From 7b52594dea8a82ad260fd060bb1561e325139d4d Mon Sep 17 00:00:00 2001
From: Eugene Auduchinok <eugene.auduchinok@jetbrains.com>
Date: Sat, 23 Mar 2019 21:40:50 +0300
Subject: [PATCH] Support anon record expressions

---
 src/Fantomas.Tests/RecordTests.fs | 30 +++++++++++++++++++++++++++++-
 src/Fantomas/CodePrinter.fs       | 14 ++++++++++++++
 src/Fantomas/Context.fs           | 12 ++++++++++--
 src/Fantomas/SourceParser.fs      |  7 +++++++
 4 files changed, 60 insertions(+), 3 deletions(-)

diff --git a/src/Fantomas.Tests/RecordTests.fs b/src/Fantomas.Tests/RecordTests.fs
index 4c60f9987c..f433f9657c 100644
--- a/src/Fantomas.Tests/RecordTests.fs
+++ b/src/Fantomas.Tests/RecordTests.fs
@@ -259,4 +259,32 @@ type MyExc =
         { inherit Exception(msg)
           X = 1
           Y = 2 }
-"""
\ No newline at end of file
+"""
+
+[<Test>]
+let ``anon record expression``() =
+    formatSourceString false """
+let r =
+    {| Foo = 123
+       Bar = "" |}
+"""  config
+  |> prepend newline
+  |> should equal """
+let r =
+    {| Foo = 123
+       Bar = "" |}
+"""
+
+[<Test>]
+let `` anon record struct expression``() =
+    formatSourceString false """
+let r =
+    struct {| Foo = 123
+              Bar = "" |}
+"""  config
+  |> prepend newline
+  |> should equal """
+let r =
+    struct {| Foo = 123
+              Bar = "" |}
+"""
diff --git a/src/Fantomas/CodePrinter.fs b/src/Fantomas/CodePrinter.fs
index 33b9c72eb9..587ec20972 100644
--- a/src/Fantomas/CodePrinter.fs
+++ b/src/Fantomas/CodePrinter.fs
@@ -473,6 +473,9 @@ and genVal astContext (Val(ats, px, ao, s, t, vi, _)) =
 and genRecordFieldName astContext (RecordFieldName(s, eo)) =
     opt sepNone eo (fun e -> !- s +> sepEq +> preserveBreakNlnOrAddSpace astContext e)
 
+and genAnonRecordFieldName astContext (AnonRecordFieldName(s, e)) =
+    !- s +> sepEq +> preserveBreakNlnOrAddSpace astContext e
+
 and genTuple astContext es =
     atCurrentColumn (coli sepComma es (fun i -> 
             if i = 0 then genExpr astContext else noIndentBreakNln astContext
@@ -539,6 +542,17 @@ and genExpr astContext synExpr =
             (fun (typ, expr) -> !- "inherit " +> genType astContext false typ +> genExpr astContext expr) +> recordExpr)
         +> sepCloseS
 
+    | AnonRecord(isStruct, fields, copyInfo) -> 
+        let recordExpr = 
+            let fieldsExpr = col sepSemiNln fields (genAnonRecordFieldName astContext)
+            copyInfo |> Option.map (fun e ->
+                genExpr astContext e +> ifElseCtx (futureNlnCheck fieldsExpr) (!- " with" +> indent +> sepNln +> fieldsExpr +> unindent) (!- " with " +> fieldsExpr))
+            |> Option.defaultValue fieldsExpr
+        ifElse isStruct !- "struct " sepNone 
+        +> sepOpenAnonRecd
+        +> atCurrentColumnIndent recordExpr
+        +> sepCloseAnonRecd
+
     | ObjExpr(t, eio, bd, ims, range) ->
         // Check the role of the second part of eio
         let param = opt sepNone (Option.map fst eio) (genExpr astContext)
diff --git a/src/Fantomas/Context.fs b/src/Fantomas/Context.fs
index 10d61647bb..fbfde4330e 100644
--- a/src/Fantomas/Context.fs
+++ b/src/Fantomas/Context.fs
@@ -295,14 +295,22 @@ let internal sepOpenAFixed = !- "[|"
 /// closing token of list
 let internal sepCloseAFixed = !- "|]"
 
-/// opening token of sequence
+/// opening token of sequence or record
 let internal sepOpenS (ctx : Context) = 
     if ctx.Config.SpaceAroundDelimiter then str "{ " ctx else str "{" ctx 
 
-/// closing token of sequence
+/// closing token of sequence or record
 let internal sepCloseS (ctx : Context) = 
     if ctx.Config.SpaceAroundDelimiter then str " }" ctx else str "}" ctx
 
+/// opening token of anon record
+let internal sepOpenAnonRecd (ctx : Context) =
+    if ctx.Config.SpaceAroundDelimiter then str "{| " ctx else str "{|" ctx 
+
+/// closing token of anon record
+let internal sepCloseAnonRecd (ctx : Context) =
+    if ctx.Config.SpaceAroundDelimiter then str " |}" ctx else str "|}" ctx
+
 /// opening token of sequence
 let internal sepOpenSFixed = !- "{"
 
diff --git a/src/Fantomas/SourceParser.fs b/src/Fantomas/SourceParser.fs
index 8b1c12c758..5780bf604f 100644
--- a/src/Fantomas/SourceParser.fs
+++ b/src/Fantomas/SourceParser.fs
@@ -808,6 +808,11 @@ let (|Record|_|) = function
         Some(inheritOpt, xs, Option.map fst eo)
     | _ -> None
 
+let (|AnonRecord|_|) = function
+    | SynExpr.AnonRecd(isStruct, copyInfo, fields, _) ->
+        Some(isStruct, fields, Option.map fst copyInfo)
+    | _ -> None
+
 let (|ObjExpr|_|) = function
     | SynExpr.ObjExpr(t, eio, bd, ims, _, range) ->
         Some (t, eio, bd, ims, range)
@@ -1207,6 +1212,8 @@ let (|Val|) (ValSpfn(ats, IdentOrKeyword(OpNameFull s), tds, t, vi, _, _, px, ao
 
 let (|RecordFieldName|) ((LongIdentWithDots s, _) : RecordFieldName, eo : SynExpr option, _) = (s, eo)
 
+let (|AnonRecordFieldName|) ((Ident s): Ident, e: SynExpr) = (s, e)
+
 let (|PatRecordFieldName|) ((LongIdent s1, Ident s2), p) = (s1, s2, p)
 
 let (|ValInfo|) (SynValInfo(aiss, ai)) = (aiss, ai)