This updates to have a separate routing process and separate rendering
processes for `pages` and `app` so that we can properly isolate the two
since they rely on different react versions.
Besides allowing the above mentioned isolation this also helps us
control recovering from process crashes easier as pieces are more
isolated from one another e.g. an infinite loop during rendering will no
longer block the compiler and can be stopped/restarted as needed.
In follow-up PRs we will continue to separate out the routing logic from
the rendering logic so that each process only loads what is relevant to
it helping simplify the flow for requests regardless of type.
---------
Co-authored-by: Shu Ding <g@shud.in>
Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>
## What's in there?
The Edge runtime [does not support Node.js modules](https://edge-runtime.vercel.app/features/available-apis#unsupported-apis).
When building Next.js application, we currently fail the build when detecting node.js module imported from middleware.
This is an blocker for using code that is conditionally loading node.js modules (based on platform/env detection), as @cramforce reported.
This PR implements a new strategy where:
- we can build such middleware/Edge API route code **with a warning**
- we fail at run time, with graceful errors in dev (console & react-dev-overlay error)
- we fail at run time, with console errors in production
## How to test?
All cases are covered with integration tests.
To try them live, create a simple app with a page, a `middleware.js` file and a `pages/api/route.js`file.
Here are iconic examples:
### node.js modules
```js
// middleware.js
import { NextResponse } from 'next/server'
// static
import { basename } from 'path'
export default async function middleware() {
// dynamic
const { basename } = await import('path')
basename()
return NextResponse.next()
}
export const config = { matcher: '/' }
```
```js
// pags/api/route.js
// static
import { isAbsolute } from 'path'
export default async function handle() {
// dynamic
const { isAbsolute } = await import('path')
return Response.json({ useNodeModule: isAbsolute('/test') })
}
export const config = { runtime: 'experimental-edge' }
```
Desired error (+ source code highlight in dev):
> The edge runtime does not support Node.js 'path' module
Learn More: https://nextjs.org/docs/messages/node-module-in-edge-runtime
Desired warning at build time:
> A Node.js module is loaded ('path' at line 2) which is not supported in the Edge Runtime.
Learn More: https://nextjs.org/docs/messages/node-module-in-edge-runtime
- [x] in dev middleware, static, shows desired error on stderr
- [x] in dev route, static, shows desired error on stderr
- [x] in dev middleware, dynamic, shows desired error on stderr
- [x] in dev route, dynamic, shows desired error on stderr
- [x] in dev middleware, static, shows desired error on react error overlay
- [x] in dev route, static, shows desired error on react error overlay
- [x] in dev middleware, dynamic, shows desired error on react error overlay
- [x] in dev route, dynamic, shows desired error on react error overlay
- [x] builds middleware successfully, shows build warning, shows desired error on stderr on call
- [x] builds route successfully, shows build warning, shows desired error on stderr on call
### 3rd party modules not found
```js
// middleware.js
import { NextResponse } from 'next/server'
// static
import Unknown from 'unknown'
export default async function middleware() {
// dynamic
const Unknown = await import('unknown')
new Unknown()
return NextResponse.next()
}
```
export const config = { matcher: '/' }
```
```js
// pags/api/route.js
// static
import Unknown from 'unknown'
export default async function handle() {
// dynamic
const Unknown = await import('unknown')
return Response.json({ use3rdPartyModule: Unknown() })
}
export const config = { runtime: 'experimental-edge' }
```
Desired error (+ source code highlight in dev):
> Module not found: Can't resolve 'does-not-exist'
Learn More: https://nextjs.org/docs/messages/module-not-found
- [x] in dev middleware, static, shows desired error on stderr
- [x] in dev route, static, shows desired error on stderr
- [x] in dev middleware, dynamic, shows desired error on stderr
- [x] in dev route, dynamic, shows desired error on stderr
- [x] in dev middleware, static, shows desired error on react error overlay
- [x] in dev route, static, shows desired error on react error overlay
- [x] in dev middleware, dynamic, shows desired error on react error overlay
- [x] in dev route, dynamic, shows desired error on react error overlay
- [x] fails to build middleware, with desired error on stderr
- [x] fails to build route, with desired error on stderr
### unused node.js modules
```js
// middleware.js
import { NextResponse } from 'next/server'
export default async function middleware() {
if (process.exit) {
const { basename } = await import('path')
basename()
}
return NextResponse.next()
}
```
```js
// pags/api/route.js
export default async function handle() {
if (process.exit) {
const { basename } = await import('path')
basename()
}
return Response.json({ useNodeModule: false })
}
export const config = { runtime: 'experimental-edge' }
```
Desired warning at build time:
> A Node.js module is loaded ('path' at line 2) which is not supported in the Edge Runtime.
Learn More: https://nextjs.org/docs/messages/node-module-in-edge-runtime
- [x] invoke middleware in dev with no error
- [x] invoke route in dev with no error
- [x] builds successfully, shows build warning, invoke middleware with no error
- [x] builds successfully, shows build warning, invoke api-route with no error
## Notes to reviewers
The strategy to implement this feature is to leverages webpack [externals](https://webpack.js.org/configuration/externals/#externals) and run a global `__unsupported_module()` function when using a node.js module from edge function's code.
For the record, I tried using [webpack resolve.fallback](https://webpack.js.org/configuration/resolve/#resolvefallback) and [Webpack.IgnorePlugin](https://webpack.js.org/plugins/ignore-plugin/) but they do not allow throwing proper errors at runtime that would contain the loaded module name for reporting.
`__unsupported_module()` is defined in `EdgeRuntime`, and returns a proxy that's throw on use (whether it's property access, function call, new operator... synchronous & promise-based styles).
However there's an issue with error reporting: webpack does not includes the import lines in the generated sourcemaps, preventing from displaying useful errors.
I extended our middleware-plugin to supplement the sourcemaps (when analyzing edge function code, it saves which module is imported from which file, together with line/column/source)
The react-dev-overlay was adapted to look for this additional information when the caught error relates to modules, instead of looking at sourcemaps.
I removed the previous mechanism (built by @nkzawa ) which caught webpack errors at built time to change the displayed error message (files `next/build/index.js`, `next/build/utils.ts` and `wellknown-errors-plugin`)
