Example QUnit Test using StealJS for Dependency Injection

unit-test-dependency-injection-using-stealjs.js

import QUnit from 'steal-qunit';

QUnit.module('Tournament Details ViewModel', {
    beforeEach: function () {
        localStorage.clear();
    }
});

test('should load a tournament', (assert) => {
    let done = assert.async(),
        localSteal,
        localTournament,
        vm;

    // clone a local copy of steal
    localSteal = steal.clone();

    // use `steal.System` to create the module to be injected for use in test
    localTournament = localSteal.System.newModule({
        __useDefault: true,
        default: {
            get: () => Promise.resolve(new can.Map({ name: 'Test Name' }))
        }
    });

    // set up local steal and call `startup()` to read configuration file
    localSteal.System.configMain = steal.System.configMain;
    localSteal.System.baseURL = steal.System.baseURL;
    localSteal.startup({ main: '@empty' }).then(function () {
        
        // set fully normalized module name to inject the test module
        localSteal.System.set("[email protected]#models/tournament/tournament", localTournament);

        // re-import the module-under-test so that it will use the injected dependency
        localSteal.System.import('components/tournament/details/viewModel').then(function (ViewModel) {

            // run QUnit test using module returned by `System.import`
            vm = new ViewModel({
                tournamentId: 2
            });

            vm.bind('tournament', function (ev, newVal) {
                assert.equal(newVal.attr('name'), 'Test Name', 'with the correct name' );
                done();
            });
        });
    });
})

Cool, what would be the ideal API for doing this kind of thing?

Sorry, I didn't see your question @matthewp. I'm not sure exactly what a good API would be for this. An issue has been created for this: stealjs/steal#509 so maybe we can get the discussion going there.