Function spawnJest

e2e/runJest.ts:74–130

(
  dir: string,
  args: Array<string> = [],
  options: RunJestOptions = {},
  spawnAsync = false,
)

// Spawns Jest and returns either a Promise (if spawnAsync is true) or the completed child process
function spawnJest(
  dir: string,
  args: Array<string> = [],
  options: RunJestOptions = {},
  spawnAsync = false,
): execa.ExecaSyncReturnValue | execa.ExecaChildProcess {
  const isRelative = !path.isAbsolute(dir);

  if (isRelative) {
    dir = path.resolve(__dirname, dir);
  }

  const localPackageJson = path.resolve(dir, 'package.json');
  if (!options.skipPkgJsonCheck && !fs.existsSync(localPackageJson)) {
    throw new Error(dedent`
      Make sure you have a local package.json file at
        "${localPackageJson}".
      Otherwise Jest will try to traverse the directory tree and find the global package.json, which will send Jest into infinite loop.
    `);
  }
  const env: NodeJS.ProcessEnv = {
    ...process.env,
    // Prevent AI agent detection from leaking into child processes, which
    // would activate the AgentReporter and break output-dependent e2e tests.
    AI_AGENT: undefined,
    AUGMENT_AGENT: undefined,
    CLAUDECODE: undefined,
    CLAUDE_CODE: undefined,
    CODEX_SANDBOX: undefined,
    CODEX_THREAD_ID: undefined,
    CURSOR_AGENT: undefined,
    FORCE_COLOR: '0',
    GEMINI_CLI: undefined,
    GOOSE_PROVIDER: undefined,
    NO_COLOR: '1',
    OPENCODE: undefined,
    ...options.env,
  };

  if (options.nodeOptions) env['NODE_OPTIONS'] = options.nodeOptions;
  if (options.nodePath) env['NODE_PATH'] = options.nodePath;

  const spawnArgs = [JEST_PATH, ...args];
  const spawnOptions: execa.CommonOptions<string> = {
    cwd: dir,
    env,
    reject: false,
    stripFinalNewline: !options.keepTrailingNewline,
    timeout: options.timeout || 0,
  };

  return (spawnAsync ? execa : execa.sync)(
    process.execPath,
    spawnArgs,
    spawnOptions,
  );
}