FixtureKit
Turn TypeScript interfaces into realistic mock data
50 followers
Turn TypeScript interfaces into realistic mock data
50 followers
FixtureKit is a free, entirely browser-based tool that uses semantic inference to turn TypeScript interfaces or Zod schemas into realistic mock data. Copy as raw TS, JSON, MSW handlers, or Playwright route mocks. Features an Adversarial Mode to stress-test your UI.
Hey Product Hunt! 👋
I built FixtureKit because I kept wasting the first 20 minutes of
every project writing the same mock objects by hand. mockUser,
mockProduct, mockOrder -- all manually typed, all instantly outdated
the moment I changed the interface.
Every TypeScript dev knows this pain. Your types are perfect, but
your test data is a mess of "string", "string", 123.
The thing that bothered me most was that other tools either require
installation, send your schema to a server, or just fill everything
with meaningless placeholders. I wanted something that runs in the
browser, understands what field names mean, and gives you something
that actually looks real.
So FixtureKit infers from the field name -- email gets a real email,
price gets a real number, createdAt gets an ISO date. It's
deterministic so the output is safe to commit. And it supports MSW
and Playwright output so it plugs into the testing stack most
TypeScript teams already use.
Would love to hear what schema patterns break it -- that's the most
useful feedback I can get right now.
This solves one of those small dev chores that somehow eats half an afternoon.
I like that it starts from the schema I already have, instead of making me set up Faker rules from scratch. The Playwright and MSW exports are probably where I’d use it most, because mock data is much more useful when it can drop straight into tests or local dev.
Adversarial Mode is a nice idea too. Tables, forms, and profile screens always look fine until one weird string, empty value, or unsafe input shows up.
@eliot_argy Thanks Eliot! You nailed it -- setting up Faker rules from scratch for every single project was exactly the headache that pushed me to build this. I'm really glad the MSW/Playwright exports resonate with you. And totally agreed on Adversarial Mode; it’s amazing how quickly a 'perfect' UI breaks when a user decides to input a 500-character string or a null value 😂 Let me know if you run into any edge-case schemas it struggles with!
@eliot_argy If you have a TypeScript schema that breaks FixtureKit, I'd love to see it.
Update: schemas are now shareable as links.
Here's an Order fixture you can open directly:
https://fixture-kit.vercel.app/#JTdCJTIy...
Click "Copy link" on any fixture to share yours.
This is super helpful actually, i'm a SWE and this tool helps me in local development, thanks.
@therayess Thanks so much, Ammar! Really glad to hear it’s useful for your local dev workflow. If you don't mind me asking, are you mostly pasting in TypeScript interfaces or Zod schemas for your day-to-day work?
@therayess Thanks! If you have a TypeScript schema that breaks FixtureKit, I'd love to see it.