javascript - 试图模拟 API 响应延迟 : Cannot read property 'then' of undefined

Question

在我的 React 应用程序中，我试图伪造模拟 API 响应的延迟

Uncaught TypeError: Cannot read property 'then' of undefined

createDraft() {
  // Post to Mock API
  const newDraft = {
    name: this.state.draftName,
    created_by: this.props.user,
    created: getDate()
  };

  /* ERROR HERE */
  this.props.create(newDraft).then((res) => {
    console.log(' res', res);
    // Display loading spinner while waiting on Promise

    // Close modal and redirect to Draft Summary view
    this.props.closeModal();
  });
}

Action :

export const create = newDraft => dispatch => all()
  .then(() => setTimeout(() => {
    dispatch({
      type: CREATE,
      newDraft
    });
    return 'Draft created!';
  }, 2000))
  .catch(() => {
    dispatch({
      type: REQUEST_ERROR,
      payload: apiErrors.BAD_REQUEST
    });
  });

连通区域:

const mapDispatchToProps = dispatch => ({
  create: (newDraft) => { dispatch(create(newDraft)); }
});

export const CreateDraftModalJest = CreateDraftModal;

export default connect(cleanMapStateToProps([
  'user'
]), mapDispatchToProps)(CreateDraftModal);

也试过同样的结果

function DelayPromise(t) {
  return new Promise(((resolve) => {
    setTimeout(resolve, t);
  }));
}

export const create = newDraft => dispatch => all()
  .then(DelayPromise(2000))
  .then(() => {
    console.log('created called', newDraft);
    dispatch({
      type: CREATE,
      newDraft
    });
  })
  .then(() => 'Draft created!')
  .catch(() => {
    dispatch({
      type: REQUEST_ERROR,
      payload: apiErrors.BAD_REQUEST
    });
  });

Answer 1

有可能您的 this.props.create() 操作创建者未绑定(bind)调度，因此未按预期返回 promise 。

你是否正确使用了 react-redux connect()？

编辑:

您的 mapDispatchToProps 没有返回 promise 。改为这样做:

const mapDispatchToProps = dispatch => ({
  create: (newDraft) => dispatch(create(newDraft)),
});