Changing assertions to the preloaded assert/js/assert.js (which should be included in any HTML file that will include JS running our assertions). see https://github.com/phetsims/scenery/issues/300
Changing assertions to the preloaded assert/js/assert.js (which should be included in any HTML file that will include JS running our assertions). see https://github.com/phetsims/scenery/issues/300

phetsims/assert