Ember.js Testing Guide

These guidelines are specific to the 1.13.x version of Ember.js

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119

Unit Tests: Testing default property values
Unit Tests: Testing expected mixins are present
Unit Tests: Testing dependent keys are correct
Unit Tests: Testing observer keys are correct
Component Integration Tests: Testing default rendered state
Element vs jQuery object
Component Integration Tests: find() and hasClass()
Rendering templates
Asynchronous testing

Comments

Test case descriptions SHOULD be descriptive enough to void the need for DocBlocks
Test cases MAY be preceded with JSDoc DocBlocks but it is RECOMMENDED they do not. Traditional DocBlocks with tags do not add any value, though a DocBlock containing comments explaining something peculiar about the test case MAY be employed. Do so sparingly.
Comments MAY be used within test cases but there should rarely be logic complicated enough that comments are warranted. These are tests - there should only be light-weight logic most likely testing input and output or isolated behaviors.

Naming: Unit Tests

Test cases asserting that default properties are assigned to their expected values MUST be named: Default property values are set correctly
- See Example
Test cases asserting that expected Mixins are mixed in MUST be named: Expected Mixins are present
- See Example
Test cases asserting that computed properties are observing the correct properties MUST be named: Dependent keys are correct
- See Example
Test cases asserting that observer properties are observing the correct properties MUST be named: Observer keys are correct
- See Example

Naming: Component Unit Tests

Test cases asserting that there is no DOM-reference leakage outside of a component MUST be named: There are no references to Ember.$, $ or jQuery

Naming: Component Integration Tests

Test cases asserting the default rendered state of the component MUST be named: Default rendered state
- See Example

assert.expect()

MUST only be used in asynchronous tests
When used it MUST be the first line of code in the test case

See example

Specificity

Assertions MUST be the most specific possible
- in the case of ember-cli-qunit this means that assert.strictEqual() is preferred over assert.equal(), for example

Element vs jQuery object

If a const or let assignment directly references a DOM element then the name used MUST end with the string "Element"
If a const or let assignment references a jQuery reference to a DOM element then the name used MUST not end with the string "Element"

See Example

Component Unit Tests

MUST test:
- default values of all properties, including Enums, except for: See Example
  - attributeBindings
  - classNames
  - classNameBindings
- that any expected mixins are mixed in See Example
- the dependent keys computed properties are observing, via the _dependentKeys property See Example
- the observer keys ember observers are observing, via the __ember_observes__ property See Example
- the logic of the computed property functions
- the logic of any actions
- the logic of any event handlers
- that there is no DOM-reference leakage outside of a component
  - This is done in Unit Tests due to the limitation that we cannot invoke specific events or directly call specific functions/methods on the component from within Integration tests
Whenever testing default values of properties in components, mixins, routes, etc, you SHOULD assert the properties in the same alphabetical order as they appear in the unit under test. This makes it easier to find the related assertion, confirm one hasn't been missed, etc.

Of course there are always exceptions...

if an action or method only accesses or affects the DOM then it does not need to be Unit tested and Integration test only coverage is preferred
an action or method, in addition to accessing or affecting the DOM, which also interacts with properties on the component, may need to also be Unit tested
- if the properties being set only pertain to the rendering of DOM, and not used by another other logic flow of the component, then Integration test only coverage is preferred
- if the properties being set pertain to the rendering of the DOM and are also used by other logic flow the action or method should also be Unit tested
  - it is recommended that the logic of the action or method be broken into separate method (calls) to encompass more discreet units of work. Doing so will then make it very easy to either Unit or Integration test an action or method without having to exercise it via both, having to contrive data paths to get to the parts desired to be tested.

Component Integration Tests

MUST test:
- default rendered state of the component (only populating required properties), including: See Example
  - default classes applied
  - default properties/attributes (values) applied
  - default characteristics of any mixins used by the component
- any properties that can be provided as different values that cause a DOM change
- any bound values
  - do not need to exercise the entire range of possible logic - this is done in the unit test. Instead, this testing ensures that the template has bound things together correctly
- actions
  - do not need to test the logic of the action - this is done in the unit test. Instead, this testing ensures that the template has bound things together correctly
MUST reference a component under test via this.$( '>:first-child' ) rather than via a class name when appropriate, which is the majority of the time.
- Not using a classname removes the too-tight coupling between the styling used and the functionality provided by the component.
- When this is not always appropriate is when you are rendering multiple components and need to access ones beyond first-child.
MUST use find() for all internal selectors See Example
MUST use hasClass() to assert class existence for all DOM elements that are not nested inside of the component AND are only differentiated by their class See Example
SHOULD use find().length to assert.ok() the existence of a class when the above is not possible See Example

Rendering Templates

Template strings MUST be tagged/prefixed with hbs instead of compiled with Ember.HTMLBars.compile
If a template needs to be registered on the registry it MUST also be unregistered at the conclusion of its use

See Example

Example: Testing default property values

// sl-ember-components/components/sl-alert

import Ember from 'ember';
import layout from '../templates/components/sl-alert';

/**
 * Bootstrap theme names for alert components
 *
 * @memberof module:addon/components/sl-alert
 * @enum {String}
 * @property {String} DANGER 'danger'
 * @property {String} INFO 'info'
 * @property {String} SUCCESS 'success'
 * @property {String} WARNING 'warning'
 */
export const Theme = Object.freeze({
    DANGER: 'danger',
    INFO: 'info',
    SUCCESS: 'success',
    WARNING: 'warning'
});

/**
 * @module
 * @augments ember/Component
 */
export default Ember.Component.extend({

    // -------------------------------------------------------------------------
    // Dependencies

    // -------------------------------------------------------------------------
    // Attributes

    /** @type {String} */
    ariaRole: 'alert',

    /** @type {String[]} */
    classNameBindings: [
        'themeClassName',
        'dismissable:alert-dismissable'
    ],

    /** @type {String[]} */
    classNames: [
        'alert',
        'sl-alert'
    ],

    /** @type {Object} */
    layout,

    // -------------------------------------------------------------------------
    // Actions

    /**
     * @type {Object}
     */
    actions: {

        /**
         * Trigger a bound "dismiss" action when the alert is dismissed
         *
         * @function actions:dismiss
         * @returns {undefined}
         */
        dismiss() {
            this.sendAction( 'dismiss' );
        }

    },

    // -------------------------------------------------------------------------
    // Events

    // -------------------------------------------------------------------------
    // Properties

    /**
     * Whether to make the alert dismissable or not
     *
     * @type {Boolean}
     */
    dismissable: false,

    /**
     * The Bootstrap "theme" style to apply to the alert
     *
     * @type {Theme}
     */
    theme: Theme.INFO,

    // -------------------------------------------------------------------------
    // Observers

    // -------------------------------------------------------------------------
    // Methods

    /**
     * The generated Bootstrap "theme" style class for the alert
     *
     * @function
     * @returns {String} Defaults to "alert-info"
     */
    themeClassName: Ember.computed(
        'theme',
        function() {
            const theme = this.get( 'theme' );

            return `alert-${theme}`;
        }
    )

});

// component integration test

import { Theme } from 'sl-ember-components/components/sl-alert';

test( 'Default property values are set correctly', function( assert ) {
    const component = this.subject();

    assert.strictEqual(
        component.get( 'ariaRole' ),
        'alert',
        'ariaRole: "alert"'
    );

    assert.strictEqual(
        component.get( 'dismissable' ),
        false,
        'dismissable: false'
    );

    assert.strictEqual(
        component.get( 'theme' ),
        Theme.INFO,
        `theme: "${Theme.INFO}"`
    );
});

Example: Testing expected mixins are present

// unit test

import InputBasedMixin from 'your-library/mixins/input-based';

test( 'Expected Mixins are present', function( assert ) {
    assert.ok(
        InputBasedMixin.detect( this.subject() ),
        'The input-based mixin is present'
    );
});

Example: Testing dependent keys are correct

// unit test

test( 'Dependent keys are correct', function( assert ) {
    const component = this.subject();

    const currentLabelDependentKeys = [
        'label',
        'pending',
        'pendingLabel'
    ];

    const sizeClassDependentKeys = [
        'size'
    ];

    assert.deepEqual(
        component.currentLabel._dependentKeys,
        currentLabelDependentKeys,
        'Dependent keys are correct for currentLabel()'
    );

    assert.deepEqual(
        component.sizeClass._dependentKeys,
        sizeClassDependentKeys,
        'Dependent keys are correct for sizeClass()'
    );
});

Example: Testing observer keys are correct

// unit test

test( 'Observer keys are correct', function( assert ) {
    const component = this.subject();

    const setupTypeaheadKeys = [
        'suggestions'
    ];

    assert.deepEqual(
        component.setupTypeahead.__ember_observes__,
        setupTypeaheadKeys,
        'Observer keys are correct for setupTypeahead()'
    );
});

Example: Testing default rendered-state

// sl-ember-components/components/sl-alert

import Ember from 'ember';
import layout from '../templates/components/sl-alert';

/**
 * Bootstrap theme names for alert components
 *
 * @memberof module:addon/components/sl-alert
 * @enum {String}
 * @property {String} DANGER 'danger'
 * @property {String} INFO 'info'
 * @property {String} SUCCESS 'success'
 * @property {String} WARNING 'warning'
 */
export const Theme = Object.freeze({
    DANGER: 'danger',
    INFO: 'info',
    SUCCESS: 'success',
    WARNING: 'warning'
});

/**
 * @module
 * @augments ember/Component
 */
export default Ember.Component.extend({

    // -------------------------------------------------------------------------
    // Dependencies

    // -------------------------------------------------------------------------
    // Attributes

    /** @type {String} */
    ariaRole: 'alert',

    /** @type {String[]} */
    classNameBindings: [
        'themeClassName',
        'dismissable:alert-dismissable'
    ],

    /** @type {String[]} */
    classNames: [
        'alert',
        'sl-alert'
    ],

    /** @type {Object} */
    layout,

    // -------------------------------------------------------------------------
    // Actions

    /**
     * @type {Object}
     */
    actions: {

        /**
         * Trigger a bound "dismiss" action when the alert is dismissed
         *
         * @function actions:dismiss
         * @returns {undefined}
         */
        dismiss() {
            this.sendAction( 'dismiss' );
        }

    },

    // -------------------------------------------------------------------------
    // Events

    // -------------------------------------------------------------------------
    // Properties

    /**
     * Whether to make the alert dismissable or not
     *
     * @type {Boolean}
     */
    dismissable: false,

    /**
     * The Bootstrap "theme" style to apply to the alert
     *
     * @type {Theme}
     */
    theme: Theme.INFO,

    // -------------------------------------------------------------------------
    // Observers

    // -------------------------------------------------------------------------
    // Methods

    /**
     * The generated Bootstrap "theme" style class for the alert
     *
     * @function
     * @returns {String} Defaults to "alert-info"
     */
    themeClassName: Ember.computed(
        'theme',
        function() {
            const theme = this.get( 'theme' );

            return `alert-${theme}`;
        }
    )

});

// ../templates/components/sl-alert

{{#if dismissable}}
    <button
        {{action "dismiss"}}
        class="close"
        data-dismiss="alert"
        type="button"
    >
        <span aria-hidden="true">&times;</span>
        <span class="sr-only">Close</span>
    </button>
{{/if}}

{{yield}}

// component integration test

test( 'Default rendered state', function( assert ) {

    this.render( hbs`
        {{#sl-alert}}
            Default info alert
        {{/sl-alert}}
    ` );

    assert.ok(
        this.$( '>:first-child' ).hasClass( 'alert' ),
        'Has class "alert"'
    );

    assert.ok(
        this.$( '>:first-child' ).hasClass( 'alert-info' ),
        'Default theme class is applied'
    );

    assert.strictEqual(
        this.$( '>:first-child' ).attr( 'role' ),
        'alert',
        'ARIA role is applied'
    );
});

Example: Element vs jQuery object

// unit or integration test

test( 'example', function( assert ) {
    const input = this.$( '>:first-child' ).find( 'input' );
    const inputElement = input.get( 0 );
});

Example: Component integration tests - find() and hasClass()

// component

export default Ember.Component.extend({

    // -------------------------------------------------------------------------
    // Attributes

    /** @type {String[]} */
     classNames: [
        'componentClass'
    ]
});

// template

<p class="help-block">{{helpText}}</p>

<span>Some content</span>

<span class="moreText">Some more</span>

// component integration test

assert.ok(
    this.$( '>:first-child' ).hasClass( 'componentClass' ),
    'Has expected class'
);

assert.ok(
    this.$( '>:first-child' ).find( '> p' ).hasClass( '.help-block' )
    'Has expected class'
);

assert.ok(
    this.$( '>:first-child' ).find( 'span.moreText' ).length
    'Has more text'
);

Example: Rendering templates

// unit or integration test

import hbs from 'htmlbars-inline-precompile';

test( 'Testing something needing template', function( assert ) {
    const template = hbs`
        {{#some-component label="One" name="one"}}
            One
        {{/some-component}}
    `;

    this.registry.register( 'template:test-template',  template );

    ...

    this.registry.unregister( 'template:test-template' );
});

Example: Asynchronous testing

// unit or integration test

test( 'Testing asynchronous behavior', function( assert ) {
    assert.expect( 2 );

    const done = assert.async();

    this.$( '.someSelector' ).queue( () => {
        assert.strictEqual(
            ...
        );

        assert.ok(
            ...
        );

        done();
    });
});

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ember-testing.md

ember-testing.md

Ember.js Testing Guide

Table of Contents

Test Cases

Assertions

DOM References

Components

Rendering Templates

Examples

Comments

Naming: Unit Tests

Naming: Component Unit Tests

Naming: Component Integration Tests

assert.expect()

Specificity

Element vs jQuery object

Component Unit Tests

Component Integration Tests

Rendering Templates

Example: Testing default property values

Example: Testing expected mixins are present

Example: Testing dependent keys are correct

Example: Testing observer keys are correct

Example: Testing default rendered-state

Example: Element vs jQuery object

Example: Component integration tests - find() and hasClass()

Example: Rendering templates

Example: Asynchronous testing

Files

ember-testing.md

Latest commit

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ember-testing.md

File metadata and controls

Ember.js Testing Guide

Table of Contents

Test Cases

Assertions

DOM References

Components

Rendering Templates

Examples

Comments

Naming: Unit Tests

Naming: Component Unit Tests

Naming: Component Integration Tests

assert.expect()

Specificity

Element vs jQuery object

Component Unit Tests

Component Integration Tests

Rendering Templates

Example: Testing default property values

Example: Testing expected mixins are present

Example: Testing dependent keys are correct

Example: Testing observer keys are correct

Example: Testing default rendered-state

Example: Element vs jQuery object

Example: Component integration tests - find() and hasClass()

Example: Rendering templates

Example: Asynchronous testing