Emit shebangs when printing

[AlCalzone]

Fixes: #1038

Ideally I'd like to add a test for this, but I have no clue how this works in this repo.

[Copilot]

Pull Request Overview

This PR ensures that a file’s shebang (e.g., #!/usr/bin/env node) is preserved when printing source files.

• Added GetShebang helper to extract the shebang line from text
• Updated Printer.emitShebangIfNeeded to call GetShebang and emit the line
• No tests added for the new functionality

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
internal/scanner/scanner.go	Added GetShebang function to return the shebang line if present
internal/printer/printer.go	Updated emitShebangIfNeeded to call GetShebang and write the shebang to output

Comments suppressed due to low confidence (2)

internal/scanner/scanner.go:2263

• There are no unit tests for GetShebang or the updated emitShebangIfNeeded logic. Adding tests that cover files both with and without a shebang will ensure this feature remains correct.

func GetShebang(text string) string {

internal/printer/printer.go:4341

• Using writeComment may prefix the shebang with comment markers (e.g., //). To emit the shebang exactly as written (including #!), consider using a raw write method such as p.write(shebang).

p.writeComment(shebang)

[jakebailey]

Ideally I'd like to add a test for this, but I have no clue how this works in this repo.

Most likely we already have a test, such that running hereby test and then hereby baseline-accept will update the baselines.

Otherwise, there are printer tests in the printer package you could add to.

[AlCalzone]

Done. I wasn't sure how to interpret the diff, but after accepting the output files look correct to me.

[jakebailey]

Yeah, this looks great to me, thank you!