Shebang directives get removed from scripts

[mataha]

Issue created from fantomas-online

Code

#!/usr/bin/env -S dotnet fsi --warn:5 --warnon:1182 --warnaserror+

open System
// ...

Result

open System
// ...

Problem description

See fsharp/fslang-design#683.

Extra information

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

Options

Fantomas master branch at 2022-07-15T14:30:45Z - 87cd212

    { config with
                MaxIfThenElseShortWidth = 40
                MaxInfixOperatorExpression = 50
                MaxArrayOrListWidth = 40
                MaxDotGetExpressionWidth = 50
                NewlineBetweenTypeDefinitionAndMembers = false }

_{Did you know that you can ignore files when formatting from fantomas-tool or the FAKE targets by using a .fantomasignore file?}

[nojaf]

Hello, thank you for raising this. The shebang is currently captured as a code comment but is not restored correctly. This is due to an assumption that all non-block code comments start with //.

fantomas/src/Fantomas.Core/Trivia.fs

Lines 80 to 93 in 452064c

	| CommentTrivia.LineComment r ->
	let content = source.GetContentAt r
	let line = source.GetLineString(r.StartLine - 1)
	let item =
	Comment(
	if line.TrimStart(' ', ';').StartsWith("//") then
	CommentOnSingleLine content
	else
	LineCommentAfterSourceCode content
	)
	{ Item = item; Range = r })

would need to be something like

        | CommentTrivia.LineComment r ->
            let content = source.GetContentAt r

            let line = source.GetLineString(r.StartLine - 1)

            let item =
                let trimmedLine = line.TrimStart(' ', ';')
                Comment(
                    if trimmedLine.StartsWith("//") || trimmedLine.StartsWith("#!") then
                        CommentOnSingleLine content
                    else
                        LineCommentAfterSourceCode content
                )

            { Item = item; Range = r })

Are you interested in submitting a PR for this one?

[mataha]

Sure; in fact I was writing a comment asking where to start, as I'd imagine starting with modifying hash regex wouldn't cut it.

[nojaf]

We probably even no longer need that hash regex.
Let me know if you need any help. Our Contribution Guidelines are a good place to start.