Catapult has a simple, optionally asynchronous, JavaScript testing framework.
The framework is located in /tracing/base/unittest/
.
Test files exist in <filename>_test.html
files where, typically, filename
will match the name of the file being tested. The tests sit in the same
folder as their respective files.
The general structure of tests is (assuming a file of ui/foo_test.html):
<link rel="import" href="/ui/foo.html">
<script>
'use strict';
tr.b.unittest.testSuite(function() {
test('instantiate', function() {
var myFoo = ui.Foo();
this.addHTMLOutput(myFoo);
});
test('somethingElse', function() {
});
});
Generally, there is one test suite per file (there is an assumption inside the code that this is true).
If you add something to the DOM with appendChild
you should remove it. The
exception is if you use this.addHTMLOutput(element)
. If you use that, then
you should be good, the content will get shown if there is an error,
otherwise it's hidden.
The current tests follow the convention that if the test is there just to draw
things, to name them with a prefix of instantiate. So, instantiate
,
instantiate_multiRow
, etc.
Catapult uses Chai for assertions. We are using Chai's
TDD assert
style.
You'll need to start a dev_server to run the tests
$ bin/run_dev_server
After you start the dev_server, it'll be available at http://localhost:8003.
You'll see links to run unit tests for all projects. We'll use the tracing/
project as an example below.
http://localhost:8003/tracing/tests.html
http://localhost:8003/tracing/tests.html?testSuiteName=ui.foo
http://localhost:8003/tracing/tests.html?testFilterString=blah
If you select the small format
option on the main test page and reload then
the test output will be condensed to a lot smaller, making it easier to see
errors without having to scroll the screen.