Puppeteer wait for XHR calls

puppeteer-wait-network-xhr.ts

function waitForAjaxCalls(page: Page) {
  const task = new Task<void>();

  let _expectedCount = Infinity;
  let processedCalls = 0;

  const handler = (req: HTTPRequest) => {
    if (req.method() !== 'POST') {
      return;
    }

    if (req.response().ok()) {
      ++processedCalls;
    } else {
      task.reject(new InternalServerErrorException('Failed to load data'));
    }

    if (processedCalls >= _expectedCount) {
      task.resolve();
    }
  };

  page.on('requestfinished', handler);

  return (expectedCount: number, timeLimit: number) => {
    _expectedCount = expectedCount;
    if (processedCalls >= expectedCount) {
      task.resolve();
    }

    const timeoutTask = new Task<void>();
    const timeoutId = setTimeout(() => {
      timeoutTask.reject(new InternalServerErrorException(`Timeout for data load`));
    }, timeLimit);

    return Promise.race([task, timeoutTask]).finally(() => {
      clearTimeout(timeoutId);
      page.off('requestfinished', handler);
    });
  };
}

// Usage
const callInterceptor = waitForAjaxCalls(page);
const expectedAjaxCallCounts = 10; // image some async action
await monthsAjaxCallInterceptor(expectedAjaxCallCounts, 10 * 1000); // 10 seconds timeout