# 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 generate integration tests such as `cli-hello-world`.
This was generated with a current version of the CLI, and the only modification was replacement of `@angular/*` packages with their counterparts coming from `file:../../dist/packages-dist/*`.
When a significant change is released in the CLI, the application should be re-generated from scratch:

```bash
$ cd integration
$ rm -rf cli-hello-world
$ ng new cli-hello-world
# Edit cli-hello-world/package.json to point the @angular packages to dist/packages-dist, and preserve local mods to
# ng build
# ng test
# typescript version
```

## Render3 tests

The directory `hello_world_cli` contains a test for render3 used with the angular cli.

If the Angular CLI is modified to generate a render3 application this should be replaced with that project.

If the render3 is updated to support the Angular 5 bootstrap a version of this project should be created that
uses the Angular 5 bootstrap.

## 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

First you must run `build.sh` to create the current distribution.

You can iterate on the tests by keeping the dist folder up-to-date.
See the `package.json` of the test(s) you're debugging, to see which dist/ folders they install from.
Then run the right `tsc --watch` command to keep those dist folders up-to-date, for example:

```
$ ./node_modules/.bin/tsc -p packages/core/tsconfig-build.json --watch
```

Now you can run the integration test, it will re-install from the dist/ folder on each run.

```
$ ./integration/run_tests.sh
```