Paul Gschwendtner 7fb3cc07de build: create integration test for ng-update migrations (#32349)
Creates anew integratin test for `ng-update` migrations. The
integration test uses an Angular CLI project that will be updated
using the latest package output symlinked from then `./dist/packages-dist`.

This allows us to ensure that migrations work in real CLI projects.
Another big benefit is that the Angular version is updated to the
latest. This is something we couldn't replicate in unit tests but
is extremely important. It's important because compilation could
break with newer Angular versions (note that migrations are always
executed after the new angular version has been installed).

PR Close #32349
2019-08-29 12:34:43 -07:00
..

Integration tests for Angular

This directory contains end-to-end tests for Angular. Each directory is a self-contained application that exactly mimics how a user might expect Angular to work, so they allow high-fidelity reproductions of real-world issues.

For this to work, we first build the Angular distribution just like we would publish it to npm, then install the distribution into each app.

To test Angular CLI applications, we use the integration test cli-hello-world. When a significant change is released in the CLI, the application should be updated with ng update:

$ cd integration/cli-hello-world
$ yarn install
$ yarn ng update @angular/cli @angular-devkit/build-angular
# yarn build
# yarn test
# typescript version

Render3 tests

The directory cli-hello-world-ivy-compat contains a test for render3 used with the angular cli.

The cli-hello-world-ivy-minimal contains a minimal ivy app that is meant to mimic the bazel equivalent in packages/core/test/bundling/hello_world, and should be kept similar.

Writing an integration test

The API for each test is:

  • Each sub-directory here is an integration test
  • Each test should have a package.json file
  • The test runner will run yarn and yarn test on the package

This means that the test should be started by test script, like

"scripts": {"test": "runProgramA && assertResultIsGood"}

Note that the package.json file uses a special file://../../dist scheme to reference the Angular packages, so that the locally-built Angular is installed into the test app.

Also, beware of floating (non-locked) dependencies. If in doubt you can install the package directly from file:../../node_modules.

Running integration tests

$ ./integration/run_tests.sh

The test runner will first re-build any stale npm packages, then cd into each subdirectory to execute the test.