trait.mdx

title
Trait

import { Callout } from "nextra/components";

Managing Multiple Properties and Variables Using Keys

By using .trait, you can manage multiple properties and variables using keys. Within .trait, you can define properties, variables, and after hooks.

const userFactory = factory
  .define({
    props: {
      role: () => "guest",
      isAdmin: () => false,
    },
    vars: {
      greeting: () => "Hi",
    },
  })
  .traits({
    admin: {
      props: {
        role: () => "admin",
        isAdmin: () => true,
      },
      vars: {
        greeting: () => "Hello",
      },
      after: () => {
        console.log("Admin created");
      },
    },
  });

// To use a trait, specify the key with `use`
await userFactory.use((t) => t.admin).build();

You can also define multiple traits. In the example below, three traits are defined.

const userFactory = factory
  .define({
    props: {
      name: () => "John",
      role: () => "guest",
      isAdmin: () => false,
    },
    vars: {},
  })
  .traits({
    employee: {
      props: {
        role: () => "employee",
        isAdmin: () => false,
      },
    },
    admin: {
      props: {
        role: () => "admin",
        isAdmin: () => true,
      },
    },
  })
  .traits({
    maskedName: {
      props: {
        name: () => "***",
      },
    },
  });

You can use multiple .trait as well. The last applied trait takes precedence.

await userFactory
  .use((t) => t.employee)
  .use((t) => t.admin)
  .use((t) => t.maskedName)
  .build(); // 👉 { name: "***", role: "admin", isAdmin: true }