# 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 via `./scripts/build-packages-dist.js`, 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
```

Afterwards the `@angular/cli` and `@angular-devkit/build-angular` should be reverted to the `file:../` urls
and the main `package.json` should be updated with the new versions.

## 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.
