Ember-cli-build code in test environment

Testing
1

I am using a Broccoli funnel in my ember-cli-build.js to include the Ace editor per a recommendation I saw on SO.

    const extraAssets = new Funnel('bower_components/ace-builds/src-min-noconflict', {
        srcDir: '/',
        include: [ '**/*.js' ],
        destDir: '/assets/ace',
    });

    /// ...
    return app.toTree(extraAssets);

But, during testing this doesn’t (seem to) get called. Should ember-cli-build.js be getting called during a test run, and if not, how I might set up the proper funnel so I could properly include the ace editor?

Thanks for your help.