Ensure webpack cache is invalidated for alias change

packages/next/build/webpack-config.ts

@@ -1263,6 +1263,7 @@ export default async function getBaseWebpackConfig(
       target,
       reactProductionProfiling,
       webpack: !!config.webpack,
+      hasRewrites,
     })
 
     const cache: any = {

test/integration/custom-routes/next.config.js

@@ -1,6 +1,7 @@
 module.exports = {
   // target: 'serverless',
   async rewrites() {
+    // no-rewrites comment
     return {
       afterFiles: [
         ...(process.env.ADD_NOOP_REWRITE === 'true'

test/integration/custom-routes/test/index.test.js

@@ -1731,12 +1731,33 @@ describe('Custom routes', () => {
   })
 
   describe('dev mode', () => {
+    let nextConfigContent
+
     beforeAll(async () => {
+      // ensure cache with rewrites disabled doesn't persist
+      // after enabling rewrites
+      await fs.remove(join(appDir, '.next'))
+      nextConfigContent = await fs.readFile(nextConfigPath, 'utf8')
+      await fs.writeFile(
+        nextConfigPath,
+        nextConfigContent.replace('// no-rewrites comment', 'return []')
+      )
+
+      const tempPort = await findPort()
+      const tempApp = await launchApp(appDir, tempPort)
+      await renderViaHTTP(tempPort, '/')
+
+      await killApp(tempApp)
+      await fs.writeFile(nextConfigPath, nextConfigContent)
+
       appPort = await findPort()
       app = await launchApp(appDir, appPort)
       buildId = 'development'
     })
-    afterAll(() => killApp(app))
+    afterAll(async () => {
+      await fs.writeFile(nextConfigPath, nextConfigContent)
+      await killApp(app)
+    })
     runTests(true)
   })