capture JavaScript errors (useful for debugging Safari webviews - e.g., Chrome for iOS)

capture-errors-safari-ios-webview.js

/**
 * Hijacks `window.onerror` for debugging Chrome for iOS (WebView) via `chrome://inspect`.
 *
 * @returns {string|undefined}
 */
window.onerror = function(message, url, lineNumber, columnNumber, error) {
  console.error(
    [
      ['Error message:', message].join(' '),
      ['URL:', url].join(' '),
      ['Line:', lineNumber].join(' '),
      ['Column:', columnNumber].join(' '),
      ['Full error:', error].join(' ')
    ].join('\n')
  );
  return false;
};