cgcardona

Notes from the 'Testing Ember Apps' session

Speaker

Jo Liss

Part 1 Full stack integration tests

capybara

  • 'Selenium for Rails'
  • Performance issues are a problem
  • Powerful but clunky
  • Strategy: ONly test every model once DB-to-DOM, read and write
  • Move finer-grained tests to client side

Part 2 Client side integration tests

The idea is to limit the architectural complexity. You have no back end. You have no DB. Test are run completely on the client.

konacha

  • Rails gem pachaging
  • Mocha.js testing framework +
  • Chai.js

Mocha + Chai

Mocha is a testing framework but it doesn't do assertions so you combine it with Chai. All test run in an i-frame by default and it's really fast.

It's very helpful to see it visually.

Konacha

Why is it fast?

  • No page loads
  • 100% asynchronous
  • No stack. The most expensive thing is the DOM manipulation that Ember does

Unit vs Integration

Lot of simple layers ==> integration tests win.

Ember setup

No 'official' support for testing. So we wing it!

Router

AppRouter.reopen location: 'none' beforeEach: ->

Konacha by default clears out the body. Ember automatically schedules run loops with setTimeout. That's bad for reliable tests.

Model Fixtures

Client-side fixtures

  • easy
  • goes out os sync with backend
  • fragile
  • server-side computed attributes

Server-side fixtures

rake test:fixtures

  1. Write fixtures to DB
  2. Generate JSOn to fixtures.js. Load through RESTAdapter
  • Covers models, serializers, adapters
  • Easy to maintain
  • Usability
  • Complex to set up

Bonus: JS-driven?

Capybara but in Javascript?

Questions

Q: with sinatra do you see opportunity for TTD

A: Not quite TDD but continuous. When working with Konacha I wrote tests as I went.

Q: Can you test views in isolation

A: it's really tricky to instantiate a view... It's too 'unit testy'. It might be possible

Comment: We use 'Rosie' for Javascript factories. Have you tried VCR for server side things? It's a Ruby library that will make the requests. We set up the tests against a live production server.

Q: A lot of bugs come from asynchronicity. Have you tried to test that specifically?

A: No I haven't. My hope is that a lot of these bugs dissapear. Mocha allows for asynchronous tests where you set a call back for when your test is complete.

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Published

15 February 2013

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