puppeteer/utils/testrunner/README.md
Andrey Lushnikov a5db6d412c
test: migrate test.js to support concurrent test execution (#1531)
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.
2017-12-12 13:34:21 -08:00

46 lines
1.2 KiB
Markdown

# TestRunner
- testrunner is a library: no additional binary required; tests are `node.js` scripts
- parallel wrt IO operations
- supports async/await
- modular
- well-isolated state per execution thread
Example
```js
const {TestRunner, Reporter, Matchers} = require('../utils/testrunner');
// Runner holds and runs all the tests
const runner = new TestRunner({
parallel: 2, // run 2 parallel threads
timeout: 1000, // setup timeout of 1 second per test
});
// Simple expect-like matchers
const {expect} = new Matchers();
// Extract jasmine-like DSL into the global namespace
const {describe, xdescribe, fdescribe} = runner;
const {it, fit, xit} = runner;
const {beforeAll, beforeEach, afterAll, afterEach} = runner;
beforeAll(state => {
state.parallelIndex; // either 0 or 1 in this example, depending on the executing thread
state.foo = 'bar'; // set state for every test
});
describe('math', () => {
it('to be sane', async (state, test) => {
state.parallel; // Very first test will always be ran by the 0's thread
state.foo; // this will be 'bar'
expect(2 + 2).toBe(4);
});
});
// Reporter subscribes to TestRunner events and displays information in terminal
const reporter = new Reporter(runner);
// Run all tests.
runner.run();
```