servo/tests/wpt/web-platform-tests/encrypted-media/scripts/events.js

function runTest(config,qualifier) {

    var testname = testnamePrefix( qualifier, config.keysystem ) + ', basic events';

    var configuration = getSimpleConfigurationForContent( config.content );

    if ( config.initDataType && config.initData ) configuration.initDataTypes = [ config.initDataType ]

    async_test(function(test)
    {
        var initDataType;
        var initData;
        var mediaKeySession;

        function processMessage(event)
        {
            assert_true(event instanceof window.MediaKeyMessageEvent);
            assert_equals(event.target, mediaKeySession);
            assert_equals(event.type, 'message');
            assert_any( assert_equals,
                        event.messageType,
                        [ 'license-request', 'individualization-request' ] );

            config.messagehandler( event.messageType, event.message ).then( function( response ) {
                waitForEventAndRunStep('keystatuseschange', mediaKeySession, test.step_func(processKeyStatusesChange), test);
                mediaKeySession.update( response ).catch(function(error) {
                    forceTestFailureFromPromise(test, error);
                });
            });
        }

        function processKeyStatusesChange(event)
        {
            assert_true(event instanceof Event);
            assert_equals(event.target, mediaKeySession);
            assert_equals(event.type, 'keystatuseschange');
            test.done();
        }

        navigator.requestMediaKeySystemAccess( config.keysystem, [ configuration ] ).then(function(access) {
            initDataType = access.getConfiguration().initDataTypes[0];

            if ( config.initDataType && config.initData ) {
                initData = config.initData;
            } else {
                initData = getInitData(config.content, initDataType);
            }

            return access.createMediaKeys();
        }).then(test.step_func(function(mediaKeys) {
            mediaKeySession = mediaKeys.createSession();
            waitForEventAndRunStep('message', mediaKeySession, test.step_func(processMessage), test);
            return mediaKeySession.generateRequest(initDataType, initData);
        })).catch(test.step_func(function(error) {
            forceTestFailureFromPromise(test, error);
        }));
    }, testname );

}