Do not polyfill node built-in modules on edge functions

packages/next/build/index.ts

@@ -723,7 +723,7 @@ export default async function build(
       if (result.errors.length > 5) {
         result.errors.length = 5
       }
-      const error = result.errors.join('\n\n')
+      let error = result.errors.join('\n\n')
 
       console.error(chalk.red('Failed to compile.\n'))
 
@@ -739,6 +739,13 @@ export default async function build(
         )
       }
 
+      const breakingChangeIndex = error.indexOf(
+        '\n\nBREAKING CHANGE: webpack < 5 used to include polyfills for node.js core modules by default.'
+      )
+      if (breakingChangeIndex >= 0) {
+        error = error.slice(0, breakingChangeIndex)
+      }
+
       console.error(error)
       console.error()
 

packages/next/build/webpack-config.ts

@@ -626,40 +626,10 @@ export default async function getBaseWebpackConfig(
 
       setimmediate: 'next/dist/compiled/setimmediate',
     },
-    ...(targetWeb
+    ...(isEdgeRuntime
       ? {
-          // Full list of old polyfills is accessible here:
-          // https://github.com/webpack/webpack/blob/2a0536cf510768111a3a6dceeb14cb79b9f59273/lib/ModuleNotFoundError.js#L13-L42
           fallback: {
-            assert: require.resolve('next/dist/compiled/assert'),
-            buffer: require.resolve('next/dist/compiled/buffer/'),
-            constants: require.resolve(
-              'next/dist/compiled/constants-browserify'
-            ),
-            crypto: require.resolve('next/dist/compiled/crypto-browserify'),
-            domain: require.resolve('next/dist/compiled/domain-browser'),
-            http: require.resolve('next/dist/compiled/stream-http'),
-            https: require.resolve('next/dist/compiled/https-browserify'),
-            os: require.resolve('next/dist/compiled/os-browserify'),
-            path: require.resolve('next/dist/compiled/path-browserify'),
-            punycode: require.resolve('next/dist/compiled/punycode'),
             process: require.resolve('./polyfills/process'),
-            // Handled in separate alias
-            querystring: require.resolve('next/dist/compiled/querystring-es3'),
-            stream: require.resolve('next/dist/compiled/stream-browserify'),
-            string_decoder: require.resolve(
-              'next/dist/compiled/string_decoder'
-            ),
-            sys: require.resolve('next/dist/compiled/util/'),
-            timers: require.resolve('next/dist/compiled/timers-browserify'),
-            tty: require.resolve('next/dist/compiled/tty-browserify'),
-            // Handled in separate alias
-            // url: require.resolve('url/'),
-            util: require.resolve('next/dist/compiled/util/'),
-            vm: require.resolve('next/dist/compiled/vm-browserify'),
-            zlib: require.resolve('next/dist/compiled/browserify-zlib'),
-            events: require.resolve('next/dist/compiled/events/'),
-            setImmediate: require.resolve('next/dist/compiled/setimmediate'),
           },
         }
       : undefined),
@@ -1280,6 +1250,81 @@ export default async function getBaseWebpackConfig(
               },
             ]
           : []),
+        ...(!isServer && !isEdgeRuntime
+          ? [
+              {
+                oneOf: [
+                  {
+                    issuerLayer: 'middleware',
+                    resolve: {
+                      fallback: {
+                        process: require.resolve('./polyfills/process'),
+                      },
+                    },
+                  },
+                  {
+                    resolve: {
+                      // Full list of old polyfills is accessible here:
+                      // https://github.com/webpack/webpack/blob/2a0536cf510768111a3a6dceeb14cb79b9f59273/lib/ModuleNotFoundError.js#L13-L42
+                      fallback: {
+                        assert: require.resolve('next/dist/compiled/assert'),
+                        buffer: require.resolve('next/dist/compiled/buffer/'),
+                        constants: require.resolve(
+                          'next/dist/compiled/constants-browserify'
+                        ),
+                        crypto: require.resolve(
+                          'next/dist/compiled/crypto-browserify'
+                        ),
+                        domain: require.resolve(
+                          'next/dist/compiled/domain-browser'
+                        ),
+                        http: require.resolve('next/dist/compiled/stream-http'),
+                        https: require.resolve(
+                          'next/dist/compiled/https-browserify'
+                        ),
+                        os: require.resolve('next/dist/compiled/os-browserify'),
+                        path: require.resolve(
+                          'next/dist/compiled/path-browserify'
+                        ),
+                        punycode: require.resolve(
+                          'next/dist/compiled/punycode'
+                        ),
+                        process: require.resolve('./polyfills/process'),
+                        // Handled in separate alias
+                        querystring: require.resolve(
+                          'next/dist/compiled/querystring-es3'
+                        ),
+                        stream: require.resolve(
+                          'next/dist/compiled/stream-browserify'
+                        ),
+                        string_decoder: require.resolve(
+                          'next/dist/compiled/string_decoder'
+                        ),
+                        sys: require.resolve('next/dist/compiled/util/'),
+                        timers: require.resolve(
+                          'next/dist/compiled/timers-browserify'
+                        ),
+                        tty: require.resolve(
+                          'next/dist/compiled/tty-browserify'
+                        ),
+                        // Handled in separate alias
+                        // url: require.resolve('url/'),
+                        util: require.resolve('next/dist/compiled/util/'),
+                        vm: require.resolve('next/dist/compiled/vm-browserify'),
+                        zlib: require.resolve(
+                          'next/dist/compiled/browserify-zlib'
+                        ),
+                        events: require.resolve('next/dist/compiled/events/'),
+                        setImmediate: require.resolve(
+                          'next/dist/compiled/setimmediate'
+                        ),
+                      },
+                    },
+                  },
+                ],
+              },
+            ]
+          : []),
       ].filter(Boolean),
     },
     plugins: [

packages/next/server/web/sandbox/context.ts

@@ -210,7 +210,6 @@ function createContext(options: {
     File,
     FormData,
     process: {
-      ...polyfills.process,
       env: buildEnvironmentVariablesFrom(options.env),
     },
     ReadableStream,

packages/next/server/web/sandbox/polyfills.ts

@@ -1,7 +1,6 @@
 import { Crypto as WebCrypto } from 'next/dist/compiled/@peculiar/webcrypto'
 import { CryptoKey } from 'next/dist/compiled/@peculiar/webcrypto'
 import { v4 as uuid } from 'next/dist/compiled/uuid'
-import processPolyfill from 'next/dist/compiled/process'
 
 import crypto from 'crypto'
 
@@ -13,7 +12,7 @@ export function btoa(str: string) {
   return Buffer.from(str, 'binary').toString('base64')
 }
 
-export { CryptoKey, processPolyfill as process }
+export { CryptoKey }
 
 export class Crypto extends WebCrypto {
   // @ts-ignore Remove once types are updated and we deprecate node 12

test/integration/middleware/core/test/index.test.js

@@ -131,6 +131,8 @@ describe('Middleware base tests', () => {
           env: {
             MIDDLEWARE_TEST: 'asdf',
           },
+          // it's poflyfilled since there is the "process" module
+          // as a devDepencies of the next package
           nextTick: 'function',
         },
       })

test/integration/middleware/with-builtin-module/pages/using-child-process/_middleware.js

@@ -0,0 +1,7 @@
+import { NextResponse } from 'next/server'
+import { spawn } from 'child_process'
+
+export async function middleware(request) {
+  console.log(spawn('ls', ['-lh', '/usr']))
+  return NextResponse.next()
+}

test/integration/middleware/with-builtin-module/pages/using-path/_middleware.js

@@ -0,0 +1,7 @@
+import { NextResponse } from 'next/server'
+import { basename } from 'path'
+
+export async function middleware(request) {
+  console.log(basename('/foo/bar/baz/asdf/quux.html'))
+  return NextResponse.next()
+}

test/integration/middleware/with-builtin-module/test/index.test.js

@@ -0,0 +1,90 @@
+/* eslint-env jest */
+
+import stripAnsi from 'next/dist/compiled/strip-ansi'
+import { join } from 'path'
+import {
+  fetchViaHTTP,
+  findPort,
+  killApp,
+  launchApp,
+  nextBuild,
+  waitFor,
+} from 'next-test-utils'
+
+const context = {}
+const WEBPACK_BREAKING_CHANGE = 'BREAKING CHANGE:'
+
+jest.setTimeout(1000 * 60 * 2)
+context.appDir = join(__dirname, '../')
+
+describe('Middleware importing Node.js built-in module', () => {
+  function getModuleNotFound(name) {
+    return `Module not found: Can't resolve '${name}'`
+  }
+
+  function getBuiltinApisNotSupported(name) {
+    return `Native Node.js APIs are not supported in the Edge Runtime. Found \`${name}\` imported.\n`
+  }
+
+  describe('dev mode', () => {
+    let output = ''
+
+    beforeAll(async () => {
+      context.appPort = await findPort()
+      context.app = await launchApp(context.appDir, context.appPort, {
+        env: { __NEXT_TEST_WITH_DEVTOOL: 1 },
+        onStdout(msg) {
+          output += msg
+        },
+        onStderr(msg) {
+          output += msg
+        },
+      })
+    })
+
+    beforeEach(() => (output = ''))
+    afterAll(() => killApp(context.app))
+
+    it('shows error when importing path module', async () => {
+      const res = await fetchViaHTTP(context.appPort, '/using-path')
+      await waitFor(500)
+      expect(res.status).toBe(500)
+      expect(output).toContain(getModuleNotFound('path'))
+      expect(output).toContain(getBuiltinApisNotSupported('path'))
+      expect(stripAnsi(output)).toContain("import { basename } from 'path'")
+      expect(output).not.toContain(WEBPACK_BREAKING_CHANGE)
+    })
+
+    it('shows error when importing child_process module', async () => {
+      const res = await fetchViaHTTP(context.appPort, '/using-child-process')
+      await waitFor(500)
+      expect(res.status).toBe(500)
+      expect(output).toContain(getModuleNotFound('child_process'))
+      expect(output).toContain(getBuiltinApisNotSupported('child_process'))
+      expect(stripAnsi(output)).toContain(
+        "import { spawn } from 'child_process'"
+      )
+      expect(output).not.toContain(WEBPACK_BREAKING_CHANGE)
+    })
+  })
+
+  describe('production mode', () => {
+    let buildResult
+
+    beforeAll(async () => {
+      buildResult = await nextBuild(context.appDir, undefined, {
+        stderr: true,
+        stdout: true,
+      })
+    })
+
+    it('should have middleware error during build', () => {
+      expect(buildResult.stderr).toContain(getModuleNotFound('child_process'))
+      expect(buildResult.stderr).toContain(getModuleNotFound('path'))
+      expect(buildResult.stderr).toContain(
+        getBuiltinApisNotSupported('child_process')
+      )
+      expect(buildResult.stderr).not.toContain(WEBPACK_BREAKING_CHANGE)
+    })
+  })
+})