Add basic AST transform test

ember-cli-build.js

@@ -2,11 +2,31 @@
 
 const EmberAddon = require('ember-cli/lib/broccoli/ember-addon');
 
+class Plugin {
+  transform(ast) {
+    this.syntax.traverse(ast, {
+      MustacheStatement(node) {
+        if (node.path.original === 'ast-transform-will-replace') {
+          let value = node.hash.pairs.find(x => x.key === 'with').value.value;
+
+          node.type = 'TextNode';
+          node.chars = value;
+        }
+      }
+    });
+  }
+}
+
 module.exports = function(defaults) {
   let app = new EmberAddon(defaults, {
     // Add options here
   });
 
+  app.registry.add('htmlbars-ast-plugin', {
+    name: 'replace-ast-transform',
+    plugin: Plugin
+  });
+
   /*
     This build file specifies the options for the dummy test app of this
     addon, located in `/tests/dummy`

tests/acceptance/root-test.js

@@ -0,0 +1,14 @@
+import { module, test } from 'qunit';
+import { visit, currentURL } from '@ember/test-helpers';
+import { setupApplicationTest } from 'ember-qunit';
+
+module('Acceptance | root', function(hooks) {
+  setupApplicationTest(hooks);
+
+  test('visiting /', async function(assert) {
+    await visit('/');
+
+    assert.equal(currentURL(), '/');
+    assert.equal(this.element.querySelector('#will-contain-replaced-text').textContent, 'Hello, World');
+  });
+});

tests/dummy/app/templates/application.hbs

@@ -1,3 +1,4 @@
 <h1>ember-cli-htmlbars</h1>
 <a href="/tests">Run Tests</a>
+<div id="will-contain-replaced-text">{{ast-transform-will-replace with="Hello, World"}}</div>
 {{outlet}}