puppeteer/utils/testrunner/README.md

TestRunner

This test runner is used internally by Puppeteer to test Puppeteer itself.

• testrunner is a library: tests are node.js scripts
• parallel wrt IO operations
• supports async/await
• modular
• well-isolated state per execution thread
• uses the expect library from npm for assertions.

Installation

npm install --save-dev @pptr/testrunner

Example

Save the following as test.js and run using node:

node test.js

const {TestRunner, Reporter} = require('@pptr/testrunner');
const expect = require('expect')

// 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
});

// Extract jasmine-like DSL into the global namespace
const {describe, xdescribe, fdescribe} = runner;
const {it, fit, xit} = runner;
const {beforeAll, beforeEach, afterAll, afterEach} = runner;

// Test hooks can be async.
beforeAll(async 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.parallelIndex; // 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();