Information about the state of a test run needs to be produced in many different formats depending upon how the user wishes to consume the information. In order to faciliate this, Intern publishes specific information about each stage of a test run using a pub/sub mechanism, and registers reporters that listen for these topics and output information in the correct format.

The following reporters are included in a standard Intern installation and can be used by passing the name of the reporter to the reporters array:

If none of the built-in reporters provide the information you need, you can write a custom reporter and reference it using an absolute module ID (i.e. myProject/tests/customReporter). The reporter itself is a single JavaScript object that uses topic names as keys and functions as values:

define([], function () {
	return {
		'/test/start': function (test) {
			console.log(test.id + ' started');
		},
		'/test/end': function (test) {
			console.log(test.id + ' ended');
		}
	};
});

Reporters can also include optional start and stop methods for performing any additional arbitrary work when a reporter is started or stopped:

define([
	'dojo/aspect',
	'intern/lib/Suite'
], function (aspect, Suite) {
	var handles = [];
	return {
		start: function () {
			function augmentJsonValue() {
				/* … */
			}

			handles.push(aspect.after(Suite.prototype, 'toJSON', augmentJsonValue));
		},

		stop: function () {
			var handle;
			while ((handle = handles.pop())) {
				handle.remove();
			}
		}
	}
});