Unit Test

Being WinterCG compliant, we can use Request / Response classes to test an Elysia server.

Elysia provides the Elysia.handle method, which accepts a Web Standard Request and returns Response, simulating an HTTP Request.

Bun includes a built-in test runner that offers a Jest-like API through the bun:test module, facilitating the creation of unit tests.

Create test/index.test.ts in the root of project directory with the following:

// test/index.test.ts
import { describe, expect, it } from 'bun:test'
import { Elysia } from 'elysia'

describe('Elysia', () => {
    it('return a response', async () => {
        const app = new Elysia().get('/', () => 'hi')

        const response = await app
            .handle(new Request('http://localhost/'))
            .then((res) => res.text())

        expect(response).toBe('hi')
    })
})

// test/index.test.ts
import { describe, expect, it } from 'bun:test'
import { Elysia } from 'elysia'

describe('Elysia', () => {
    it('return a response', async () => {
        const app = new Elysia().get('/', () => 'hi')

        const response = await app
            .handle(new Request('http://localhost/'))
            .then((res) => res.text())

        expect(response).toBe('hi')
    })
})

Then we can perform tests by running bun test

bun test

bun test

New requests to an Elysia server must be a fully valid URL, NOT a part of a URL.

The request must provide URL as the following:

URL	Valid
http://localhost/user	✅
/user	❌

We can also use other testing libraries like Jest or testing library to create Elysia unit tests.

Eden Treaty test

We may use Eden Treaty to create an end-to-end type safety test for Elysia server as follows:

// test/index.test.ts
import { describe, expect, it } from 'bun:test'
import { Elysia } from 'elysia'
import { treaty } from '@elysiajs/eden'

const app = new Elysia().get('/hello', () => 'hi')

const api = treaty(app)

describe('Elysia', () => {
    it('return a response', async () => {
        const { data, error } = await api.hello.get()

        expect(response).toBe('hi')
    })
})

// test/index.test.ts
import { describe, expect, it } from 'bun:test'
import { Elysia } from 'elysia'
import { treaty } from '@elysiajs/eden'

const app = new Elysia().get('/hello', () => 'hi')

const api = treaty(app)

describe('Elysia', () => {
    it('return a response', async () => {
        const { data, error } = await api.hello.get()

        expect(response).toBe('hi')
    })
})

See Eden Treaty Unit Test for setup and more information.