Skip build-time dynamic code checks for specific polyfills in the Edg…

…e runtime (#52009)

As discussed in https://vercel.slack.com/archives/C03ENM5HB4K/p1687999628589119 and #51910, it makes sense to have a known list for packages (mostly polyfills) that we know are having dynamic code (`eval`, `new Function`) but are safe to run in the Edge Runtime because that dynamic code will never be executed.

packages/next/src/build/webpack/plugins/middleware-plugin.ts

@@ -9,6 +9,7 @@ import { getModuleBuildInfo } from '../loaders/get-module-build-info'
 import { getSortedRoutes } from '../../../shared/lib/router/utils'
 import { webpack, sources } from 'next/dist/compiled/webpack/webpack'
 import { isMatch } from 'next/dist/compiled/micromatch'
+import path from 'path'
 import {
   EDGE_RUNTIME_WEBPACK,
   EDGE_UNSUPPORTED_NODE_APIS,
@@ -29,6 +30,9 @@ import { normalizeAppPath } from '../../../shared/lib/router/utils/app-paths'
 import { INSTRUMENTATION_HOOK_FILENAME } from '../../../lib/constants'
 import { NextBuildContext } from '../../build-context'
 
+const KNOWN_SAFE_DYNAMIC_PACKAGES =
+  require('../../../lib/known-edge-safe-packages.json') as string[]
+
 export interface EdgeFunctionDefinition {
   files: string[]
   name: string
@@ -249,6 +253,16 @@ function isDynamicCodeEvaluationAllowed(
   middlewareConfig?: MiddlewareConfig,
   rootDir?: string
 ) {
+  // Some packages are known to use `eval` but are safe to use in the Edge
+  // Runtime because the dynamic code will never be executed.
+  if (
+    KNOWN_SAFE_DYNAMIC_PACKAGES.some((pkg) =>
+      fileName.includes(`/node_modules/${pkg}/`.replace(/\//g, path.sep))
+    )
+  ) {
+    return true
+  }
+
   const name = fileName.replace(rootDir ?? '', '')
   return isMatch(name, middlewareConfig?.unstable_allowDynamicGlobs ?? [])
 }

packages/next/src/lib/known-edge-safe-packages.json

@@ -0,0 +1 @@
+["function-bind"]

test/production/edge-safe-dynamic-code/index.test.ts

@@ -0,0 +1,41 @@
+import { createNext } from 'e2e-utils'
+import { NextInstance } from 'test/lib/next-modes/base'
+
+// This test is basically for https://github.com/vercel/next.js/discussions/51910
+// to make sure that some libs that we know are using `eval` but don't break
+// because it will never run into that condition, but still can't to be DCE'd.
+
+describe('Edge safe dynamic code', () => {
+  let next: NextInstance
+
+  afterAll(() => next.destroy())
+
+  it('should not fail when "function-bind" package is used', async () => {
+    next = await createNext({
+      skipStart: true,
+      dependencies: {
+        'function-bind': 'latest',
+      },
+      files: {
+        'pages/index.js': `
+          export default function Page() { 
+            return <p>hello world</p>
+          } 
+        `,
+        'middleware.js': `
+          import { NextResponse } from 'next/server'
+          import * as bind from 'function-bind'
+          console.log(bind)
+          export default async function middleware(request) {
+            return NextResponse.next()
+          }
+        `,
+      },
+    })
+    await next.start()
+
+    expect(next.cliOutput).not.toContain(
+      `Dynamic Code Evaluation (e. g. 'eval', 'new Function', 'WebAssembly.compile') not allowed in Edge Runtime`
+    )
+  })
+})