Testing your Angular application helps you check that your application is working as you expect.
Before writing tests for your Angular application, you should have a basic understanding of the following concepts:
The testing documentation offers tips and techniques for unit and integration testing Angular applications through a sample application created with the Angular CLI. This sample application is much like the one in the Tour of Heroes tutorial.
If you'd like to experiment with the application that this guide describes, run it in your browser or download and run it locally.
The Angular CLI downloads and installs everything you need to test an Angular application with Jasmine testing framework.
The project you create with the CLI is immediately ready to test. Just run the
ng test CLI command:
ng test command builds the application in watch mode, and launches the Karma test runner.
The console output looks the below:
02 11 2022 09:08:28.605:INFO [karma-server]: Karma v6.4.1 server started at http://localhost:9876/ 02 11 2022 09:08:28.607:INFO [launcher]: Launching browsers Chrome with concurrency unlimited 02 11 2022 09:08:28.620:INFO [launcher]: Starting browser Chrome 02 11 2022 09:08:31.312:INFO [Chrome]: Connected on socket -LaEYvD2R7MdcS0-AAAB with id 31534482 Chrome: Executed 3 of 3 SUCCESS (0.193 secs / 0.172 secs) TOTAL: 3 SUCCESS
The last line of the log shows that Karma ran three tests that all passed.
The test output is displayed in the browser using Karma Jasmine HTML Reporter.
Click on a test row to re-run just that test or click on a description to re-run the tests in the selected test group ("test suite").
ng test command is watching for changes.
To see this in action, make a small change to
app.component.ts and save. The tests run again, the browser refreshes, and the new test results appear.
The Angular CLI takes care of Jasmine and Karma configuration for you. It constructs the full configuration in memory, based on options specified in the
If you want to customize Karma, you can create a
karma.conf.js by running the following command:
ng generate config karma
Read more about Karma configuration in the Karma configuration guide.
You can also unit test an Angular application with other testing libraries and test runners. Each library and runner has its own distinctive installation procedures, configuration, and syntax.
src/app folder the Angular CLI generated a test file for the
The test file extension must be
.spec.tsso that tooling can identify it as a file with tests (also known as a spec file).
app.component.spec.ts files are siblings in the same folder. The root file names (
app.component) are the same for both files.
Adopt these two conventions in your own projects for every kind of test file.
It's a good idea to put unit test spec files in the same folder as the application source code files that they test:
Application integration specs can test the interactions of multiple parts spread across folders and modules. They don't really belong to any part in particular, so they don't have a natural home next to any one file.
It's often better to create an appropriate folder for them in the
Of course specs that test the test helpers belong in the
test folder, next to their corresponding helper files.
One of the best ways to keep your project bug-free is through a test suite, but you might forget to run tests all the time.
Continuous integration (CI) servers let you set up your project repository so that your tests run on every commit and pull request.
To test your Angular CLI application in Continuous integration (CI) run the following command:
ng test --no-watch --no-progress
After you've set up your application for testing, you might find the following testing guides useful.
|Code coverage||How much of your app your tests are covering and how to specify required amounts.|
|Testing services||How to test the services your application uses.|
|Basics of testing components||Basics of testing Angular components.|
|Component testing scenarios||Various kinds of component testing scenarios and use cases.|
|Testing attribute directives||How to test your attribute directives.|
|Testing pipes||How to test pipes.|
|Debugging tests||Common testing bugs.|
|Testing utility APIs||Angular testing features.|
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