Check if expression is isArrayOrListWithHashDirectiveBeforeClosingBra…

…cket in indentSepNlnUnindentUnlessStroustrup

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## [Unreleased]
+
+### Fixed
+* HashDirective before closing `]`. [#3070](https://github.com/fsprojects/fantomas/issues/3070)
+
 ## 6.3.0 - 2024-03-15
 
 ### Miscellaneous

src/Fantomas.Core.Tests/Stroustrup/SynBindingFunctionExpressionTests.fs

@@ -95,6 +95,31 @@ let x y = [
 ]
 """
 
+[<Test>]
+let ``hash directive before closing list bracket, 3070`` () =
+    formatSourceString
+        """
+let private knownProviders = [
+#if !FABLE_COMPILER
+    (SerilogProvider.isAvailable, SerilogProvider.create)
+    (MicrosoftExtensionsLoggingProvider.isAvailable, MicrosoftExtensionsLoggingProvider.create)
+#endif
+                                        ]
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+let private knownProviders =
+    [
+#if !FABLE_COMPILER
+        (SerilogProvider.isAvailable, SerilogProvider.create)
+        (MicrosoftExtensionsLoggingProvider.isAvailable, MicrosoftExtensionsLoggingProvider.create)
+#endif
+    ]
+"""
+
 [<Test>]
 let ``synbinding function with array`` () =
     formatSourceString

src/Fantomas.Core/Context.fs

@@ -936,7 +936,14 @@ let addParenIfAutoNln expr f =
 
 let indentSepNlnUnindentUnlessStroustrup f (e: Expr) (ctx: Context) =
     let shouldUseStroustrup =
-        isStroustrupStyleExpr ctx.Config e && canSafelyUseStroustrup (Expr.Node e) ctx
+        let isArrayOrListWithHashDirectiveBeforeClosingBracket () =
+            match e with
+            | Expr.ArrayOrList node -> Seq.isEmpty node.Closing.ContentBefore
+            | _ -> true
+
+        isStroustrupStyleExpr ctx.Config e
+        && canSafelyUseStroustrup (Expr.Node e) ctx
+        && isArrayOrListWithHashDirectiveBeforeClosingBracket ()
 
     if shouldUseStroustrup then
         f e ctx