Foo Class — react Architecture

Source Code

packages/react-reconciler/src/__tests__/ReactIncrementalScheduling-test.js lines 150–181

    class Foo extends React.Component {
      state = {tick: 0};

      componentDidMount() {
        Scheduler.log(
          'componentDidMount (before setState): ' + this.state.tick,
        );
        this.setState({tick: 1});
        // We're in a batch. Update hasn't flushed yet.
        Scheduler.log('componentDidMount (after setState): ' + this.state.tick);
      }

      componentDidUpdate() {
        Scheduler.log('componentDidUpdate: ' + this.state.tick);
        if (this.state.tick === 2) {
          Scheduler.log(
            'componentDidUpdate (before setState): ' + this.state.tick,
          );
          this.setState({tick: 3});
          Scheduler.log(
            'componentDidUpdate (after setState): ' + this.state.tick,
          );
          // We're in a batch. Update hasn't flushed yet.
        }
      }

      render() {
        Scheduler.log('render: ' + this.state.tick);
        instance = this;
        return <span prop={this.state.tick} />;
      }
    }