Add indent when line comment precedes type info, fsprojects#565 (fspr…

…ojects#617)
nojaf · Jan 3, 2020 · 28bf163 · 28bf163
1 parent ad6a81f
commit 28bf163
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Showing 3 changed files with 36 additions and 2 deletions.
diff --git a/src/Fantomas.Tests/LetBindingTests.fs b/src/Fantomas.Tests/LetBindingTests.fs
@@ -319,6 +319,28 @@ let x =
     if true then 1 else 0
 """
 
+[<Test>]
+let ``line comment before return type info should indent before colon, 565`` () =
+    formatSourceString false """module Bar =
+  let f a
+    // foo
+    : int
+    =
+    0
+"""  ({ config with
+            SpaceAfterComma = false
+            SpaceAfterSemicolon = false
+            SpaceAroundDelimiter = false
+            SpaceBeforeArgument = false })
+    |> prepend newline
+    |> should equal """
+module Bar =
+    let f a
+        // foo
+        : int =
+            0
+"""
+
 [<Test>]
 let ``has symbol in signature requires paren, 564`` () =
     formatSourceString false """module Bar =

diff --git a/src/Fantomas/CodePrinter.fs b/src/Fantomas/CodePrinter.fs
@@ -489,7 +489,13 @@ and genExprSepEqPrependType astContext prefix (pat:SynPat) e ctx =
                 addSpaceAfterGenericConstructBeforeColon
             | _ -> sepNone
 
-        (prefix +> addExtraSpaceBeforeGenericType +> sepColon +> genType astContext false t +> sepEq
+        let genCommentBeforeColon ctx =
+            let hasLineComment = TriviaHelpers.``has line comment before`` t.Range ctx.Trivia
+            (ifElse hasLineComment indent sepNone +> enterNode t.Range) ctx
+
+        (prefix +> addExtraSpaceBeforeGenericType
+        +> genCommentBeforeColon
+        +> sepColon +> genType astContext false t +> sepEq
         +> breakNlnOrAddSpace astContext (hasTriviaContentAfterEqual || multilineCheck || checkPreserveBreakForExpr e ctx) e) ctx
     | e ->
 

diff --git a/src/Fantomas/TriviaHelpers.fs b/src/Fantomas/TriviaHelpers.fs
@@ -45,4 +45,10 @@ module TriviaHelpers =
             | Comment(LineCommentAfterSourceCode(_)) -> true
             | _ -> false
         )
-        |> (List.isEmpty >> not)
+        |> (List.isEmpty >> not)
+
+    let internal ``has line comment before`` range triviaNodes =
+        triviaNodes
+        |> List.tryFind (fun tv -> tv.Range = range)
+        |> Option.map (fun tv -> tv.ContentBefore |> List.exists (function | Comment(LineCommentOnSingleLine(_)) -> true | _ -> false))
+        |> Option.defaultValue false