Fix env-config tests for Turbopack (vercel#61503)

## What?

This test was checking internals, specifically the written files. I've
refactored it to only depend on page in the application itself, the
functionality worked fine already in Turbopack.

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Closes NEXT-2325

Author: timneutkens

test/integration/env-config/app/pages/global.js

@@ -1,3 +1,8 @@
+import { useEffect, useState } from 'react'
 export default function Page() {
-  return <p>{process.env.NEXT_PUBLIC_TEST_DEST}</p>
+  const [path, setPath] = useState(null)
+  useEffect(() => {
+    setPath(process.env.NEXT_PUBLIC_TEST_DEST)
+  }, [])
+  return path ? <p id="global-value">{path}</p> : <p>Waiting </p>
 }

test/integration/env-config/test/index.test.js

@@ -86,25 +86,11 @@ const runTests = (mode = 'dev', didReload = false) => {
   })
 
   it('should inline global values during build', async () => {
-    // make sure to build page
-    await renderViaHTTP(appPort, '/global')
+    const browser = await webdriver(appPort, '/global')
 
-    const buildManifest = require(join(
-      __dirname,
-      '../app/.next/build-manifest.json'
-    ))
-
-    const pageFile = buildManifest.pages['/global'].find((filename) =>
-      filename.includes('pages/global')
-    )
-
-    // read client bundle contents since a server side render can
-    // have the value available during render but it not be injected
-    const bundleContent = await fs.readFile(
-      join(appDir, '.next', pageFile),
-      'utf8'
+    expect(await browser.waitForElementByCss('#global-value').text()).toBe(
+      'another'
     )
-    expect(bundleContent).toContain('another')
   })
 
   it('should provide env for SSG', async () => {
@@ -295,7 +281,9 @@ describe('Env Config', () => {
 
         try {
           const browser = await webdriver(appPort, '/global')
-          expect(await browser.elementByCss('p').text()).toBe('another')
+          expect(
+            await browser.waitForElementByCss('#global-value').text()
+          ).toBe('another')
 
           let outputIdx = output.length
 
@@ -313,7 +301,10 @@ describe('Env Config', () => {
           ).toBe(1)
           expect(output.substring(outputIdx)).not.toContain('.env.local')
 
-          await check(() => browser.elementByCss('p').text(), 'replaced')
+          await check(
+            () => browser.waitForElementByCss('#global-value').text(),
+            'replaced'
+          )
 
           outputIdx = output.length
 
@@ -328,7 +319,10 @@ describe('Env Config', () => {
           ).toBe(1)
           expect(output.substring(outputIdx)).toContain('.env.local')
 
-          await check(() => browser.elementByCss('p').text(), 'overridden')
+          await check(
+            () => browser.waitForElementByCss('#global-value').text(),
+            'overridden'
+          )
 
           outputIdx = output.length
 

test/turbopack-tests-manifest.json

@@ -9059,13 +9059,12 @@
       "Env Config test environment should provide env correctly for API routes",
       "Env Config test environment should provide env correctly for SSR",
       "Env Config test environment should provide env for SSG",
-      "Env Config test environment should provide global env to next.config.js"
-    ],
-    "failed": [
+      "Env Config test environment should provide global env to next.config.js",
       "Env Config dev mode should inline global values during build",
       "Env Config dev mode with hot reload should inline global values during build",
       "Env Config test environment should inline global values during build"
     ],
+    "failed": [],
     "pending": [
       "Env Config production mode should have process environment override .env",
       "Env Config production mode should inline global values during build",