fix: ensure newline separator when appending to files

packages/create/src/environment.ts

@@ -38,6 +38,12 @@ export function createDefaultEnvironment(): Environment {
 
     appendFile: async (path: string, contents: string) => {
       await mkdir(dirname(path), { recursive: true })
+      if (existsSync(path)) {
+        const existing = await readFile(path, 'utf-8')
+        if (existing.length > 0) {
+          await appendFile(path, existing.endsWith('\n') ? '\n' : '\n\n')
+        }
+      }
       return appendFile(path, contents)
     },
     copyFile: async (from: string, to: string) => {
@@ -127,7 +133,13 @@ export function createMemoryEnvironment(returnPathsRelativeTo: string = '') {
 
   environment.appendFile = async (path: string, contents: string) => {
     fs.mkdirSync(dirname(path), { recursive: true })
-    await fs.appendFileSync(path, contents)
+    if (fs.existsSync(path)) {
+      const existing = fs.readFileSync(path, 'utf-8') as string
+      if (existing.length > 0) {
+        fs.appendFileSync(path, existing.endsWith('\n') ? '\n' : '\n\n')
+      }
+    }
+    fs.appendFileSync(path, contents)
   }
   environment.copyFile = async (from: string, to: string) => {
     fs.mkdirSync(dirname(to), { recursive: true })

packages/create/src/frameworks/react/add-ons/mcp/assets/_dot_gitignore.append

@@ -1 +1 @@
-mcp-todos.json
+mcp-todos.json

packages/create/src/frameworks/react/add-ons/sentry/assets/_dot_env.local.append

@@ -8,4 +8,4 @@ VITE_SENTRY_ORG=
 VITE_SENTRY_PROJECT=
 
 # Your Sentry authentication token (from your Sentry account)
-SENTRY_AUTH_TOKEN=
+SENTRY_AUTH_TOKEN=

packages/create/src/frameworks/react/add-ons/strapi/assets/_dot_env.local.append

@@ -1,2 +1,2 @@
 # Strapi configuration
-VITE_STRAPI_URL="http://localhost:1337"
+VITE_STRAPI_URL="http://localhost:1337"

packages/create/src/frameworks/solid/add-ons/strapi/assets/_dot_env.local.append

@@ -1,2 +1,2 @@
 # Strapi configuration
-VITE_STRAPI_URL="http://localhost:1337/api"
+VITE_STRAPI_URL="http://localhost:1337/api"

packages/create/tests/environment.test.ts

@@ -77,7 +77,7 @@ describe('createDefaultEnvironment', () => {
     await environment.copyFile('/test.txt', '/test2.txt')
     environment.finishRun()
 
-    expect(fs.readFileSync('/test.txt', 'utf8')).toEqual('testtest2')
+    expect(fs.readFileSync('/test.txt', 'utf8')).toEqual('test\n\ntest2')
   })
 
   it('should allow deletes', async () => {

packages/create/tests/filename-processing.test.ts

@@ -143,7 +143,7 @@ describe('Filename Processing - Prefix Stripping', () => {
 
     // File should be created with prefix stripped and content appended
     expect(output.files['/test/.env']).toBeDefined()
-    expect(output.files['/test/.env']).toEqual('BASE_VAR=value\n\nDATABASE_URL=postgresql://localhost:5432/mydb\n')
+    expect(output.files['/test/.env']).toEqual('BASE_VAR=value\n\n\nDATABASE_URL=postgresql://localhost:5432/mydb\n')
   })
 
   it('should handle files without prefixes normally', async () => {

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

@@ -51,7 +51,7 @@ describe('createTemplateFile', () => {
     await templateFile('test.txt.append', 'Line 2\n')
     environment.finishRun()
 
-    expect(output.files['/test/test.txt']).toEqual('Line 1\nLine 2\n')
+    expect(output.files['/test/test.txt']).toEqual('Line 1\n\nLine 2\n')
   })
 
   it('should handle enabled add-ons', async () => {