Put multiline if expression with comment on next line. Fixes fsprojec…

…ts#1588.
nojaf · Apr 4, 2021 · 24b1dc1 · 24b1dc1
1 parent abb3128
commit 24b1dc1
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Showing 2 changed files with 64 additions and 1 deletion.
diff --git a/src/Fantomas.Tests/IfThenElseTests.fs b/src/Fantomas.Tests/IfThenElseTests.fs
@@ -2122,3 +2122,50 @@ then
 else
     return formattedSourceCode
 """
+
+[<Test>]
+let ``line comment before multiline if expression, 1588`` () =
+    formatSourceString
+        false
+        """
+            if
+              // Don't support implicit [<ReflectedDefinition>] on generated members, except the implicit members
+              // for 'let' bound functions in classes.
+              (not v.IsCompilerGenerated || v.IsIncrClassGeneratedMember) &&
+
+              (// Check the attributes on any enclosing module
+               env.reflect ||
+               // Check the attributes on the value
+               HasFSharpAttribute g g.attrib_ReflectedDefinitionAttribute v.Attribs ||
+               // Also check the enclosing type for members - for historical reasons, in the TAST member values
+               // are stored in the entity that encloses the type, hence we will not have noticed the ReflectedDefinition
+               // on the enclosing type at this point.
+               HasFSharpAttribute g g.attrib_ReflectedDefinitionAttribute v.TopValDeclaringEntity.Attribs) then
+
+                ()
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+if
+    // Don't support implicit [<ReflectedDefinition>] on generated members, except the implicit members
+    // for 'let' bound functions in classes.
+    (not v.IsCompilerGenerated
+     || v.IsIncrClassGeneratedMember)
+    &&
+
+    (env.reflect // Check the attributes on any enclosing module
+     ||
+     // Check the attributes on the value
+     HasFSharpAttribute g g.attrib_ReflectedDefinitionAttribute v.Attribs
+     ||
+     // Also check the enclosing type for members - for historical reasons, in the TAST member values
+     // are stored in the entity that encloses the type, hence we will not have noticed the ReflectedDefinition
+     // on the enclosing type at this point.
+     HasFSharpAttribute g g.attrib_ReflectedDefinitionAttribute v.TopValDeclaringEntity.Attribs)
+then
+
+    ()
+"""
diff --git a/src/Fantomas/CodePrinter.fs b/src/Fantomas/CodePrinter.fs
@@ -2253,6 +2253,14 @@ and genExpr astContext synExpr ctx =
                     let short = genExpr astContext e
 
                     let long =
+                        let hasCommentBeforeExpr () =
+                            TriviaHelpers.``has content before that matches``
+                                (fun tn -> RangeHelpers.rangeEq tn.Range e.Range)
+                                (function
+                                | Comment (LineCommentOnSingleLine _) -> true
+                                | _ -> false)
+                                (Map.tryFindOrEmptyList (synExprToFsAstType e |> fst) ctx.TriviaMainNodes)
+
                         match e with
                         | App (SynExpr.DotGet _, [ (Paren _) ]) -> atCurrentColumn (genExpr astContext e)
                         | Paren (lpr, (AppSingleParenArg _ as ate), rpr, pr) ->
@@ -2316,7 +2324,15 @@ and genExpr astContext synExpr ctx =
                             +> genExpr astContext e
                             +> unindent
                             +> sepNln
-                        | _ -> genExpr astContext e
+                        | _ ->
+                            if hasCommentBeforeExpr () then
+                                indent
+                                +> sepNln
+                                +> genExpr astContext e
+                                +> unindent
+                                +> sepNln
+                            else
+                                genExpr astContext e
 
                     expressionFitsOnRestOfLine short long