Define factories to clean up fake data generation in tests
npm install @stackup/factory$ yarn add @stackup/factory --dev
First, you'll need to define a factory:
``javascript
import { factory } from "@stackup/factory";
const UserFactory = factory({
id: 1,
name: "Rick",
});
`
Great, now to use that factory, just call the build method:
`javascript`
UserFactory.build();
// { id: 1, name: "Rick" }
You can override some of the properties, too:
`javascript`
UserFactory.build({ name: "Ray" });
// { id: 1, name: "Ray" }
Generate an array:
`javascript`
UserFactory.array(2).build();
// [
// { id: 1, name: "Rick" },
// { id: 1, name: "Rick" }
// ]
Your factories can reuse other factories:
`javascript
const ProfileFactory = factory({
user: UserFactory,
friends: UserFactory.array(2),
});
ProfileFactory.build();
// {
// user: { id: 1, name: "Rick" },
// friends: [{ id: 1, name: "Rick" }, { id: 1, name: "Rick" }]
// }
`
Need something to be unique?
`javascript
import { sequence } from "@stackup/factory";
const UserFactory = factory({
email: sequence((n) => ${n}@example.com),
});
UserFactory.build();
// { email: "78@example.com" }
UserFactory.build();
// { email: "79@example.com" }
`
Want random data?
`javascript
import { random } from "@stackup/factory";
const UserFactory = factory({
name: random((chance) => chance.name()),
});
UserFactory.build();
// { name: "Leona Floyd" }
UserFactory.build();
// { name: "Max Copeland" }
`
If you're snapshot testing, random data will break your tests. In that case, you
can generate data deterministically:
`javascript
UserFactory.fixture();
// { name: "Abe" }
UserFactory.fixture();
// { name: "Abe" }
``