fix(create): normalize generated src js/jsx extensions for TypeScript

Author: tannerlinsley

.changeset/tidy-seas-hug.md

@@ -0,0 +1,5 @@
+---
+'@tanstack/create': patch
+---
+
+Normalize add-on source filenames under `src/` to TypeScript extensions when TypeScript is enabled, converting `.js` to `.ts` and `.jsx` to `.tsx`.

packages/create/src/template-file.ts

@@ -24,6 +24,28 @@ function convertDotFilesAndPaths(path: string) {
     .join(sep)
 }
 
+function normalizeSourceExtension(target: string, typescript: boolean) {
+  if (!typescript) {
+    return target
+  }
+
+  const normalizedTarget = target.replace(/\\/g, '/')
+
+  if (!normalizedTarget.startsWith('src/')) {
+    return target
+  }
+
+  if (normalizedTarget.endsWith('.js')) {
+    return `${target.slice(0, -3)}.ts`
+  }
+
+  if (normalizedTarget.endsWith('.jsx')) {
+    return `${target.slice(0, -4)}.tsx`
+  }
+
+  return target
+}
+
 export function createTemplateFile(environment: Environment, options: Options) {
   function getPackageManagerAddScript(
     packageName: string,
@@ -146,6 +168,7 @@ export function createTemplateFile(environment: Environment, options: Options) {
     }
 
     let target = convertDotFilesAndPaths(file.replace('.ejs', ''))
+    target = normalizeSourceExtension(target, options.typescript)
 
     // Strip option prefixes from filename (e.g., __postgres__schema.prisma -> schema.prisma)
     const prefixMatch = target.match(/^(.+\/)?__([^_]+)__(.+)$/)

packages/create/tests/template-file.test.ts

@@ -175,4 +175,32 @@ describe('createTemplateFile', () => {
     expect(output.files['/test/foo-dev.txt']).toEqual('pnpm add foo --dev')
     expect(output.files['/test/run-dev.txt']).toEqual('pnpm dev')
   })
+
+  it('should normalize src js files to ts when typescript is enabled', async () => {
+    const { environment, output } = createMemoryEnvironment()
+    const templateFile = createTemplateFile(environment, simpleOptions)
+
+    environment.startRun()
+    await templateFile('src/lib/auth.js', 'export const auth = true')
+    await templateFile('src/lib/auth-client.js', 'export const authClient = true')
+    await templateFile('src/db.js', 'export const db = true')
+    await templateFile('vite.config.js', 'export default {}')
+    environment.finishRun()
+
+    expect(output.files['/test/src/lib/auth.ts']).toBeDefined()
+    expect(output.files['/test/src/lib/auth-client.ts']).toBeDefined()
+    expect(output.files['/test/src/db.ts']).toBeDefined()
+    expect(output.files['/test/vite.config.js']).toBeDefined()
+  })
+
+  it('should normalize src jsx files to tsx when typescript is enabled', async () => {
+    const { environment, output } = createMemoryEnvironment()
+    const templateFile = createTemplateFile(environment, simpleOptions)
+
+    environment.startRun()
+    await templateFile('src/components/auth-button.jsx', 'export default function AuthButton() { return <button>Auth</button> }')
+    environment.finishRun()
+
+    expect(output.files['/test/src/components/auth-button.tsx']).toBeDefined()
+  })
 })