Invalid code produced when formatting type alias for struct tuple

[maxdeviant]

Issue created from fantomas-ui

When formatting a type alias for a struct tuple the resulting code is not valid F#.

Code

This compiles correctly:

type TupleStruct = (struct (string * string))

Error

This no longer compiles without the wrapping parentheses:

type TupleStruct = struct (string * string)

Note that this seems like it might be a shortcoming in the F# compiler: dotnet/fsharp#7014.

Options

Fantomas 3.1.0

Name	Value
IndentOnTryWith	false
IndentSpaceNum	4
KeepNewlineAfter	false
MaxIfThenElseShortWidth	40
PageWidth	120
ReorderOpenDeclaration	false
SemicolonAtEndOfLine	false
SpaceAfterComma	true
SpaceAfterSemicolon	true
SpaceAroundDelimiter	true
SpaceBeforeArgument	true
SpaceBeforeColon	false
StrictMode	false

[nojaf]

I think it would be possible to always wrap struct tuple in parentheses.