Angular Unit Testing
For this week’s blog post I thought I would take a look at Angular Testing considering in class we have been discussing it and are going to use it for our final project. From the site I found they go into great detail as why it is good to use angular and overall how to conduct it properly. They first start off by listing an example of code that complies properly and “works” but under a more complex situation with dozens of tests in a suite it may begin to fall apart. They go on to explain that for every run it will recompile the components and operations taking up to 75% of your time recompiling and not actually running the tests themselves. Next, they show an Angular Testbed monkey patch that will patch the testing framework resetting the testing module before each run and each test. The TestBed.resetTestingModule function they use will clean up all the overrides, modules, module factories and disposes all active fixtures as well, essentially cleaning up what you have. A _initIfNeeded function then comes into play , preserving the factories from the previous run doing what they need to do. If the flag is false the TestBed function will re-create components required for the test, creating a new zone and testing module but not recompiling anything if moduleFactory is in its correct place. After this they run the code they have, clocking in at a 24 second run time to complete its test suite. Then they apply the patch by calling a setupTestSuite function and replacing beforeEach with beforeAll causing the run time to become 8 seconds. A notice 3x time increase in time efficiency for this certain example. With this patch it allows them to preserve the compliation results and re-use them for multiple test per suite.
After this they start up Karma parallel tests, allowing for the tests to be run in parallel. This website shows all the code which is quite lengthy and I wouldn’t want to subject you all to a blog post that takes up too much space. By clicking the link below you can see all the code they have and more. All and all this website was pretty handy and interesting with what they described and how to show angular to its potential.
https://blog.angularindepth.com/angular-unit-testing-performance-34363b7345ba
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