mirror of
https://github.com/vercel/next.js.git
synced 2026-09-20 02:25:18 +08:00
Jiwon Choi
bc59f210b0
This PR removes middleware docs and adds a "Migration to Proxy" section to the Proxy docs, which explains the rationale for the renaming to Proxy and provides a migration guide. Did not remove `middleware-upgrade-docs` as it's an upgrade doc from the legacy middleware. Below are untouched as they need codebase changes: - `instrumentation` docs - `onRequestError` has `context.routeType` as `'middleware'` - `adapterPath` docs - has `MiddlewareMatcher` type example - `ProxyConfig` - has a user-facing `MiddlewareMatcher` type --------- Co-authored-by: Joseph Chamochumbi <joseph.chamochumbi@vercel.com>
48 lines
1.7 KiB
Plaintext
48 lines
1.7 KiB
Plaintext
---
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title: Dynamic code evaluation is not available in Proxy
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---
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## Why This Error Occurred
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`eval()`, `new Function()` or compiling WASM binaries dynamically is not allowed in Proxy.
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Specifically, the following APIs are not supported:
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- `eval()`
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- `new Function()`
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- `WebAssembly.compile`
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- `WebAssembly.instantiate` with [a buffer parameter](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/WebAssembly/instantiate#primary_overload_%E2%80%94_taking_wasm_binary_code)
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## Possible Ways to Fix It
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You can bundle your WASM binaries using `import`:
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```ts filename="proxy.ts"
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import { NextResponse } from 'next/server'
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import squareWasm from './square.wasm?module'
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export default async function proxy() {
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const m = await WebAssembly.instantiate(squareWasm)
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const answer = m.exports.square(9)
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const response = NextResponse.next()
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response.headers.set('x-square', answer.toString())
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return response
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}
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```
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In rare cases, your code could contain (or import) some dynamic code evaluation statements which _can not be reached at runtime_ and which can not be removed by tree-shaking.
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You can relax the check to allow specific files with your Proxy [configuration](/docs/pages/api-reference/edge#unsupported-apis):
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```ts filename="pages/api/example.ts"
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export const config = {
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unstable_allowDynamic: [
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'/lib/utilities.js', // allows a single file
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'**/node_modules/function-bind/**', // use a glob to allow anything in the function-bind 3rd party module
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],
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}
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```
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`unstable_allowDynamic` is a glob, or an array of globs, ignoring dynamic code evaluation for specific files. The globs are relative to your application root folder.
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Be warned that if these statements are executed on the Edge, _they will throw and cause a runtime error_.
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