Make sure that npm run lint doesn't fail on a newly generated app

files/app/config/environment.ts

@@ -3,15 +3,30 @@ import { assert } from '@ember/debug';
 
 const config = loadConfigFromMeta('<%= name %>') as unknown;
 
-assert("config is not an object", typeof config === "object" && config !== null);
-assert("modulePrefix was not detected on your config", "modulePrefix" in config && typeof config.modulePrefix === 'string')
-assert("locationType was not detected on your config", "locationType" in config && typeof config.locationType === 'string')
-assert("rootURL was not detected on your config", "rootURL" in config && typeof config.rootURL === 'string')
-assert("APP was not detected on your config", "APP" in config && typeof config.APP === 'object')
+assert(
+  'config is not an object',
+  typeof config === 'object' && config !== null
+);
+assert(
+  'modulePrefix was not detected on your config',
+  'modulePrefix' in config && typeof config.modulePrefix === 'string'
+);
+assert(
+  'locationType was not detected on your config',
+  'locationType' in config && typeof config.locationType === 'string'
+);
+assert(
+  'rootURL was not detected on your config',
+  'rootURL' in config && typeof config.rootURL === 'string'
+);
+assert(
+  'APP was not detected on your config',
+  'APP' in config && typeof config.APP === 'object'
+);
 
 export default config as {
-  modulePrefix: string,
-  locationType: string,
-  rootURL: string,
-  APP: Record<string, unknown>
+  modulePrefix: string;
+  locationType: string;
+  rootURL: string;
+  APP: Record<string, unknown>;
 } & Record<string, unknown>;

files/app/templates/_js_application.gjs

@@ -2,8 +2,8 @@ import { pageTitle } from 'ember-page-title';
 <% if (welcome) {%>import { WelcomePage } from 'ember-welcome-page';<% } %>
 
 <template>
-  {{pageTitle "<%= namespace %>"}}
-  <% if (welcome) { %>
+  {{pageTitle "<%= namespace %>"}}<% if (welcome) { %>
+
   {{outlet}}
 
   {{! The following component displays Ember's default welcome message. }}

files/app/templates/_ts_application.gts

@@ -2,8 +2,8 @@ import { pageTitle } from 'ember-page-title';
 <% if (welcome) {%>import { WelcomePage } from 'ember-welcome-page';<% } %>
 
 <template>
-  {{pageTitle "<%= namespace %>"}}
-  <% if (welcome) { %>
+  {{pageTitle "<%= namespace %>"}}<% if (welcome) { %>
+
   {{outlet}}
 
   {{! The following component displays Ember's default welcome message. }}

files/tsconfig.json

@@ -1,31 +1,16 @@
 {
   "extends": "@ember/app-tsconfig",
-  "include": [
-    "app", "tests", "types"
-  ],
+  "include": ["app", "tests", "types"],
   "glint": {
-    "environment": [
-      "ember-loose",
-      "ember-template-imports"
-    ]
+    "environment": ["ember-loose", "ember-template-imports"]
   },
   "compilerOptions": {
     "allowJs": true,
     "paths": {
-      "<%= name %>/tests/*": [
-        "./tests/*"
-      ],
-      "<%= name %>/*": [
-        "./app/*"
-      ],
-      "*": [
-        "./types/*"
-      ]
+      "<%= name %>/tests/*": ["./tests/*"],
+      "<%= name %>/*": ["./app/*"],
+      "*": ["./types/*"]
     },
-    "types": [
-      "ember-source/types",
-      "@embroider/core/virtual",
-      "vite/client"
-    ]
-  },
+    "types": ["ember-source/types", "@embroider/core/virtual", "vite/client"]
+  }
 }

tests/default.test.mjs

@@ -52,12 +52,6 @@
         );
       });
 
-      it('successfully lints', async function () {
-        let result = await project.execa('pnpm', ['lint']);
-
-        console.log(result.stdout);
-      });
-
       it('successfully builds', async function () {
         let result = await project.execa('pnpm', ['build']);
 
@@ -137,7 +131,7 @@
 `,
           );
 
           let testResult = await project.execa('pnpm', [
             'testem',
             '--file',
             'testem-dev.js',

tests/helpers.mjs

@@ -19,6 +19,30 @@ export const emberCli = findEmber();
 
 const appName = 'test-app';
 
+export function newProject({ name = appName, flags = [] } = {}) {
+  let dir;
+
+  beforeAll(async () => {
+    const tmpDir = (await tmp.dir()).path;
+    dir = join(tmpDir, name);
+    await execa({
+      cwd: tmpDir,
+    })`${localEmberCli} new ${name} -b ${blueprintPath} --skip-git --pnpm ${flags}`;
+  });
+
+  return {
+    appName: () => name,
+    dir: () => dir,
+    $: (...args) => execa({ cwd: dir })(...args),
+    execa: (program, args, options = {}) => {
+      return execa(program, args, {
+        cwd: dir,
+        ...options,
+      });
+    },
+  };
+}
+
 export function newProjectWithFixtures({
   flags = [],
   fixturePath,

tests/lint.test.mjs

@@ -0,0 +1,27 @@
+import { describe, it, expect } from 'vitest';
+
+import { newProject } from './helpers.mjs';
+
+describe('linting & formatting', function () {
+  describe('JavaScript', function () {
+    let project = newProject();
+
+    it('yields output for JavaScript without errors', async function () {
+      let { exitCode } = await project.execa('pnpm', ['lint']);
+
+      expect(exitCode).to.equal(0);
+    });
+  });
+
+  describe('TypeScript', function () {
+    let project = newProject({
+      flags: ['--typescript'],
+    });
+
+    it('yields output for JavaScript without errors', async function () {
+      let { exitCode } = await project.execa('pnpm', ['lint']);
+
+      expect(exitCode).to.equal(0);
+    });
+  });
+});