Function installMockBrowserRuntime

packages/scheduler/src/__tests__/Scheduler-test.js:57–174

()

  });

  function installMockBrowserRuntime() {
    let hasPendingMessageEvent = false;
    let isFiringMessageEvent = false;
    let hasPendingDiscreteEvent = false;
    let hasPendingContinuousEvent = false;

    let timerIDCounter = 0;
    // let timerIDs = new Map();

    let eventLog = [];

    let currentTime = 0;

    global.performance = {
      now() {
        return currentTime;
      },
    };

    // Delete node provide setImmediate so we fall through to MessageChannel.
    delete global.setImmediate;

    global.setTimeout = (cb, delay) => {
      const id = timerIDCounter++;
      log(`Set Timer`);
      // TODO
      return id;
    };
    global.clearTimeout = id => {
      // TODO
    };

    const port1 = {};
    const port2 = {
      postMessage() {
        if (hasPendingMessageEvent) {
          throw Error('Message event already scheduled');
        }
        log('Post Message');
        hasPendingMessageEvent = true;
      },
    };
    global.MessageChannel = function MessageChannel() {
      this.port1 = port1;
      this.port2 = port2;
    };

    function ensureLogIsEmpty() {
      if (eventLog.length !== 0) {
        throw Error('Log is not empty. Call assertLog before continuing.');
      }
    }
    function advanceTime(ms) {
      currentTime += ms;
    }
    function resetTime() {
      currentTime = 0;
    }