How to test and monitor your APIs with Playwright

Microsoft's Playwright can be used for both end-to-end testing and API testing, enabling control over headless browsers and checking essential user flows, as well as controlling HTTP-based APIs. A demo GraphQL API is used to illustrate how Playwright can be used for API testing, with a test case that sends a POST request with a query in the request body to retrieve data from the API. The test checks if the response contains expected data and logs the entire response. To add assertions, the test uses playwright's snapshot tool to compare the response to an initial JSON file or to filter the response. Continuous monitoring of APIs can be achieved using Playwright and Checkly, a monitoring service that allows for dynamic notification settings, retries, and setup scripts, making it cheaper than browser checks.