[Ammann Labs (agammann)]

Summary

parseRawGrammar selects the JSON parser only when a filename ends in lowercase .json. A valid JSON grammar named example.JSON or example.Json is sent to the PLIST parser and fails with Near offset 1: expected <.

Make the extension check case insensitive. The regression test exercises both filename variants against the existing lowercase behavior.

Reproduction

const source = '{"scopeName":"source.example","patterns":[]}';
parseRawGrammar(source, 'example.JSON');

On main at dec096bc6ab91710e13023a00d029b8195e26c60, this throws from the PLIST parser. With the fix, it parses the JSON grammar.

Validation

• The new focused test fails on unmodified upstream and passes with the fix.
• On Linux with Node 22.23.3, npm ci, npm run compile, and npm test pass: 268 tests passed and one existing test was skipped.
• git diff --check passes.

[Ammann Labs (agammann)]

@microsoft-github-policy-service agree