# 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 `cli-hello-world-*` integration tests.
When a significant change is released in the CLI, the applications should be updated with
`ng update`:

```bash
$ 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`.

> WARNING
>
> Always ensure that `yarn.lock` files are up-to-date with the corresponding `package.json` files
> (wrt the non-local dependencies - i.e. dependencies whose versions do not start with `file:`).
>
> You can update a `yarn.lock` file by running `yarn install` in the project subdirectory.


## 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.
