Merge pull request #3163 from dawedawe/fix_3145

Fix idempotency issue with comment after type decl without equals, 3145

Author: dawedawe

CHANGELOG.md

@@ -8,6 +8,7 @@
 
 ### Fixed
 
+* New lines are added after comment in measure type. [#3145](https://github.com/fsprojects/fantomas/issues/3145)
 * Idempotency problem with comments in applications on lambda expressions. [#3128](https://github.com/fsprojects/fantomas/issues/3128)
 
 ## 7.0.1 - 2025-02-21

src/Fantomas.Core.Tests/TypeDeclarationTests.fs

@@ -3681,3 +3681,21 @@ type X = X
 
         static member x = 1
 """
+
+[<Test>]
+let ``type without body but with comment produces superfluous newline, 3145`` () =
+    formatSourceString
+        """
+type X // oh dear
+
+23
+    """
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+type X // oh dear
+
+23
+"""

src/Fantomas.Core/CodePrinter.fs

@@ -3472,9 +3472,9 @@ let genTypeDefn (td: TypeDefn) =
                 if isMulti && ctx.Config.AlternativeLongMemberDefinitions then
                     (optSingle genSingleTextNode typeName.EqualsToken) ctx
                 else
-                    (sepSpaceOrIndentAndNlnIfExpressionExceedsPageWidth (
-                        optSingle genSingleTextNode typeName.EqualsToken
-                    ))
+                    optSingle
+                        (fun eq -> sepSpaceOrIndentAndNlnIfExpressionExceedsPageWidth (genSingleTextNode eq))
+                        typeName.EqualsToken
                         ctx)
         |> genNode typeName