Media & Devices
Mock microphone and camera input, test WebRTC calls, and assert that sound is actually playing.
Recipes for the hard-to-test web
Microphone input, inertial maps, vanishing toasts, passkeys, flaky tests. Use-case-driven recipes for everything your test framework doesn't do out of the box.
What is this?
Section titled “What is this?”Modern test frameworks like Playwright are excellent at clicking buttons and asserting text. But real applications do more than that: they listen to your microphone, render maps you pan with a flick, flash toasts that vanish before your assertion runs, and authenticate with passkeys.
Every recipe here starts from a use case — “I need to test voice input”, “I need to verify an email was sent” — explains why it’s hard, and gives you working code.
Complex UI
Maps with inertial panning, canvas charts, vanishing toasts, IME composition — UIs that don’t speak DOM.
Auth & Identity
Passkeys / WebAuthn with a virtual authenticator, and TOTP two-factor login without a phone.
Beyond the Browser
Emails, PDFs, and the clipboard — the parts of a user journey that leave the page.
Strategy & Maintenance
Auto-repair flaky tests, push E2E checks down to unit tests, and measure use-case coverage.
Use-case driven
No framework tours. Each recipe solves one concrete problem you can search for.
Need this working in your product?
Section titled “Need this working in your product?”These recipes come from real consulting work: taking UIs and pipelines that “can’t be tested” and making them testable. If your team is stuck on one of these problems — or something weirder — I take on consulting and contract work at untestable.dev.
Start with a featured recipe
Section titled “Start with a featured recipe”Mock microphone inputStream real audio files into getUserMedia() on Chromium, Firefox and WebKit.
Test map UIs with inertial panningPan a map by an exact pixel distance using pixel-based closed-loop control.
Catch toasts and flickerAssert on UI that appears and disappears faster than your assertions.