This patch introduces a tiny test runner to run puppeteer tests.
The test runner is self-container and allows parallel (wrt IO) test execution.
It will also allow us to split tests into multiple files if necessary.
Comparing to the jasmine, the testrunner supports parallel execution, properly
handles "unhandled promise rejection" event and signals.
Comparing to ava/jest, the testrunner doesn't run multiple node processes,
which makes it simpler but sufficient for our goals.
This patch:
- split browser launching logic from Browser into `lib/Launcher.js`
- introduce `puppeteer` namespace which currently has a single `launch`
method to start a browser
With this patch, the browser is no longer created with the `new
Browser(..)` command. Instead, it should be "launched" via the
`puppeteer.launch` method:
```js
const puppeteer = require('puppeteer');
puppeteer.launch().then(async browser => {
...
});
```
With this approach browser instance lifetime matches the lifetime of
actual browser process. This helps us:
- remove proxy streams, e.g. browser.stderr and browser.stdout
- cleanup browser class and make it possible to connect to remote
browser
- introduce events on the browser instance, e.g. 'page' event. In case
of lazy-launching browser, we should've launch browser when an event
listener is added, which is unneded comlpexity.
This patch re-introduces the DEBUG module to expose some of
the puppeteer's internals.
Currently, only the protocol message communication is exposed under
the 'puppeteer:protocol' namespace.
