Put multi line named argument on next line. Fixes #1158. (#1159)

build.fsx

@@ -428,7 +428,14 @@ Target.create "Format" (fun _ ->
 
 Target.create "FormatChanged" (fun _ ->
     Fake.Tools.Git.FileStatus.getChangedFilesInWorkingCopy "." "HEAD"
-    |> Seq.choose (fun (_, file) -> if file.StartsWith("src") then Some file else None)
+    |> Seq.choose (fun (_, file) ->
+        let ext = Path.GetExtension(file)
+
+        if file.StartsWith("src")
+           && (ext = ".fs" || ext = ".fsi") then
+            Some file
+        else
+            None)
     |> formatCode
     |> Async.RunSynchronously
     |> printfn "Formatted files: %A")

src/Fantomas.Tests/Fantomas.Tests.fsproj

@@ -74,6 +74,7 @@
     <Compile Include="InterpolatedStringTests.fs" />
     <Compile Include="DotGetTests.fs" />
     <Compile Include="HashDirectiveTests.fs" />
+    <Compile Include="SynExprNewTests.fs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\Fantomas.Extras\Fantomas.Extras.fsproj" />

src/Fantomas.Tests/SynExprNewTests.fs

@@ -0,0 +1,40 @@
+module Fantomas.Tests.SynExprNewTests
+
+open NUnit.Framework
+open FsUnit
+open Fantomas.Tests.TestHelper
+
+[<Test>]
+let ``combination of named and non named arguments, 1158`` () =
+    formatSourceString false """
+    let private sendTooLargeError () =
+        new HttpResponseMessage(HttpStatusCode.RequestEntityTooLarge,
+                                Content =
+                                    new StringContent("File was too way too large",
+                                                      System.Text.Encoding.UTF16,
+                                                      "application/text"))
+"""  config
+    |> prepend newline
+    |> should equal """
+let private sendTooLargeError () =
+    new HttpResponseMessage(HttpStatusCode.RequestEntityTooLarge,
+                            Content =
+                                new StringContent("File was too way too large",
+                                                  System.Text.Encoding.UTF16,
+                                                  "application/text"))
+"""
+
+[<Test>]
+let ``single multi line named argument instance`` () =
+    formatSourceString false """
+let myInstance =
+        new EvilBadRequest(Content = new StringContent("File was too way too large",
+                                                      System.Text.Encoding.UTF16,
+                                                      "application/text"))
+"""  config
+    |> prepend newline
+    |> should equal """
+let myInstance =
+    new EvilBadRequest(Content =
+        new StringContent("File was too way too large", System.Text.Encoding.UTF16, "application/text"))
+"""

src/Fantomas/CodePrinter.fs

@@ -1146,14 +1146,42 @@ and genAnonRecordFieldName astContext (AnonRecordFieldName (s, e)) =
     !-s +> sepEq +> expr
 
 and genTuple astContext es =
-    let f =
-        addParenForTupleWhen (genExpr astContext)
+    let genExpr e =
+        let expr e =
+            match e with
+            | InfixApp (equal, operatorExpr, e1, e2) when (equal = "=") ->
+                genNamedArgumentExpr astContext operatorExpr e1 e2
+            | _ -> genExpr astContext e
+
+        addParenForTupleWhen expr e
 
-    let shortExpression = col sepComma es f
-    let longExpression = col (sepComma +> sepNln) es f
+    let shortExpression = col sepComma es genExpr
+    let longExpression = col (sepComma +> sepNln) es genExpr
 
     atCurrentColumn (expressionFitsOnRestOfLine shortExpression longExpression)
 
+and genNamedArgumentExpr (astContext: ASTContext) operatorExpr e1 e2 =
+    let short =
+        genExpr astContext e1
+        +> sepSpace
+        +> genInfixOperator "=" operatorExpr
+        +> sepSpace
+        +> genExpr astContext e2
+
+    match e2 with
+    | MultilineString _ -> short
+    | _ ->
+        let long =
+            genExpr astContext e1
+            +> sepSpace
+            +> genInfixOperator "=" operatorExpr
+            +> indent
+            +> sepNln
+            +> genExpr astContext e2
+            +> unindent
+
+        expressionFitsOnRestOfLine short long
+
 and genExpr astContext synExpr =
     let appNlnFun e =
         match e with
@@ -1346,31 +1374,6 @@ and genExpr astContext synExpr =
         genExpr astContext e
         +> sepColon
         +> genType astContext false t
-    | TupleWithInfixEqualsApps es ->
-        let expr (e1, opE, e2) =
-            let shortExpr =
-                genExpr astContext e1
-                +> sepSpace
-                +> genInfixOperator "=" opE
-                +> sepSpace
-                +> genExpr astContext e2
-
-            let longExpr =
-                genExpr astContext e1
-                +> sepSpace
-                +> genInfixOperator "=" opE
-                +> indent
-                +> sepNln
-                +> genExpr astContext e2
-                +> unindent
-
-            expressionFitsOnRestOfLine shortExpr longExpr
-
-        let shortExpression = col sepComma es expr
-        let longExpression = col (sepComma +> sepNln) es expr
-
-        atCurrentColumn (expressionFitsOnRestOfLine shortExpression longExpression)
-
     | Tuple es -> genTuple astContext es
     | StructTuple es ->
         !- "struct "
@@ -1710,6 +1713,10 @@ and genExpr astContext synExpr =
                      e
                  +> indentIfNeeded sepNone)
             +> sepCloseTFor rpr
+        | InfixApp (equal, operatorExpr, e1, e2) when (equal = "=") ->
+            sepOpenTFor (Some lpr)
+            +> genNamedArgumentExpr astContext operatorExpr e1 e2
+            +> sepCloseTFor rpr
         | _ ->
             // Parentheses nullify effects of no space inside DotGet
             sepOpenTFor (Some lpr)

src/Fantomas/SourceParser.fs

@@ -835,22 +835,6 @@ let (|SameInfixApps|_|) e =
         | _ -> None
     | _ -> None
 
-let (|TupleWithInfixEqualsApps|_|) e =
-    let isEqualInfix =
-        function
-        | InfixApp ("=", _, _, _) -> true
-        | _ -> false
-
-    match e with
-    | Tuple es when (List.forall isEqualInfix es) ->
-        es
-        |> List.map (fun e ->
-            match e with
-            | InfixApp ("=", opE, e1, e2) -> e1, opE, e2
-            | _ -> failwith "should not be possible")
-        |> Some
-    | _ -> None
-
 let (|TernaryApp|_|) =
     function
     | SynExpr.App (_, _, SynExpr.App (_, _, SynExpr.App (_, true, Var "?<-", e1, _), e2, _), e3, _) -> Some(e1, e2, e3)