Testing Models

Unit testing methods and computed properties follows previous patterns shown in Unit Testing Basics because DS.Model extends Ember.Object.

Ember Data Models can be tested using the moduleForModel helper.

Let's assume we have a Player model that has level and levelName attributes. We want to call levelUp() to increment the level and assign a new levelName when the player reaches level 5.

You can follow along by generating your own model with ember generate model player.

app/models/player.js

import DS from 'ember-data';

export default DS.Model.extend({
  level:     DS.attr('number', { defaultValue: 0 }),
  levelName: DS.attr('string', { defaultValue: 'Noob' }),

  levelUp() {
    var newLevel = this.incrementProperty('level');
    if (newLevel === 5) {
      this.set('levelName', 'Professional');
    }
  }
});

Now let's create a test which will call levelUp on the player when they are level 4 to assert that the levelName changes. We will use moduleForModel:

tests/unit/models/player-test.js

import { moduleForModel, test } from 'ember-qunit';
import Ember from 'ember';

moduleForModel('player', 'Unit | Model | player', {
  // Specify the other units that are required for this test.
  needs: []
});

test('should increment level when told to', function(assert) {
  // this.subject aliases the createRecord method on the model
  const player = this.subject({ level: 4 });

  // wrap asynchronous call in run loop
  Ember.run(() => player.levelUp());

  assert.equal(player.get('level'), 5, 'level gets incremented');
  assert.equal(player.get('levelName'), 'Professional', 'new level is called professional');
});

Testing Relationships

For relationships you probably only want to test that the relationship declarations are setup properly.

Assume that a User can own a Profile.

You can follow along by generating your own user and profile models with ember generate model user and ember generate model profile.

app/models/profile.js

import DS from 'ember-data';

export default DS.Model.extend({
});

app/models/user.js

import DS from 'ember-data';

export default DS.Model.extend({
  profile: DS.belongsTo('profile')
});

Then you could test that the relationship is wired up correctly with this test.

tests/unit/models/user-test.js

import { moduleForModel, test } from 'ember-qunit';
import Ember from 'ember';

moduleForModel('user', 'Unit | Model | user', {
  // Specify the other units that are required for this test.
  needs: ['model:profile']
});

test('should own a profile', function(assert) {
  const User = this.store().modelFor('user');
  const relationship = Ember.get(User, 'relationshipsByName').get('profile');

  assert.equal(relationship.key, 'profile', 'has relationship with profile');
  assert.equal(relationship.kind, 'belongsTo', 'kind of relationship is belongsTo');
});

Ember Data contains extensive tests around the functionality of relationships, so you probably don't need to duplicate those tests. You could look at the Ember Data tests for examples of deeper relationship testing if you feel the need to do it.

Links:

https://guides.emberjs.com/v2.9.0/testing/testing-models

doc_EmberJs

2016-11-30 16:53:47

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