Function getParser

src/tools/ast/parser.ts:58–116

(language: string)

}

export async function getParser(language: string): Promise<{ parser: any; language: any } | null> {
  try {
    await initTreeSitter();
  } catch (e: any) {
    logger.warn('Tree-sitter unavailable', { err: e.message });
    return null;
  }

  if (parsersByLang.has(language) && languagesByLang.has(language)) {
    return { parser: parsersByLang.get(language)!, language: languagesByLang.get(language)! };
  }

  // Try to load WASM grammar
  // First look in installed package dir, then in user qodex home
  const grammarFile = `tree-sitter-${language}.wasm`;
  const candidates: string[] = [];

  try {
    const here = path.dirname(url.fileURLToPath(import.meta.url));
    candidates.push(path.join(here, '..', '..', '..', 'grammars', grammarFile));
    candidates.push(path.join(here, '..', '..', '..', '..', 'grammars', grammarFile));
    candidates.push(path.join(process.cwd(), 'grammars', grammarFile));
  } catch {}

  let lang: any = null;
  for (const candidate of candidates) {
    // CRITICAL: only hand Language.load a path that exists. web-tree-sitter's
    // Emscripten loader, given a missing path, kicks off an async file read whose
    // ENOENT rejection floats OUTSIDE the promise we await here — so a try/catch
    // around load() does NOT catch it, and Node 24 crashes the whole process on
    // the unhandled rejection. Pre-checking existence means load() is only ever
    // called on a real file, so a missing grammar degrades to the regex fallback
    // instead of taking down the CLI.
    try {
      await access(candidate);
    } catch {
      continue; // not present — try the next candidate
    }
    try {
      lang = await TSLanguage.load(candidate);
      logger.debug(`Loaded grammar: ${candidate}`);
      break;
    } catch (e: any) {
      logger.warn(`Grammar present but failed to load: ${candidate}`, { err: e?.message });
    }
  }

  if (!lang) {
    logger.warn(`No grammar found for language: ${language}. Looked in: ${candidates.join(', ')}`);
    return null;
  }

  const parser = new TreeSitter();
  parser.setLanguage(lang);
  parsersByLang.set(language, parser);
  languagesByLang.set(language, lang);

  return { parser, language: lang };