Function formatHandleErrors

packages/jest-core/src/collectHandles.ts:168–212

(
  errors: Array<Error>,
  config: Config.ProjectConfig,
)

}

export function formatHandleErrors(
  errors: Array<Error>,
  config: Config.ProjectConfig,
): Array<string> {
  const stacks = new Map<string, {stack: string; names: Set<string>}>();

  for (const err of errors) {
    const formatted = formatExecError(
      err,
      config,
      {noStackTrace: false},
      undefined,
      true,
    );

    // E.g. timeouts might give multiple traces to the same line of code
    // This hairy filtering tries to remove entries with duplicate stack traces

    const ansiFree: string = stripAnsi(formatted);
    const match = ansiFree.match(/\s+at(.*)/);
    if (!match || match.length < 2) {
      continue;
    }

    const stackText = ansiFree.slice(ansiFree.indexOf(match[1])).trim();

    const name = ansiFree.match(/(?<=● {2}).*$/m);
    if (name == null || name.length === 0) {
      continue;
    }

    const stack = stacks.get(stackText) || {
      names: new Set(),
      stack: formatted.replace(name[0], '%%OBJECT_NAME%%'),
    };

    stack.names.add(name[0]);

    stacks.set(stackText, stack);
  }

  return [...stacks.values()].map(({stack, names}) =>
    stack.replace('%%OBJECT_NAME%%', [...names].join(',')),
  );
}