react-native-navigation/src2/containers/ContainerRegistry.test.js

import _ from 'lodash';
import {AppRegistry, Text} from 'react-native';
import React, {Component} from 'react';
import renderer from 'react-test-renderer';

class MyContainer extends Component {
  render() {
    const txt = `Hello, ${_.get(this.props, 'name', 'World')}!`;
    return (
      <Text>{txt}</Text>
    );
  }
}

describe('ComponentRegistry', () => {
  let uut;

  beforeEach(() => {
    AppRegistry.registerComponent = jest.fn(AppRegistry.registerComponent);
    uut = require('./ContainerRegistry');
  });

  describe('registerContainer', () => {
    function getRegisteredComponentClassFromAppRegistry() {
      return AppRegistry.registerComponent.mock.calls[0][1]();
    }

    function renderRegisteredContainer(props) {
      const Container = getRegisteredComponentClassFromAppRegistry();
      return renderer.create(
        <Container screenId="screen1" {...props}/>
      );
    }

    it('registers container component by containerKey into AppRegistry', () => {
      expect(AppRegistry.registerComponent).not.toHaveBeenCalled();

      uut.registerContainer('example.MyContainer.key', () => MyContainer);

      expect(AppRegistry.registerComponent).toHaveBeenCalledTimes(1);
      expect(AppRegistry.registerComponent.mock.calls[0][0]).toEqual('example.MyContainer.key');
    });

    it('wraps the container', () => {
      uut.registerContainer('example.MyContainer', () => MyContainer);
      const tree = renderRegisteredContainer();
      expect(tree.toJSON().children).toEqual(['Hello, World!']);
    });

    it('passes props from wrapper into original container', () => {
      uut.registerContainer('example.MyContainer', () => MyContainer);
      const tree = renderRegisteredContainer({name: 'Daniel'});
      expect(tree.toJSON().children).toEqual(['Hello, Daniel!']);
    });

    it('injects and updates props into original container', () => {
      uut.registerContainer('example.MyContainer', () => MyContainer);

      const NavigationContainer = getRegisteredComponentClassFromAppRegistry();
      class TestParent extends Component { //eslint-disable-line
        constructor(props) {
          super(props);
          this.state = {};
        }

        render() {
          return (
            <NavigationContainer screenId="screen1" name={this.state.name}/>
          );
        }
      }

      let testParentRef = null;
      const tree = renderer.create(
        <TestParent ref={(r) => testParentRef = r}/>
      );

      expect(tree.toJSON().children).toEqual(['Hello, World!']);
      testParentRef.setState({name: 'Gandalf'});
      expect(tree.toJSON().children).toEqual(['Hello, Gandalf!']);
    });

    it('asserts has screenId as prop', () => {
      uut.registerContainer('example.MyContainer.key', () => MyContainer);
      const NavigationContainer = getRegisteredComponentClassFromAppRegistry();
      expect(() => {
        renderer.create(<NavigationContainer/>);
      }).toThrow(new Error('Screen example.MyContainer.key does not have a screenId!'));
    });
  });
});