Selectively Run Mocha Tests In Browser - unit-testing

Question

I want to selectively run mocha tests in the browser even after multiple files with tests have been loaded with requirejs. At the moment if I load user_model_tests and user_view_tests with require js, every time after that when I call mocha.run() all of them are run.
The end goal is to run tests selectively based on the user checking off boxes on a form, and having only those tests appear in the browser. Right now, this works the first time to selectively load and run tests, but once tests are loaded, even if the user unchecks the boxes, the tests are still run because they were required in previously.
Is there a solution within the mocha framework to this? Or do I have to somehow dump requirejs's cache?
var TestRunner = {
start: function(tests) {
require(tests, function(require) { mocha.run() });
},
formListener: function() {
$('form.test-selector').submit(function(event) {
event.preventDefault();
var choices = $('form.test-selector input.test-choice');
var selections = []
_.forEach(choices, function(choice) {
if ($(choice).is(':checked')) {
selections.push($(choice).val());
}
})
TestRunner.start(selections);
})
}
};
$(document).ready(function() {
TestRunner.formListener();
})

Answer 1

When using both requirejs and mocha:
Mocha will run whatever tests have been loaded by requirejs in the context.
The trick is to use require.undef() to get remove the tests from the context each time after the tests are run. Once this has been done, you'll have a clean slate to run whichever tests you want the next time.
start: function(tests) {
$('#mocha').html('');
require(tests.concat('vendor/mocha'), function() {
var mocha = _(arguments).last();
mocha.setup('bdd');
var expect = chai.expect
chai.use(chaijquery);
mocha.run();
});
require.undef('vendor/mocha')
tests.forEach(function(test) {
require.undef(test);
})
},
(Notice the last 4 lines which remove the test files from the context.)