ReactiveX/rxjs · error · Error

Unknown framework: ${framework}

Error message

Unknown framework: ${framework}

What it means

Thrown by parseArguments in the @rxjs/migrate CLI when --framework receives an unrecognized value. Only 'preserve' (leave test framework untouched) and 'mocha-chai-vitest' (rewrite Mocha/Chai assertions to Vitest) are supported; anything else stops parsing.

Source

Thrown at packages/migrate/src/cli.ts:146

        break;
      case '--out-dir':
        options.outputRoot = requiredValue(argv, ++index, argument);
        break;
      case '--source-repo':
        options.repository = requiredValue(argv, ++index, argument);
        break;
      case '--source-sha':
        options.sha = requiredValue(argv, ++index, argument);
        break;
      case '--mode': {
        const mode = requiredValue(argv, ++index, argument);
        if (mode !== 'cold' && mode !== 'platform') throw new Error(`Unknown mode: ${mode}`);
        options.mode = mode;
        break;
      }
      case '--framework': {
        const framework = requiredValue(argv, ++index, argument);
        if (framework !== 'preserve' && framework !== 'mocha-chai-vitest') throw new Error(`Unknown framework: ${framework}`);
        options.framework = framework;
        break;
      }
      case '--write':
        options.write = true;
        break;
      case '--help':
      case '-h':
        options.help = true;
        break;
      default:
        if (argument.startsWith('-')) throw new Error(`Unknown option: ${argument}`);
        options.files.push(argument);
    }
  }
  return options;
}

View on GitHub (pinned to 54796b38a5)

Solutions

1. Use --framework preserve if your framework is not Mocha/Chai
2. Use --framework mocha-chai-vitest only when rewriting Mocha+Chai tests to Vitest
3. Run with --help to confirm accepted values

Example fix

// before
npx @rxjs/migrate --framework jest ...
// after
npx @rxjs/migrate --framework preserve ...

const FRAMEWORKS = new Set(['preserve', 'mocha-chai-vitest']);
if (!FRAMEWORKS.has(framework)) {
  console.error(`--framework must be one of ${[...FRAMEWORKS].join(' | ')}`);
  process.exit(1);
}

const isFramework = (v: string): v is 'preserve' | 'mocha-chai-vitest' => v === 'preserve' || v === 'mocha-chai-vitest';

try { runCli(argv); } catch (e) { console.error((e as Error).message); }

When it happens

Trigger: Passing `--framework jest`, `--framework jasmine`, or a misspelled value like `--framework mochachai` to the CLI.

Common situations: Trying to migrate a Jest or Karma suite (unsupported), assuming framework names from other codemods, or typos in scripts copied from migration docs.

Related errors

• Unknown mode: ${mode}
• Unknown option: ${argument}
• Missing required argument${missing.length === 1 ? '' : 's'}:
• --out-dir is required with --write
• ${option} requires a value

AI-assisted analysis of ReactiveX/rxjs@54796b38a5 (2026-08-28). Data as JSON: /api/errors/f6c6893e9f392b5b. Report an issue: GitHub.