriBoundaryImport
+          FileToImport = filePath
+          State = state
+          DryRun = args.DryRun }
+
+    importer.ApiMaster <! StartImportCmd job
+    return Ok job
+}
+"""
+
+[<Test>]
+let ``inner comment should make item multiline`` () =
+    formatSourceString
+        false
+        """
+    let a =
+        // foo
+        getA()
+    return a
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+let a =
+    // foo
+    getA ()
+
+return a
+"""
+
+[<Test>]
+let ``leading comment should not make item multiline`` () =
+    formatSourceString
+        false
+        """
+// You can also implement it via an object expression
+let md' =
+    { new MyDim }
+printfn "DIM from C# but via Object Expression: %d" md'.Z
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+// You can also implement it via an object expression
+let md' = { new MyDim }
+printfn "DIM from C# but via Object Expression: %d" md'.Z
+"""
+
+[<Test>]
+let ``leading newline and comment should not make item multiline`` () =
+    formatSourceString
+        false
+        """
+printfn "DIM from C#: %d" md.Z
+
+// You can also implement it via an object expression
+let md' = { new MyDim }
+printfn "DIM from C# but via Object Expression: %d" md'.Z
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+printfn "DIM from C#: %d" md.Z
+
+// You can also implement it via an object expression
+let md' = { new MyDim }
+printfn "DIM from C# but via Object Expression: %d" md'.Z
+"""
+
+[<Test>]
+let ``multiple leading comments should keep short item short`` () =
+    formatSourceString
+        false
+        """
+// #if INTERACTIVE
+// #else
+#load "../FSharpx.TypeProviders/SetupTesting.fsx"
+SetupTesting.generateSetupScript __SOURCE_DIRECTORY__
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+// #if INTERACTIVE
+// #else
+#load "../FSharpx.TypeProviders/SetupTesting.fsx"
+SetupTesting.generateSetupScript __SOURCE_DIRECTORY__
+"""
+
+[<Test>]
+let ``comment after let binding does not make it multiline`` () =
+    formatSourceString
+        false
+        """
+let a = 7
+let b = 8
+// foo
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+let a = 7
+let b = 8
+// foo
+"""
+
+[<Test>]
+let ``existing blank line between multiline expressions`` () =
+    formatSourceString
+        false
+        """
+open Barry
+printFn ()
+
+open Foo
+open Bar
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+open Barry
+printFn ()
+
+open Foo
+open Bar
+"""