Bug: Line break before bracket on long method call followed by member access causes semantic change

[reinux]

Issue created from fantomas-online

Code

Microsoft.FSharp.Reflection.FSharpType.GetUnionCases(typeof<option<option<unit>>>.GetGenericTypeDefinition().MakeGenericType(t)).Assembly

Result

Microsoft.FSharp.Reflection.FSharpType.GetUnionCases
    (typeof<option<option<unit>>>.GetGenericTypeDefinition().MakeGenericType(t)).Assembly

Problem description

Because of the line break inserted before the bracket, FSC interprets GetUnionCases in the output to be a function rather than a method.

Typed AST of source:

[Entity
   (Tmp,
    [InitAction
       Call
  (None, val raise, [], [type Microsoft.FSharp.Core.obj],
   [Const (1, type Microsoft.FSharp.Core.int32)])])]

Typed AST of Fantomas output:

[Entity
   (Tmp,
    [InitAction
       Call
  (None, val raise, [],
   [type Microsoft.FSharp.Reflection.UnionCaseInfo Microsoft.FSharp.Core.[]],
   [Const (1, type Microsoft.FSharp.Core.int32)])])]

Extra information

• The formatted result breaks by code.
• The formatted result gives compiler warnings.
• I or my company would be willing to help fix this.

Options

Fantomas Master at 08/10/2020 06:52:52 - 6d8f084

Name	Value
IndentSize	4
MaxLineLength	120
SemicolonAtEndOfLine	false
SpaceBeforeParameter	true
SpaceBeforeLowercaseInvocation	true
SpaceBeforeUppercaseInvocation	false
SpaceBeforeClassConstructor	false
SpaceBeforeMember	false
SpaceBeforeColon	false
SpaceAfterComma	true
SpaceBeforeSemicolon	false
SpaceAfterSemicolon	true
IndentOnTryWith	false
SpaceAroundDelimiter	true
MaxIfThenElseShortWidth	40
MaxInfixOperatorExpression	50
MaxRecordWidth	40
MaxArrayOrListWidth	40
MaxValueBindingWidth	40
MaxFunctionBindingWidth	40
MultilineBlockBracketsOnSameColumn	false
NewlineBetweenTypeDefinitionAndMembers	false
KeepIfThenInSameLine	false
MaxElmishWidth	40
SingleArgumentWebMode	false
AlignFunctionSignatureToIndentation	false
AlternativeLongMemberDefinitions	false
StrictMode	false

[nojaf]

Hey @reinux, would it be possible to provide the full sample code for this?
I'm working on #501 and my changes would change the outcome of this issue to

Microsoft.FSharp.Reflection.FSharpType.GetUnionCases(typeof<option<option<unit>>>
        .GetGenericTypeDefinition()
        .MakeGenericType(t))
    .Assembly

I'd like to be sure that this code still works when outputted like this.
What is t in this case?

[reinux]

Hey, I've been trying to find it in my code, but I can't :(

I may have removed it. I can't quite remember what I was trying to do with that code either.

Sorry about that.

I'm trying it out now, and it looks like that .Assembly might be misplaced. There's a good chance I just typed up some semi-random stuff in fantomas-online that exposed the problem without sharing my own actual code.