[Suggestion] Vite plugin could use git's ignore rules instead of parsing `.gitignore` directly

[webbertakken]

The @tailwindcss/vite plugin (v4.1.18 or v4.2.1) reads the repo-level .gitignore when deciding which files to skip during source detection. There have been edge cases of which all of them are relevant today. It does not respect:

• Global gitignore (core.excludesFile / ~/.gitignore_global)
• .git/info/exclude
• Per-directory .gitignore files in parent directories
• Repository root .gitignore for monorepos if the app is in a workspace.

And has caused the following issues/discussions:

• Tailwind v4 @source directive ignores subdirectories with .gitignore #15452
• [v4]Can't resolve 'tailwindcss' in... #16661
• `[plugin:@tailwindcss/vite:generate:serve] Invalid code point 15530851` error after tailwind v3 -> v4 upgrade #18311

This causes Invalid code point crashes when ignored files (e.g. auto-generated
markdown with hex strings) are scanned and contain sequences that look like CSS hex
escapes.

Reproduce like this

1. Add a file to your global gitignore (e.g. ALL_PROMPTS.md in ~/.gitignore_global)
2. Place that file in the project with content containing a \ followed by 6+ hex
   characters (e.g. \aaec5c)
3. Run vite dev — crashes with Invalid code point 11201628

Expected behaviour

File is ignored (git considers it ignored via git check-ignore -v)

Actual

File is scanned.

Tailwind scans the file, interprets \aaec5c as a CSS hex escape, calls String.fromCodePoint(0xaaec5c) which is 11201628 — beyond Unicode max (0x10FFFF), crashing with:

[plugin:@tailwindcss/vite:generate:serve] Invalid code point 11201628, hex sequence overflows `String.fromCodePoint()`

Suggestion

Use git ls-files --others --ignored --exclude-standard or the ignore npm package with all standard gitignore sources, rather than only reading the repo .gitignore.

Workaround available

Option 1

Add @source not "../../SPECIFIC_FILE.md" in globals.css

Option 2

Add the file to the repo-level .gitignore. (does not work for monorepos, then add it to the workspace .gitignore instead.)

Option 3

Or you could just delete the file if you don't need it.

[wongjn]

I tried a new Vite v7 project with \aaec5c content in an ALL_PROMPTS.md file but could not reproduce the error. Otherwise;

Global

It seems like global gitignores are explicitly disabled:

tailwindcss/crates/oxide/src/scanner/mod.rs

Lines 720 to 721 in a4be983

	// Don't respect global gitignore files
	builder.git_global(false);

.git/info/exclude

There does seem to be support for .git/info/exclude:

tailwindcss/crates/ignore/src/dir.rs

Lines 951 to 961 in a4be983

	fn git_exclude() {
	let td = tmpdir();
	mkdirp(td.path().join(".git/info"));
	wfile(td.path().join(".git/info/exclude"), "foo\n!bar");
	let (ig, err) = IgnoreBuilder::new().build().add_child(td.path());
	assert!(err.is_none());
	assert!(ig.matched("foo", false).is_ignore());
	assert!(ig.matched("bar", false).is_whitelist());
	assert!(ig.matched("baz", false).is_none());
	}

This is enabled by default:

tailwindcss/crates/ignore/src/dir.rs

Lines 774 to 783 in a4be983

	/// Enables reading `.git/info/exclude` files.
	///
	/// `.git/info/exclude` files have match semantics as described in the
	/// `gitignore` man page.
	///
	/// This is enabled by default.
	pub(crate) fn git_exclude(&mut self, yes: bool) -> &mut IgnoreBuilder {
	self.opts.git_exclude = yes;
	self
	}

tailwindcss/crates/ignore/src/walk.rs

Lines 849 to 858 in a4be983

	/// Enables reading `.git/info/exclude` files.
	///
	/// `.git/info/exclude` files have match semantics as described in the
	/// `gitignore` man page.
	///
	/// This is enabled by default.
	pub fn git_exclude(&mut self, yes: bool) -> &mut WalkBuilder {
	self.ig_builder.git_exclude(yes);
	self
	}

And I could not find any explicit disabling of this in oxide.

Either way, consider providing a git repo that reproduces the issues and we can take a look.