Fastify comes with built-in support for fake http injection thanks to .

    To inject a fake http request, use the inject method:

    1. fastify
    2.   .inject({
    3.     method: String,
    4.     url: String,
    5.     query: Object,
    6.     payload: Object,
    7.     headers: Object
    8.   })
    9.   .then(response => {
    10.     // your tests
    11.   })
    12.   .catch(err => {
    13.     // handle error
    14.   })

    Async await is supported as well!

    1. try {
    2.   const res = await fastify.inject({ method: String, url: String, payload: Object, headers: Object })
    3.   // your tests
    4. } catch (err) {
    5.   // handle error
    6. }

    Example:

    app.js

    test.js

    1. const tap = require('tap')
    3. tap.test('GET `/` route', t => {
    4.   t.plan(4)
    8.   // At the end of your tests it is highly recommended to call `.close()`
    9.   // to ensure that all connections to external services get closed.
    10.   t.tearDown(() => fastify.close())
    12.   fastify.inject({
    13.     method: 'GET',
    14.     url: '/'
    15.   }, (err, response) => {
    16.     t.error(err)
    17.     t.strictEqual(response.statusCode, 200)
    18.     t.strictEqual(response.headers['content-type'], 'application/json; charset=utf-8')
    19.     t.deepEqual(JSON.parse(response.payload), { hello: 'world' })
    20.   })
    21. })

    Example:

    Uses app.js from the previous example.

    test-listen.js (testing with )

    1. const tap = require('tap')
    2. const request = require('request')
    3. const buildFastify = require('./app')
    5. tap.test('GET `/` route', t => {
    6.   t.plan(5)
    7.   const fastify = buildFastify()
    11.   fastify.listen(0, (err) => {
    12.     t.error(err)
    14.     request({
    15.       method: 'GET',
    16.       url: 'http://localhost:' + fastify.server.address().port
    17.     }, (err, response, body) => {
    18.       t.error(err)
    19.       t.strictEqual(response.statusCode, 200)
    20.       t.strictEqual(response.headers['content-type'], 'application/json; charset=utf-8')
    21.       t.deepEqual(JSON.parse(body), { hello: 'world' })
    22.     })
    23.   })
    24. })

    test-ready.js (testing with SuperTest)

    • Isolate your test by passing the {only: true} option
    1. test('should ...', {only: true}, t => ...)
    • Run tap using npx
    1. > npx tap -O -T --node-arg=--inspect-brk test/<test-file.test.js>
    • -O specifies to run tests with the only option enabled
    • -T specifies not to timeout (while you're debugging)
    • —node-arg=—inspect-brk will launch the node debugger
    • In VS Code, create and launch a Node.js: Attach debug configuration. No modification should be necessary.Now you should be able to step through your test file (and the rest of fastify) in your code editor.