puppeteer/tools/mochaRunner/README.md

Mocha Runner

Mocha Runner is a test runner on top of mocha. It uses /test/TestSuites.json and /test/TestExpectations.json files to run mocha tests in multiple configurations and interpret results.

Running tests for Mocha Runner itself.

npm run build && npx c8 node tools/mochaRunner/lib/test.js

Running tests using Mocha Runner

npm run build && npm run test

By default, the runner runs all test suites applicable to the current platform. To pick a test suite, provide the --test-suite arguments. For example,

npm run build && npm run test -- --test-suite chrome-headless

TestSuites.json

Define test suites via the testSuites attribute. parameters can be used in the TestExpectations.json to disable tests based on parameters. The meaning for parameters is defined in parameterDefinitions which tell what env object corresponds to the given parameter.

TestExpectations.json

An expectation looks like this:

  {
    "testIdPattern": "[accessibility.spec]",
    "platforms": ["darwin", "win32", "linux"],
    "parameters": ["firefox"],
    "expectations": ["SKIP"]
  }

testIdPattern defines a string that will be used to prefix-match tests. platforms defines the platforms the expectation is for (or-logic). parameters defines the parameters that the test has to match (and-logic). expectations is the list of test results that are considered to be acceptable.

Currently, expectations are updated manually. The test runner outputs the suggested changes to the expectation file if the test run does not match expectations.