From 1b299555b93e7e908e480beb8ff8dc853242a7dd Mon Sep 17 00:00:00 2001
From: nojaf <florian.verdonck@outlook.com>
Date: Fri, 26 Mar 2021 20:27:34 +0100
Subject: [PATCH] genTrivia for SynExpr.TypeApp. Fixes #1543.

---
 src/Fantomas.Tests/CompilerDirectivesTests.fs | 31 +++++++++++++++++++
 src/Fantomas/CodePrinter.fs                   |  1 +
 2 files changed, 32 insertions(+)

diff --git a/src/Fantomas.Tests/CompilerDirectivesTests.fs b/src/Fantomas.Tests/CompilerDirectivesTests.fs
index a4335b049b..25066927e8 100644
--- a/src/Fantomas.Tests/CompilerDirectivesTests.fs
+++ b/src/Fantomas.Tests/CompilerDirectivesTests.fs
@@ -2414,3 +2414,34 @@ let tcrefObjTy, enclosingDeclaredTypars, renaming, objTy =
     FreshenTyconRef m rigid tcref declaredTyconTypars
 #endif
 """
+
+[<Test>]
+let ``defines as trivia for SynExpr.TypeApp, 1543`` () =
+    formatSourceString
+        false
+        """
+let inputFileFlagsFsiBase (_tcConfigB: TcConfigBuilder) =
+#if NETSTANDARD
+    [ CompilerOption("usesdkrefs", tagNone, OptionSwitch (SetUseSdkSwitch _tcConfigB), None, Some (FSComp.SR.useSdkRefs())) ]
+#else
+    List.empty<CompilerOption>
+#endif
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+let inputFileFlagsFsiBase (_tcConfigB: TcConfigBuilder) =
+#if NETSTANDARD
+    [ CompilerOption(
+          "usesdkrefs",
+          tagNone,
+          OptionSwitch(SetUseSdkSwitch _tcConfigB),
+          None,
+          Some(FSComp.SR.useSdkRefs ())
+      ) ]
+#else
+    List.empty<CompilerOption>
+#endif
+"""
diff --git a/src/Fantomas/CodePrinter.fs b/src/Fantomas/CodePrinter.fs
index 79f78cf25a..25ed60a679 100644
--- a/src/Fantomas/CodePrinter.fs
+++ b/src/Fantomas/CodePrinter.fs
@@ -2706,6 +2706,7 @@ and genExpr astContext synExpr ctx =
             | SynExpr.ObjExpr _ -> genTriviaFor SynExpr_ObjExpr synExpr.Range
             | SynExpr.JoinIn _ -> genTriviaFor SynExpr_JoinIn synExpr.Range
             | SynExpr.Do _ -> genTriviaFor SynExpr_Do synExpr.Range
+            | SynExpr.TypeApp _ -> genTriviaFor SynExpr_TypeApp synExpr.Range
             | _ -> id)
 
     expr ctx