Third party reporters

Mocha allows you to define custom third-party reporters within your own test suite, or by using npm modules. For example if “lcov-reporter” was published to npm, you would simply add it to your package.json in devDependencies and use --reporter lcov-reporter.

Here is a minimalistic sample reporter for Mocha 12, which you can use by executing: mocha --reporter my-reporter.js

import mocha from "mocha";

// You can extend other reporters by changing the class you extend:
// export default class MyReporter extends mocha.reporters.Spec {
export default class MyReporter extends mocha.reporters.Base {
  constructor(runner) {
    super(runner);

    let passes = 0;
    let failures = 0;

    runner.on("pass", function (test) {
      passes++;
      console.log("pass: %s", test.fullTitle());
    });

    runner.on("fail", function (test, err) {
      failures++;
      console.log("fail: %s -- error: %s", test.fullTitle(), err.message);
    });

    runner.on("end", function () {
      console.log("end: %d/%d", passes, passes + failures);
    });
  }
}

For details, look at the implementations in lib/reporters/*.

mocha-examples: third-party-reporter (GitHub) is another sample implementation.

Mocha provides the following events:

start: Execution started
waiting: Execution of root Suite delayed
ready: Execution of root Suite started
end: Execution complete
suite: Test suite execution started
suite end: All tests (and sub-suites) have finished
test: Test execution started
test end: Test completed
hook: Hook execution started
hook end: Hook complete
pass: Test passed
fail: Test failed
pending: Test pending
retry: Test failed and retries