Turbopack: Simplify emitDecoratorMetadata test (#76678)

## What?

Reuse the same code as is checked in page.js, making them consistent and
dropping an additional dependency which also makes it easier to run
while testing.

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Author: timneutkens

test/production/emit-decorator-metadata/app/pages/api/[[...params]].js

@@ -1,14 +1,15 @@
-import { createHandler, Get, Param } from 'next-api-decorators'
+import 'reflect-metadata'
+import { container, singleton } from 'tsyringe'
 
-class HelloHandler {
-  @Get('/:myParam')
-  // This fails due to library looking for Reflect.getMetadata("design:paramtypes", ...).
-  // Design:paramtypes is never emitted due to missing SWC flag.
-  async get(@Param('myParam') myParam) {
-    return {
-      myParam,
-    }
+@singleton()
+class HelloService {
+  getHello() {
+    return 'Hello, world!'
   }
 }
 
-export default createHandler(HelloHandler)
+const helloService = container.resolve(HelloService)
+
+export default function handler(req, res) {
+  res.status(200).json({ message: helloService.getHello() })
+}

test/production/emit-decorator-metadata/index.test.ts

@@ -1,6 +1,6 @@
 import { join } from 'path'
 import webdriver, { BrowserInterface } from 'next-webdriver'
-import { createNext, FileRef } from 'e2e-utils'
+import { createNext } from 'e2e-utils'
 import { NextInstance } from 'e2e-utils'
 import { fetchViaHTTP } from 'next-test-utils'
 
@@ -9,12 +9,8 @@ describe('emitDecoratorMetadata SWC option', () => {
 
   beforeAll(async () => {
     next = await createNext({
-      files: {
-        'jsconfig.json': new FileRef(join(__dirname, 'app/jsconfig.json')),
-        pages: new FileRef(join(__dirname, 'app/pages')),
-      },
+      files: join(__dirname, 'app'),
       dependencies: {
-        'next-api-decorators': '2.0.0',
         'reflect-metadata': '0.1.13',
         'path-to-regexp': '6.2.0',
         tsyringe: '4.6.0',
@@ -41,6 +37,6 @@ describe('emitDecoratorMetadata SWC option', () => {
   it('should compile with emitDecoratorMetadata enabled for API', async () => {
     const res = await fetchViaHTTP(next.url, '/api/something')
     expect(res.status).toBe(200)
-    expect(await res.json()).toEqual({ myParam: 'something' })
+    expect(await res.json()).toEqual({ message: 'Hello, world!' })
   })
 })

test/turbopack-build-tests-manifest.json

@@ -17982,11 +17982,10 @@
     },
     "test/production/emit-decorator-metadata/index.test.ts": {
       "passed": [
-        "emitDecoratorMetadata SWC option should compile with emitDecoratorMetadata enabled"
-      ],
-      "failed": [
+        "emitDecoratorMetadata SWC option should compile with emitDecoratorMetadata enabled",
         "emitDecoratorMetadata SWC option should compile with emitDecoratorMetadata enabled for API"
       ],
+      "failed": [],
       "pending": [],
       "flakey": [],
       "runtimeError": false