Add regression test to account for fix of problem in #1407 (#1456)

* Add regression test to account for fix of problem in #1407

* Ran format on DotIndexedGetTests.fs

* Remove local .editorconfig that was interfering with formatting

* Add custom config to regression test

Co-authored-by: Florian Verdonck <florian.verdonck@outlook.com>

src/Fantomas.Tests/DotIndexedGetTests.fs

@@ -70,3 +70,35 @@ myList.[7]
         otherArgument4
     )
 """
+
+[<Test>]
+let ``should not merge tokens inside parentheses, 1407`` () =
+    formatSourceString
+        false
+        """
+let inline (=??) x = (=!) x
+let mySampleMethod() =
+    let result = Ok {| Results = [] |}
+    (Result.okValue result).Results.[0] |> Result.isOk =?? true
+"""
+        { config with
+              SpaceBeforeLowercaseInvocation = false
+              SpaceBeforeColon = true
+              MaxIfThenElseShortWidth = 25
+              MultilineBlockBracketsOnSameColumn = true
+              KeepIfThenInSameLine = true
+              AlignFunctionSignatureToIndentation = true
+              AlternativeLongMemberDefinitions = true
+              MultiLineLambdaClosingNewline = true }
+    |> prepend newline
+    |> should
+        equal
+        """
+let inline (=??) x = (=!) x
+
+let mySampleMethod () =
+    let result = Ok {| Results = [] |}
+
+    (Result.okValue result).Results.[0] |> Result.isOk
+    =?? true
+"""