笑話和酵素| 在componentDidMount中測試PropTypes函數

Question

我的組件中有此代碼，該代碼將listUsers作為必需的PropType函數。 我想測試在componentDidMount() ，它應該只被調用一次。

組件代碼：

   static propTypes = {
    securityMode: PropTypes.string.isRequired,
    listUsers: PropTypes.func.isRequired
  };

  componentDidMount() {
    const { listUsers } = this.props;
    listUsers();
  }

    onCreateUserSucess= response => {
    this.setState({ isCreateUserModalOpen: false });
    const { listUsers, notify } = this.props;
    listUsers();
    this.closeCreateUserModal();
    notify({
      title: 'Created User',
      message: `User ${response.username} was added to group: ${response.group}`,
      status: STATUS.success,
      dismissible: true,
      dismissAfter: 3000
    });
  };

我收到一個錯誤消息，說spyOn僅適用於函數。 有人可以幫我測試一下。 componentDidMount和onCreateUserSucess 。 我什至嘗試模擬功能，但總是失敗。

Answer 1

測試componentDidMount非常簡單。 假設您在上面創建的組件稱為UsersDisplayer 。

class UsersDisplayer extends Component {
   constructor(props) {
      // ...
   }

   // The code above goes here.
}

為了測試listUsers函數是否運行，您應該執行以下操作：

// Import React, shallow and UsersDisplayer at the top.

describe('<UsersDisplayer />', () => {
   let usersDisplayerWrapper;
   let listUsers;

   beforeEach(() => {
      listUsers = jest.fn();

      usersDisplayerWrapper = <UsersDisplayer listUsers={listUsers} />;
   });

   describe('componentDidMount', () => {
      it('calls listUsers props function', () => {
          // The `componentDidMount` lifecycle method is called during the rendering of the component within the `beforeEach` block, that runs before each test suites.
         expect(listUsers).toHaveBeenCalled();
      });
   });

   describe('onCreateUserSucess', () => {
      it('calls listUsers props function', () => {
         // Create a dummy `response` data that will be passed to the function.
         const response = {
            username: 'username',
            group: 'group'
         };

         // Simply just call the function of the instance.
         usersDisplayerWrapper.instance().onCreateUserSucess(response);

         expect(listUsers).toHaveBeenCalled();
      });
   });
});