crashOverlay.js

  var iframe = window.document.createElement('iframe');
  applyStyles(iframe, iframeStyle);
  iframeReference = iframe;
  iframe.onload = function() {
    if (iframeReference == null) {
      return;
    }
    var w = iframeReference.contentWindow;
    var document = iframeReference.contentDocument;

    var _createOverlay = createOverlay(
      document,
      name,
      message,
      resolvedFrames,
      CONTEXT_SIZE,
      currReferenceIndex + 1,
      errorReferences.length,
      function(offset) {
        switchError(offset);
      },
      function() {
        unmount();
      }
    ),
      overlay = _createOverlay.overlay,
      additional = _createOverlay.additional;

    if (w != null) {
      w.onkeydown = function(event) {
        keyHandler(
          function(type) {
            return shortcutHandler(type);
          },
          event
        );
      };
    }
    injectCss(iframeReference.contentDocument, css);
    if (document.body != null) {
      document.body.appendChild(overlay);
    }
    additionalReference = additional;
  };
  window.document.body.appendChild(iframe);
}

function renderErrorByIndex(index) {
  currReferenceIndex = index;

  var _getErrorRecord = getErrorRecord(errorReferences[index]),
    error = _getErrorRecord.error,
    unhandledRejection = _getErrorRecord.unhandledRejection,
    enhancedFrames = _getErrorRecord.enhancedFrames;

  if (unhandledRejection) {
    render(
      'Unhandled Rejection (' + error.name + ')',
      error.message,
      enhancedFrames
    );
  } else {
    render(error.name, error.message, enhancedFrames);
  }
}

function switchError(offset) {
  var nextView = currReferenceIndex + offset;
  if (nextView < 0 || nextView >= errorReferences.length) {
    return;
  }
  renderErrorByIndex(nextView);
}

function disposeCurrentView() {
  if (iframeReference === null) {
    return;
  }
  window.document.body.removeChild(iframeReference);
  iframeReference = null;
  additionalReference = null;
}

function unmount() {
  disposeCurrentView();
  drain();
  errorReferences = [];
  currReferenceIndex = -1;
}

function crash(error) {
  var unhandledRejection = arguments.length > 1 && arguments[1] !== undefined
    ? arguments[1]
    : false;

  if (module.hot && typeof module.hot.decline === 'function') {
    module.hot.decline();
  }
  consume(error, unhandledRejection, CONTEXT_SIZE)
    .then(function(ref) {
      errorReferences.push(ref);
      if (iframeReference !== null && additionalReference !== null) {
        updateAdditional(
          iframeReference.contentDocument,
          additionalReference,
          currReferenceIndex + 1,
          errorReferences.length,
          function(offset) {
            switchError(offset);
          }
        );
      } else {
        if (errorReferences.length !== 1) {
          throw new Error('Something is *really* wrong.');
        }
        renderErrorByIndex((currReferenceIndex = 0));
      }
    })
    .catch(function(e) {
      console.log('Could not consume error:', e);
    });
}

function shortcutHandler(type) {
  switch (type) {
    case SHORTCUT_ESCAPE: {
      unmount();
      break;
    }
    case SHORTCUT_LEFT: {
      switchError(-1);
      break;
    }
    case SHORTCUT_RIGHT: {
      switchError(1);
      break;
    }
  }
}

function inject() {
  registerUnhandledError(window, function(error) {
    return crash(error);
  });
  registerUnhandledRejection(window, function(error) {
    return crash(error, true);
  });
  registerShortcuts(window, shortcutHandler);
  registerStackTraceLimit();
}

function uninject() {
  unregisterStackTraceLimit();
  unregisterShortcuts(window);
  unregisterUnhandledRejection(window);
  unregisterUnhandledError(window);
}

inject();
if (module.hot && typeof module.hot.dispose === 'function') {
  module.hot.dispose(function() {
    uninject();
  });
}