将 react-intl 对象注入到安装的 Enzyme 组件中进行测试

Question

编辑： 已解决！向下滚动查看答案

在我们的组件测试中，我们需要它们在没有 <IntlProvider /> 父包装器的情况下访问 react-intl context. The problem is that we are mounting single components (with Enzyme's mount())。这可以通过包装提供者来解决，但是 root 指向 IntlProvider 实例而不是 CustomComponent。

Testing with React-Intl: Enzyme 文档仍然是空的。

class CustomComponent extends Component {
  state = {
    foo: 'bar'
  }

  render() {
    return (
      <div>
        <FormattedMessage id="world.hello" defaultMessage="Hello World!" />
      </div>
    );
  }
}

标准测试用例（期望）（酶 + 摩卡 + 柴）

// This is how we mount components normally with Enzyme
const wrapper = mount(
  <CustomComponent
    params={params}
  />
);

expect( wrapper.state('foo') ).to.equal('bar');

但是，由于我们的组件使用 FormattedMessage 作为 react-intl 库的一部分，所以当运行上述代码时，我们会收到此错误：

Uncaught Invariant Violation: [React Intl] Could not find required `intl` object. <IntlProvider> needs to exist in the component ancestry.

用IntlProvider

包装它

const wrapper = mount(
  <IntlProvider locale="en">
    <CustomComponent
      params={params}
    />
  </IntlProvider>
);

这为 CustomComponent 提供了它要求的 intl 上下文。但是，当尝试进行如下测试断言时：

expect( wrapper.state('foo') ).to.equal('bar');

引发以下异常：

AssertionError: expected undefined to equal ''

这当然是因为它试图读取 IntlProvider 而不是我们的 CustomComponent 的状态。

尝试访问 `CustomComponent`

我已尝试以下方法无济于事：

const wrapper = mount(
  <IntlProvider locale="en">
    <CustomComponent
      params={params}
    />
  </IntlProvider>
);


// Below cases have all individually been tried to call `.state('foo')` on:
// expect( component.state('foo') ).to.equal('bar');

const component = wrapper.childAt(0); 
> Error: ReactWrapper::state() can only be called on the root

const component = wrapper.children();
> Error: ReactWrapper::state() can only be called on the root

const component = wrapper.children();
component.root = component;
> TypeError: Cannot read property 'getInstance' of null

问题是：我们如何使用 intl 上下文挂载 CustomComponent，同时仍然能够对我们的 CustomComponent 执行 "root" 操作?

Answer 1

我创建了一个辅助函数来修补现有的酶 mount() 和 shallow() 函数。我们现在在所有使用 React Intl 组件的测试中使用这些辅助方法。

您可以在这里找到要点：https://gist.github.com/mirague/c05f4da0d781a9b339b501f1d5d33c37

为了保持数据的可访问性，下面是代码的简要说明：

helpers/intl-test.js

/**
 * Components using the react-intl module require access to the intl context.
 * This is not available when mounting single components in Enzyme.
 * These helper functions aim to address that and wrap a valid,
 * English-locale intl context around them.
 */

import React from 'react';
import { IntlProvider, intlShape } from 'react-intl';
import { mount, shallow } from 'enzyme';

const messages = require('../locales/en'); // en.json
const intlProvider = new IntlProvider({ locale: 'en', messages }, {});
const { intl } = intlProvider.getChildContext();

/**
 * When using React-Intl `injectIntl` on components, props.intl is required.
 */
function nodeWithIntlProp(node) {
  return React.cloneElement(node, { intl });
}

export default {
  shallowWithIntl(node) {
    return shallow(nodeWithIntlProp(node), { context: { intl } });
  },

  mountWithIntl(node) {
    return mount(nodeWithIntlProp(node), {
      context: { intl },
      childContextTypes: { intl: intlShape }
    });
  }
};

自定义组件

class CustomComponent extends Component {
  state = {
    foo: 'bar'
  }

  render() {
    return (
      <div>
        <FormattedMessage id="world.hello" defaultMessage="Hello World!" />
      </div>
    );
  }
}

CustomComponentTest.js

import { mountWithIntl } from 'helpers/intl-test';

const wrapper = mountWithIntl(
  <CustomComponent />
);

expect(wrapper.state('foo')).to.equal('bar'); // OK
expect(wrapper.text()).to.equal('Hello World!'); // OK

将 react-intl 对象注入到安装的 Enzyme 组件中进行测试

Injecting react-intl object into mounted Enzyme components for testing

reactjs

enzyme

react-intl

尝试访问 `CustomComponent`

将 react-intl 对象注入到安装的 Enzyme 组件中进行测试

Injecting react-intl object into mounted Enzyme components for testing

reactjs

enzyme

react-intl

尝试访问 CustomComponent

尝试访问 `CustomComponent`