Fix imports for ember 3.5

index.js

@@ -1,19 +1,11 @@
 /* eslint-env node */
 'use strict';
 
-var Append = require('./lib/broccoli-append');
-var path = require('path');
-
 module.exports = {
   name: 'ember-qunit-assert-helpers',
 
-  postprocessTree(type, tree) {
-    this._requireBuildPackages();
-    if (type === 'all' && this.app.tests) {
-      var appendPath = path.join(__dirname, '/vendor/ember-qunit-assert-helpers-loader.js');
-      return new Append(tree, /test-support[A-Za-z0-9-]*/, appendPath);
-    } else {
-      return tree;
-    }
+  included() {
+    this._super.included.apply(this, arguments);
+    this.import('vendor/ember-qunit-assert-helpers-loader.js', { type: 'test' });
   }
 };

vendor/ember-qunit-assert-helpers-loader.js

@@ -1,4 +1,8 @@
 /* globals require */
 
 // Loading the file here will install the asserts onto `QUnit.Assert` class.
-require('ember-qunit-assert-helpers/test-support/install-qunit-asserts');
+// 'ember-qunit-assert-helpers/test-support/install-qunit-asserts' is not available at the current cycle
+// delay the require onto the next tick until all lazy loaded require statements are resolved
+Promise.resolve().then(() => {
+  require('ember-qunit-assert-helpers/test-support/install-qunit-asserts');
+});