This patch migrates tests so that they can be run concurrently.
- By default, tests still run in one thread.
- To run tests in 4 parallel threads, run node test/test.js -j 4 or npm run unit -- -j 4
- Environment variable PPTR_PARALLEL_TESTS could be set to override default parallelization
Every test gets passed in a state. State is set up in the beforeAll and beforeEach callbacks,
and should be teared down in the afterAll and afterEach callbacks.
By default, state has a parallelIndex variable initialized that defines the thread index that runs the execution.
This patch:
- introduces Target class that represents any inspectable target, such as service worker or page
- emits events when targets come and go
- introduces target.page() to instantiate a page from a target
Fixes#386, fixes#443.
