Function getErrorMessage

actions/setup/js/error_helpers.cjs:26–44

* Safely extract an error message from an unknown error value. * Handles Error instances, objects with message properties, and other values. * * When the extracted message looks like an HTML page (e.g. GitHub's "Unicorn" * 504 error page), it is replaced with a concise human-readable description

(error)

 * @returns {string} The error message as a string
 */
function getErrorMessage(error) {
  // prettier-ignore
  const errorAsAny = /** @type {any} */ (error);
  let message;
  if (error instanceof Error) {
    message = error.message;
  } else if (error && typeof error === "object" && "message" in error && typeof error.message === "string") {
    message = error.message;
  } else {
    message = String(error);
  }

  if (isHtmlContent(message)) {
    const status = errorAsAny != null && typeof errorAsAny.status === "number" ? errorAsAny.status : null;
    return status != null ? `GitHub returned an unexpected HTML response (HTTP ${status})` : "GitHub returned an unexpected HTML response";
  }

  return message;
}

/**
 * Check if an error is due to a locked issue/PR/discussion.