Japa Test Mail using trap() function doesn't stop email nor make assertions

[mikesaintsg]

@adonisjs/core ^5.4.2
@adonisjs/mail ^7.2.4
japa ^4.0.0

Tried to test this simple email to see if it works but no luck.

I do have this hooked up to mailtrap and it is receiving the emails, so I'm not too sure why the trap isn't working:

I made sure to plan for the assertions and nothing runs:

start/routes.ts

import Route from '@ioc:Adonis/Core/Route'
import Mail from '@ioc:Adonis/Addons/Mail'

Route.get('/', async ({ view }) => {
  await Mail.send((message) => {
    message
      .from('[email protected]')
      .to('[email protected]')
      .subject('Welcome to my app')
      .text('emails/welcome')
  })

  return view.render('welcome')
})

tests/example.spec.ts

import test from 'japa'
import supertest from 'supertest'
import Mail from '@ioc:Adonis/Addons/Mail'

const BASE_URL = `http://${process.env.HOST}:${process.env.PORT}`

test.group('Welcome', async (group) => {
  test('ensure home page works', async (assert) => {
    assert.plan(3)

    await supertest.agent(BASE_URL).get('/').expect(200)

    Mail.trap((message) => {
      assert.deepEqual(message.to, [
        {
          address: 'should fail',
        },
      ])
      assert.deepEqual(message.from, {
        address: 'should fail',
      })
      assert.equal(message.subject, 'should fail')
    })
  })

  group.afterEach(() => {
    Mail.restore()
  })
})

japaFile.ts

import 'reflect-metadata'
import { configure } from 'japa'
import sourceMapSupport from 'source-map-support'
import { Ignitor } from '@adonisjs/core/build/standalone'

process.env.NODE_ENV = 'testing'
sourceMapSupport.install({ handleUncaughtExceptions: false })

const ignitor = new Ignitor(__dirname)

export const httpServer = ignitor.httpServer()
export const application = httpServer.application

application.switchEnvironment('test')

configure({
  files: ['tests/**/*.spec.ts'],
  before: [
    async () => {
      await httpServer.start()
    },
  ],
})

[thetutlage]

It because you are trapping the email after making a request to the server.

This is how you are doing it

    await supertest.agent(BASE_URL).get('/').expect(200)

    Mail.trap((message) => {
      assert.deepEqual(message.to, [
        {
          address: 'should fail',
        },
      ])
      assert.deepEqual(message.from, {
        address: 'should fail',
      })
      assert.equal(message.subject, 'should fail')
    })
  })

This is how it should be structured

    // First trap the email
    Mail.trap((message) => {
      assert.deepEqual(message.to, [
        {
          address: 'should fail',
        },
      ])
      assert.deepEqual(message.from, {
        address: 'should fail',
      })
      assert.equal(message.subject, 'should fail')
    })
  })

  // Then make the request
  await supertest.agent(BASE_URL).get('/').expect(200)

[mikesaintsg]

Thank you Harminder, it works, you're the best!

Played around with it a bit and noted that since it's in a callback, it's best to wrap the assertions in a try/catch block and send any errors to the done function in order to report those actual assertion errors. Otherwise you just get a 500 error from the supertest expectation, or a timeout error if the supertest expectation isn't called.

test('GET "/" welcome', async (assert, done) => {
    Mail.trap((message) => {
      try {
        assert.deepEqual(message.to, [
          {
            address: '[email protected]',
          },
        ])

        assert.deepEqual(message.from, {
          address: '[email protected]',
        })

        assert.equal(message.subject, 'Welcome to my ap')

        done()
      } catch (e) {
        done(e)
      }
    })
    await supertest.agent(BASE_URL).get('/').expect(200)
})