diff --git a/apps/tutorial/app/components/selection.gts b/apps/tutorial/app/components/selection.gts
index 351806db4..81c07cd2a 100644
--- a/apps/tutorial/app/components/selection.gts
+++ b/apps/tutorial/app/components/selection.gts
@@ -29,8 +29,10 @@ export class Selection extends Component {
     this.router.transitionTo(event.target.value);
   };
 
-  isSelected = ({ path }: { path: string }) => {
-    return this.docs.currentPath === path;
+  isSelected = (group: { path: string }, tutorial: { path: string }) => {
+    const fullPath = `/${group.path}/${tutorial.path}`;
+
+    return this.docs.currentPath === fullPath;
   };
 
   <template>
@@ -67,7 +69,7 @@ export class Selection extends Component {
 
                     <option
                       value="/{{group.path}}/{{tutorial.path}}"
-                      selected={{this.isSelected tutorial}}
+                      selected={{this.isSelected group tutorial}}
                     >
                       {{titleize tutorial.name}}
                     </option>
diff --git a/apps/tutorial/app/config/environment.d.ts b/apps/tutorial/app/config/environment.d.ts
deleted file mode 100644
index bc1be85ab..000000000
--- a/apps/tutorial/app/config/environment.d.ts
+++ /dev/null
@@ -1,15 +0,0 @@
-export default config;
-
-/**
- * Type declarations for
- *    import config from 'tutorial/config/environment'
- */
-declare const config: {
-  environment: string;
-  modulePrefix: string;
-  podModulePrefix: string;
-  locationType: 'history' | 'hash' | 'none' | 'auto';
-  rootURL: string;
-  APP: Record<string, unknown>;
-  SERVICE_WORKER: boolean;
-};
diff --git a/apps/tutorial/app/config/environment.js b/apps/tutorial/app/config/environment.js
deleted file mode 100644
index 976c12893..000000000
--- a/apps/tutorial/app/config/environment.js
+++ /dev/null
@@ -1,22 +0,0 @@
-import { getGlobalConfig } from '@embroider/macros/src/addon/runtime';
-
-const ENV = {
-  modulePrefix: 'tutorial',
-  environment: import.meta.env.DEV ? 'development' : 'production',
-  rootURL: '/',
-  locationType: 'history',
-  EmberENV: {},
-  APP: {},
-};
-
-export default ENV;
-
-export function enterTestMode() {
-  ENV.locationType = 'none';
-  ENV.APP.rootElement = '#ember-testing';
-  ENV.APP.autoboot = false;
-
-  let config = getGlobalConfig()['@embroider/macros'];
-
-  if (config) config.isTesting = true;
-}
diff --git a/apps/tutorial/app/config/environment.ts b/apps/tutorial/app/config/environment.ts
new file mode 100644
index 000000000..f521ab803
--- /dev/null
+++ b/apps/tutorial/app/config/environment.ts
@@ -0,0 +1,37 @@
+// eslint-disable-next-line @typescript-eslint/ban-ts-comment
+// @ts-expect-error
+import { getGlobalConfig } from '@embroider/macros/src/addon/runtime';
+
+interface Config {
+  isTesting?: boolean;
+  environment: string;
+  modulePrefix: string;
+  podModulePrefix?: string;
+  locationType: 'history' | 'hash' | 'none' | 'auto';
+  rootURL: string;
+  EmberENV?: Record<string, unknown>;
+  APP: Record<string, unknown> & { rootElement?: string; autoboot?: boolean };
+}
+
+const ENV: Config = {
+  modulePrefix: 'tutorial',
+  environment: import.meta.env.DEV ? 'development' : 'production',
+  rootURL: '/',
+  locationType: 'history',
+  EmberENV: {},
+  APP: {},
+};
+
+export default ENV;
+
+export function enterTestMode() {
+  ENV.locationType = 'none';
+  ENV.APP.rootElement = '#ember-testing';
+  ENV.APP.autoboot = false;
+
+  // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
+  const config = getGlobalConfig()['@embroider/macros'];
+
+  // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
+  if (config) config.isTesting = true;
+}
diff --git a/apps/tutorial/tests/helpers/index.js b/apps/tutorial/tests/helpers/index.ts
similarity index 74%
rename from apps/tutorial/tests/helpers/index.js
rename to apps/tutorial/tests/helpers/index.ts
index 7f70de80f..e190f567e 100644
--- a/apps/tutorial/tests/helpers/index.js
+++ b/apps/tutorial/tests/helpers/index.ts
@@ -2,13 +2,14 @@ import {
   setupApplicationTest as upstreamSetupApplicationTest,
   setupRenderingTest as upstreamSetupRenderingTest,
   setupTest as upstreamSetupTest,
+  type SetupTestOptions,
 } from 'ember-qunit';
 
-// This file exists to provide wrappers around ember-qunit's / ember-mocha's
+// This file exists to provide wrappers around ember-qunit's
 // test setup functions. This way, you can easily extend the setup that is
 // needed per test type.
 
-function setupApplicationTest(hooks, options) {
+function setupApplicationTest(hooks: NestedHooks, options?: SetupTestOptions) {
   upstreamSetupApplicationTest(hooks, options);
 
   // Additional setup for application tests can be done here.
@@ -23,17 +24,17 @@ function setupApplicationTest(hooks, options) {
   // This is also a good place to call test setup functions coming
   // from other addons:
   //
-  // setupIntl(hooks); // ember-intl
+  // setupIntl(hooks, 'en-us'); // ember-intl
   // setupMirage(hooks); // ember-cli-mirage
 }
 
-function setupRenderingTest(hooks, options) {
+function setupRenderingTest(hooks: NestedHooks, options?: SetupTestOptions) {
   upstreamSetupRenderingTest(hooks, options);
 
   // Additional setup for rendering tests can be done here.
 }
 
-function setupTest(hooks, options) {
+function setupTest(hooks: NestedHooks, options?: SetupTestOptions) {
   upstreamSetupTest(hooks, options);
 
   // Additional setup for unit tests can be done here.
diff --git a/apps/tutorial/tests/helpers/mocks.ts b/apps/tutorial/tests/helpers/mocks.ts
new file mode 100644
index 000000000..9a91c58f2
--- /dev/null
+++ b/apps/tutorial/tests/helpers/mocks.ts
@@ -0,0 +1,94 @@
+import Service from '@ember/service';
+
+/**
+ * Build the structure used by the docs service for mocking.
+ */
+function makeDocsTree(treeData: [string, string[]][]) {
+  const pages = [];
+
+  for (const [groupName, tutorialNames] of treeData) {
+    const groupPath = groupName
+      .toLowerCase()
+      .replace(/ /g, '-')
+      .replace(/[^a-z0-9-]/g, '');
+
+    const groupPages = [];
+
+    for (const tutorialName of tutorialNames) {
+      const tutorialPath = tutorialName
+        .toLowerCase()
+        .replace(/ /g, '-')
+        .replace(/[^a-z0-9-]/g, '');
+
+      const prosePath = `/${groupPath}/${tutorialPath}/prose.md`;
+
+      const page = {
+        path: tutorialPath,
+        name: tutorialName,
+        cleanedName: tutorialName.replace(/-/g, ' '),
+        pages: [
+          {
+            path: prosePath,
+            name: 'prose',
+            groupName: tutorialName.replace(/-/g, ' '),
+            cleanedName: 'prose',
+          },
+        ],
+        first: prosePath,
+      };
+
+      groupPages.push(page);
+    }
+
+    const group = {
+      path: groupPath,
+      name: groupName,
+      cleanedName: groupName.replace(/-/g, ' '),
+      pages: groupPages,
+      first: `/${groupPath}/${groupPages[0]?.path}/prose.md`,
+    };
+
+    pages.push(group);
+  }
+
+  return {
+    name: 'root',
+    pages,
+    path: 'root',
+    first: `/${pages[0]?.path}/${pages[0]?.pages[0]?.path}/prose.md`,
+  };
+}
+
+export class MockDocsService extends Service {
+  #groupsTree = {};
+  #currentPath = '/';
+
+  get grouped() {
+    return this.#groupsTree;
+  }
+
+  get currentPath() {
+    return this.#currentPath;
+  }
+
+  // Test extension
+  _setGroupsData(treeData: [string, string[]][]) {
+    this.#groupsTree = makeDocsTree(treeData);
+  }
+
+  _setCurrentPath(path: string) {
+    this.#currentPath = path;
+  }
+}
+
+export class MockRouterService extends Service {
+  transitionTo(newRoute: string) {
+    this._assert.step(`transition to: ${newRoute}`);
+  }
+
+  // Test extension
+  _assert!: Assert;
+  _setAssert(assert: Assert) {
+    this._assert = assert;
+  }
+}
diff --git a/apps/tutorial/tests/integration/components/selection-test.gts b/apps/tutorial/tests/integration/components/selection-test.gts
new file mode 100644
index 000000000..b55756f88
--- /dev/null
+++ b/apps/tutorial/tests/integration/components/selection-test.gts
@@ -0,0 +1,81 @@
+import { render, select } from '@ember/test-helpers';
+import { module, test } from 'qunit';
+
+import { Selection } from 'tutorial/components/selection';
+import { setupRenderingTest } from 'tutorial/tests/helpers';
+
+import { MockDocsService, MockRouterService } from '../../helpers/mocks';
+
+module('Integration | Component | selection', function (hooks) {
+  setupRenderingTest(hooks);
+
+  hooks.beforeEach(function () {
+    this.owner.register('service:docs', MockDocsService);
+    this.owner.register('service:router', MockRouterService);
+  });
+
+  test('it renders groups and options', async function (assert) {
+    const docsSvc = this.owner.lookup('service:docs') as unknown as MockDocsService;
+
+    docsSvc._setGroupsData([
+      [
+        '1-introduction',
+        ['1-basics', '2-adding-data', '3-transforming-data', '4-multiple-transforms'],
+      ],
+      ['2-reactivity', ['1-values', '2-decorated-values', '3-derived-values']],
+      ['3-event-handling', ['1-dom-events']],
+    ]);
+
+    await render(<template><Selection /></template>);
+    assert.dom('select').hasAttribute('name', 'tutorial');
+    assert.dom('select > optgroup').exists({ count: 3 });
+    assert.dom('option').exists({ count: 8 });
+    // Check group labels
+    assert.dom('optgroup:nth-child(1)').hasAttribute('label', 'Introduction');
+    assert.dom('optgroup:nth-child(2)').hasAttribute('label', 'Reactivity');
+    assert.dom('optgroup:nth-child(3)').hasAttribute('label', 'Event Handling');
+    // Spot check some option values
+    assert
+      .dom('optgroup:nth-child(1) option:nth-child(4)')
+      .hasValue('/1-introduction/4-multiple-transforms');
+    assert.dom('optgroup:nth-child(1) option:nth-child(4)').hasText('Multiple Transforms');
+    assert
+      .dom('optgroup:nth-child(2) option:nth-child(2)')
+      .hasValue('/2-reactivity/2-decorated-values');
+    assert.dom('optgroup:nth-child(2) option:nth-child(2)').hasText('Decorated Values');
+  });
+
+  test('it handles selection', async function (assert) {
+    const routerSvc = this.owner.lookup('service:router') as unknown as MockRouterService;
+
+    routerSvc._setAssert(assert);
+
+    const docsSvc = this.owner.lookup('service:docs') as unknown as MockDocsService;
+
+    docsSvc._setGroupsData([
+      ['english', ['one', 'two', 'three']],
+      ['spanish', ['uno', 'dos', 'tres']],
+      ['german', ['eins', 'zwei', 'drei']],
+    ]);
+    docsSvc._setCurrentPath('/spanish/dos');
+
+    await render(<template><Selection /></template>);
+    assert.dom('select').hasAttribute('name', 'tutorial');
+    assert.dom('select > optgroup').exists({ count: 3 });
+    assert.dom('option').exists({ count: 9 });
+
+    assert.dom('select').hasValue('/spanish/dos');
+    // Not sure why, but `:checked` is how you get selected option
+    assert.dom('option:checked').hasValue('/spanish/dos').hasText('Dos');
+
+    await select('select', '/german/eins');
+    docsSvc._setCurrentPath('/german/eins');
+    assert.dom('option:checked').hasValue('/german/eins').hasText('Eins');
+
+    await select('select', '/english/three');
+    docsSvc._setCurrentPath('/english/three');
+    assert.dom('option:checked').hasValue('/english/three').hasText('Three');
+
+    assert.verifySteps(['transition to: /german/eins', 'transition to: /english/three']);
+  });
+});
diff --git a/apps/tutorial/tests/test-helper.js b/apps/tutorial/tests/test-helper.ts
similarity index 100%
rename from apps/tutorial/tests/test-helper.js
rename to apps/tutorial/tests/test-helper.ts
diff --git a/apps/tutorial/tsconfig.json b/apps/tutorial/tsconfig.json
index 93714cbb8..40c11b41d 100644
--- a/apps/tutorial/tsconfig.json
+++ b/apps/tutorial/tsconfig.json
@@ -14,7 +14,7 @@
       "tutorial/*": ["./app/*"],
       "*": ["./types/*"]
     },
-    "types": ["ember-source/types", "@embroider/core/virtual"]
+    "types": ["vite/client", "ember-source/types", "@embroider/core/virtual"]
   },
   "include": ["app/**/*", "tests/**/*", "types/**/*"]
 }