Part 4 – Seeds

We've fixed our GET and POST route handlers, but our app starts our empty. We can use the seeds hook to seed Mirage with some initial data.

Copy these lines into your server definition:

import { createServer, Model } from "miragejs"

export default function () {
  createServer({
    models: {
      reminder: Model,
    },

    seeds(server) {
      server.create("reminder", { text: "Walk the dog" })
      server.create("reminder", { text: "Take out the trash" })
      server.create("reminder", { text: "Work out" })
    },

    routes() {
      this.get("/api/reminders", (schema) => {
        return schema.reminders.all()
      })

      this.post("/api/reminders", (schema, request) => {
        let attrs = JSON.parse(request.requestBody)

        return schema.reminders.create(attrs)
      })
    },
  })
}

Once you save, you should see the app reload with these three Reminders as its initial data.

The server.create function lets us create new reminders in Mirage's data layer. IDs are automatically assigned, just like when we call reminders.create() in route handlers.

Try using the app to create a fourth reminder to "Buy groceries". You should see the new Reminder get an ID of 4 if you inspect the response. And, if you navigate to the About page and back, you'll see all four Reminders show up just as you'd expect.

Mirage's seeds are loaded on initialization and work right alongside any data that's created or modified from route handlers as you interact with your app in the browser, so all your API data remains consistent.

Takeaways

  • Use the seeds hook and server.create to create initial data for your server