From df6f31d7c6c57a487b8962e488b43448eb5b69dd Mon Sep 17 00:00:00 2001
From: nojaf <florian.verdonck@outlook.com>
Date: Fri, 13 Sep 2019 08:34:41 +0200
Subject: [PATCH] Keep parentheses around dynamic operator ident, fixes #476

---
 src/Fantomas.Tests/DynamicOperatorTests.fs | 17 +++++++++++++++++
 src/Fantomas/CodePrinter.fs                |  9 +++++++--
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/src/Fantomas.Tests/DynamicOperatorTests.fs b/src/Fantomas.Tests/DynamicOperatorTests.fs
index 0776d0627d..d62f9b9518 100644
--- a/src/Fantomas.Tests/DynamicOperatorTests.fs
+++ b/src/Fantomas.Tests/DynamicOperatorTests.fs
@@ -15,3 +15,20 @@ let ``Remove () when dynamic operator is string``() =
     formatSourceString false "let memoEquals x = x?k" config
     |> should equal """let memoEquals x = x?k
 """
+
+[<Test>]
+let ``keep () when dynamic operator inside boolean expr, #476`` () =
+    formatSourceString false """let fieldColor (fieldNameX: string) =
+    if f.errors?(fieldNameY) && f.touched?(fieldNameZ) then
+        IsDanger
+    else
+        NoColor
+    |> Input.Color
+"""  config
+    |> prepend newline
+    |> should equal """
+let fieldColor (fieldNameX: string) =
+    if f.errors?(fieldNameY) && f.touched?(fieldNameZ) then IsDanger
+    else NoColor
+    |> Input.Color
+"""
\ No newline at end of file
diff --git a/src/Fantomas/CodePrinter.fs b/src/Fantomas/CodePrinter.fs
index 9cc0392d70..31dff7af48 100644
--- a/src/Fantomas/CodePrinter.fs
+++ b/src/Fantomas/CodePrinter.fs
@@ -1144,8 +1144,13 @@ and genInfixApps astContext hasNewLine synExprs =
     | (s, opE, e)::es when(hasNewLine) ->
         (sepNln +> tok opE.Range s +> sepSpace +> genExpr astContext e)
         +> genInfixApps astContext (hasNewLine || checkNewLine e es) es
-    | (s, opE, e)::es when(NoSpaceInfixOps.Contains s) -> 
-        (tok opE.Range s +> autoNln (genExpr astContext e))
+    | (s, opE, e)::es when(NoSpaceInfixOps.Contains s) ->
+        let wrapExpr f =
+            match synExprs with
+            | ("?", SynExpr.Ident(Ident("op_Dynamic")), SynExpr.Ident(_))::_ ->
+                sepOpenT +> f +> sepCloseT
+            | _ -> f
+        (tok opE.Range s +> autoNln (wrapExpr (genExpr astContext e)))
         +> genInfixApps astContext (hasNewLine || checkNewLine e es) es
     | (s, opE, e)::es ->
         (sepSpace +> autoNln (tok opE.Range s +> sepSpace +> genCommentsAfterInfix (Some opE.Range) +> genExpr astContext e))