Error when parsing keys with hyphen in some JSON files

[Azarattum]

What version of Bun is running?

1.0.13+f5bf67bd1

What platform is your computer?

Linux 5.15.0-101.103.2.1.el8uek.x86_64 x86_64 x86_64

What steps can reproduce the bug?

When importing/requiring some JSON files that contain hyphens in the keys, Bun can throw a syntax error. Currently can reproduce with files named tsconfig.json. Maybe parsing of tsconfig is somehow different?

echo '{ "key-with-hyphen": true }' > tsconfig.json
bun -e 'require("./tsconfig.json")'

Results in:

SyntaxError: Unexpected token '-'. Expected '}' to end an export list.
      at /home/tsconfig.json:1:2

With files named other than tsconfig.json everything works as expected:

echo '{ "key-with-hyphen": true }' > demo.json
bun -e 'require("./demo.json")'

What is the expected behavior?

All JSON files should be treated and parsed the same.

What do you see instead?

tsconfig.json files throw when threre are hyphens in keys.

Additional information

The issue was discovered with tsconfig.json containing a key for ts-node configuration (which includes a hyphen).

[Jarred-Sumner]

Interesting

[DontBreakAlex]

So it turns out that JSON config files are handled differently

bun/src/bun.js/module_loader.zig

Lines 1574 to 1585 in 22818e6

	if (loader == .json and !path.isJSONCFile()) {
	return ResolvedSource{
	.allocator = null,
	.source_code = bun.String.create(parse_result.source.contents),
	.specifier = input_specifier,
	.source_url = if (input_specifier.eqlUTF8(path.text)) input_specifier.dupeRef() else String.init(path.text),
	.hash = 0,
	.tag = ResolvedSource.Tag.json_for_object_loader,
	};
	}

bun/src/fs.zig

Lines 1608 to 1615 in 22818e6

	pub fn isJSONCFile(this: *const Path) bool {
	const str = this.name.filename;
	if (!(strings.hasPrefixComptime(str, "tsconfig.") or strings.hasPrefixComptime(str, "jsconfig."))) {
	return false;
	}
	return strings.hasSuffixComptime(str, ".json");
	}

They go through are a special parser

bun/src/json_parser.zig

Line 885 in 22818e6

pub fn ParseTSConfig(source: *const logger.Source, log: *logger.Log, allocator: std.mem.Allocator) !Expr {

and are rewritten as modules, thus producing a syntax error in this case:

var key_with_hyphen = !0

export {
    key_with_hyphen as key-with-hyphen
};

export default { "key-with-hyphen": key_with_hyphen };

@Jarred-Sumner why are these files rewritten like this ? Is it for JSON5 compatibility ?

[DontBreakAlex]

According to MDN quoting the alias should work, but I get the same error rewriting it like this:

var key_with_hyphen = !0

export {
    key_with_hyphen as "key-with-hyphen"
};

export default { "key-with-hyphen": key_with_hyphen };

Edit: I'm not sure why this is not working, according WebKit's Bugzilla this has been supported for a while...