Verify an automation harness against itself A test browser that quietly looks wrong is a test suite that quietly gets challenged. answers one question about a harness: does its JavaScript story agree with itself and with what the network layer saw? It measures; it does not modify the browser and ships no evasions or profiles. Node 22 or newer. Zero runtime dependencies, so it adds nothing to an existing Playwright or Puppeteer install. Against a Page you already have works with any object exposing . Playwright and Puppeteer objects both qualify, so the harness under test is the harness being…