How does Bootstrap's test suite work?
Bootstrap uses QUnit and Sinon. Each plugin has a file dedicated to its tests in unit/<plugin-name>.js
.
unit/
contains the unit test files for each Bootstrap plugin.vendor/
contains third-party testing-related code (QUnit, jQuery and Sinon).visual/
contains "visual" tests which are run interactively in real browsers and require manual verification by humans.
To run the unit test suite via Karma, run npm run js-test
.
To run the unit test suite via a real web browser, open index.html
in the browser.
How do I add a new unit test?
- Locate and open the file dedicated to the plugin which you need to add tests to (
unit/<plugin-name>.js
). - Review the QUnit API Documentation and use the existing tests as references for how to structure your new tests.
- Write the necessary unit test(s) for the new or revised functionality.
- Run
npm run js-test
to see the results of your newly-added test(s).
Note: Your new unit tests should fail before your changes are applied to the plugin, and should pass after your changes are applied to the plugin.
What should a unit test look like?
- Each test should have a unique name clearly stating what unit is being tested.
- Each test should test only one unit per test, although one test can include several assertions. Create multiple tests for multiple units of functionality.
- Each test should begin with
assert.expect
to ensure that the expected assertions are run. - Each test should follow the project's JavaScript Code Guidelines
Code coverage
Currently we're aiming for at least 80% test coverage for our code. To ensure your changes meet or exceed this limit, run npm run js-compile && npm run js-test
and open the file in js/coverage/lcov-report/index.html
to see the code coverage for each plugin. See more details when you select a plugin and ensure your change is fully covered by unit tests.
Example tests
// Synchronous test
QUnit.test('should describe the unit being tested', function (assert) {
assert.expect(1)
var templateHTML = '<div class="alert alert-danger fade show">' +
'<a class="close" href="#" data-dismiss="alert">×</a>' +
'<p><strong>Template necessary for the test.</p>' +
'</div>'
var $alert = $(templateHTML).appendTo('#qunit-fixture').bootstrapAlert()
$alert.find('.close').trigger('click')
// Make assertion
assert.strictEqual($alert.hasClass('show'), false, 'remove .show class on .close click')
})
// Asynchronous test
QUnit.test('should describe the unit being tested', function (assert) {
assert.expect(2)
var done = assert.async()
var $tooltip = $('<div title="tooltip title"></div>').bootstrapTooltip()
var tooltipInstance = $tooltip.data('bs.tooltip')
var spyShow = sinon.spy(tooltipInstance, 'show')
$tooltip.appendTo('#qunit-fixture')
.on('shown.bs.tooltip', function () {
assert.ok(true, '"shown" event was fired after calling "show"')
assert.ok(spyShow.called, 'show called')
done()
})
.bootstrapTooltip('show')
})