## Bug
- [x] Fixes#38047
- ~[ ] Integration tests added: do you want them added for such an unusual edge case?~ [Comment below: skipping](https://github.com/vercel/next.js/pull/38046#issuecomment-1207444526)
- [x] Errors have helpful link attached, see `contributing.md`: ~I'll wait until this approach & error message are confirmed before thinking more deeply on how to explain the error~
Sending a draft PR as reference ahead of time. 🙂
Doesn't resolve the root issue of why `_devPagesManifest.json` might fail to load. But does improve the log for when it happens. I'd suggest applying this same fix to `_devMiddlewareManifest.json` too.
<table>
<thead>
<tr>
<th></th>
<th>Before</th>
<th>After</th>
</tr>
</thead>
<tbody>
<tr>
<th>Console</th>
<td>
<pre>
<code>
Failed to fetch devPagesManifest TypeError: Failed to fetch
at PageLoader.getPageList (page-loader.js?e87a:30:53)
at _callee$ (router.js?8684:955:45)
at ...
</code>
</pre>
<pre>
<code>
router.js?8684:1319 Uncaught (in promise) TypeError: Cannot \
read properties of undefined (reading 'includes')
at resolveDynamicRoute (router.js?8684:1319:16)
at _callee$
at ...
</code>
</pre>
</td>
<td>
<pre>
<code>
Failed to fetch devPagesManifest: TypeError: Failed to fetch
at PageLoader.getPageList (page-loader.js?e87a:30:53)
at _callee$ (router.js?8684:955:45)
at ...
</code>
</pre>
</td>
</tr>
<tr>
<th>Visual</th>
<td><img alt="Screenshot of a Next.js runtime error: TypeError: Cannot read properties of undefined (reading 'includes')" src="https://user-images.githubusercontent.com/3335181/175854728-8d5c2051-1229-4da7-8af1-fc95236befae.png" /></td>
<td><img alt="Screenshot of a Next.js runtime error: Error: Failed to fetch _devPagesManifest.json. Is something blocking that network request?" src="https://user-images.githubusercontent.com/3335181/175854774-07895846-1a1c-4bb8-bf57-fa696b8c6ba4.png" /></td>
</tr>
</tbody>
</table>
## Bug
- [x] Related issues linked using `fixes #number`
- [x] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`
Fixes#38743.
Fixes: https://github.com/vercel/next.js/pull/38750
The PR adds basic `TemplateLiteral` support for static analysis.
The corresponding re-production of #38743 has also been implemented in e2e tests.
* Add next.config.js validation with ajv
* update manifest
* update lib type
* remove old tests
* update to pre-build validation code
* ensure validate output is ncced
* Apply suggestions from code review
Co-authored-by: Steven <steven@ceriously.com>
* Add example of typing next.config.js
Co-authored-by: Steven <steven@ceriously.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`)
Readds `@next/next/no-assign-module-variable` ESLint rule that was inadvertently removed in #34335 during the resolution of many merge conflicts.
This PR will get us back to a good / working state. I'll see if I can add a test to ensure all rule are accounted for in a separate PR.
Fixes#34335.
## Bug
- [x] Related issues linked using `fixes #number`
- [x] Integration tests added
- [x] Errors have helpful link attached, see `contributing.md`
## Documentation / Examples
- [x] Make sure the linting passes by running `pnpm lint`
- [x] The examples guidelines are followed from [our contributing doc](https://github.com/vercel/next.js/blob/canary/contributing.md#adding-examples)
* Update middleware upgrade guide w/ more rationale
The API changes for GA are general improvements.
Our middleware upgrade guide is very helpful about describing the changes
that were made and how to react to them; include some additional "why" to
rationalize these changes.
* Update middleware-upgrade-guide.md
Avoid words like "simple" and "easy"
* Update middleware-upgrade-guide.md
Clarify the issues around "security" with responses - the previous verbiage made it sound like there was a security vulnerability; there was not.
* Apply suggestions from code review
Co-authored-by: Lee Robinson <me@leerob.io>
* Apply suggestions from code review
* Update errors/middleware-upgrade-guide.md
* Update errors/middleware-upgrade-guide.md
Co-authored-by: Balázs Orbán <info@balazsorban.com>
* Apply suggestions from code review
* Update canary -> latest
* Apply suggestions from code review
Co-authored-by: Lee Robinson <me@leerob.io>
Co-authored-by: Balázs Orbán <info@balazsorban.com>
Co-authored-by: JJ Kasper <jj@jjsweb.site>
It is possible that users that are defining `src/pages` in their project confuse the "project root" to locate middleware with the actual project root instead of `src/middleware` so this PR rephrases the migration guide to make explicit that the it should be located **next** to the `pages` folder.
## Bug
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`
## Feature
- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have helpful link attached, see `contributing.md`
## Documentation / Examples
- [ ] Make sure the linting passes by running `pnpm lint`
- [ ] The examples guidelines are followed from [our contributing doc](https://github.com/vercel/next.js/blob/canary/contributing.md#adding-examples)
Co-authored-by: JJ Kasper <22380829+ijjk@users.noreply.github.com>
This PR introduces a new experimental component, `next/future/image`, which is inspired by the existing experimental `layout="raw"`.
The difference is that much of the code has been deleted in order to reduce client-side code as well as reduce complexity:
- No `layout` prop
- No `loader` config (although `loader` prop works)
- No `IntersectionObserver`, use native `loading="lazy"`
- No `lazyBoundary`
- No `lazyRoot`
- No `fill` (yet) so width & height are required
- No `objectFit` (use `style` instead)
- No `objectPosition` (use `style` instead)
This improves performance because native `loading="lazy"` doesn't need to wait for React Hydration and client-side JS.
In a future PR, we will modify `next/image` to remove `layout="raw"` since this new component supersedes it.
## Feature
- [x] Integration tests added
- [x] Documentation added
- [x] Telemetry added. In case of a feature if it's used or not.
- [x] Errors have helpful link attached, see `contributing.md`
Feedback:
> Hello :D may it be that the types should be imported in a TS file, so I think the extension of the file should be updated here :) /middleware.js -> /middleware.ts (or no types)
In a previous PR (#19032), we added a hard error during `next export` if the default Image Optimization API is being used because it requires a server to optimized on demand. The error message offers several different solutions but it didn't consider that by the time someone runs `next export`, they are probably done writing their app.
So if `next export` is a hard requirement, the quickest path forward is to disable Image Optimization API. So this PR adds a new configuration option to `next.config.js`:
```js
module.exports = {
images: {
unoptimized: true
}
}
```
### Update
Upon further discussion, we might want to avoid doing this just for images and instead introduce a top-level config to indicate export is coming and then handle errors or warn for [unsupported features](https://nextjs.org/docs/advanced-features/static-html-export#unsupported-features).
```
module.exports = {
nextExport: true
}
```
Co-authored-by: JJ Kasper <22380829+ijjk@users.noreply.github.com>
In Middlewares, dynamic code execution is not allowed. Currently, we warn if eval / new Function are invoked in dev but don't warn another dynamic code execution in WebAssembly.
This PR adds warnings for `WebAssembly.compile` and `WebAssembly.instantiate` with a buffer parameter (note that `WebAssembly.instantiate` with a **module** parameter is legit) invocations. Note that other methods that compile WASM dynamically such as `WebAssembly.compileStreaming` are not exposed to users so we don't need to cover them.
## Bug
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`
## Feature
- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [x] Integration tests added
- [x] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [x] Errors have helpful link attached, see `contributing.md`
## Documentation / Examples
- [ ] Make sure the linting passes by running `pnpm lint`
- [ ] The examples guidelines are followed from [our contributing doc](https://github.com/vercel/next.js/blob/canary/contributing.md#adding-examples)
Co-authored-by: JJ Kasper <22380829+ijjk@users.noreply.github.com>
[Recent changes](https://github.com/vercel/next.js/pull/31936) to `next/script` introduced the capability to use `beforeInteractive` scripts in the custom document. This old error message is incorrect.
This PR builds on the work from @hattakdev (PR went stale: https://github.com/vercel/next.js/pull/14499) and adds a new `integration` test for the new warning.
## Bug
- [x] Related issues linked using `fixes #number`
- [x] Integration tests added
- [x] Errors have helpful link attached, see `contributing.md`
## To run locally
1. `pnpm build`
2. `pnpm testonly test/integration/export-getInitialProps-warn/test/index.test.js`
Fixes#13946
## Notes
<details>
<summary>Click to toggle see</summary>
I know the `contributing.md` doc said to avoid adding new tests to `integration`. It also said new tests should be written in TypeScript.
I wasn't sure where to put the tests for this so I went with `integration`. I also didn't see many other tests written in TS in this part of the codebase so I stuck with `.js`.
</details>
Co-authored-by: JJ Kasper <22380829+ijjk@users.noreply.github.com>
This PR moves the internal logic associated with `req.ua` into an explicit method the user should to call to have the same behavior.
**before**
```typescript
// middleware.ts
import { NextRequest, NextResponse } from 'next/server'
export function middleware(request: NextRequest) {
const url = request.nextUrl
const viewport = request.ua.device.type === 'mobile' ? 'mobile' : 'desktop'
url.searchParams.set('viewport', viewport)
return NextResponse.rewrites(url)
}
```
**after**
```typescript
// middleware.ts
import { NextRequest, NextResponse, userAgent } from 'next/server'
export function middleware(request: NextRequest) {
const url = request.nextUrl
const { device } = userAgent(request)
const viewport = device.type === 'mobile' ? 'mobile' : 'desktop'
url.searchParams.set('viewport', viewport)
return NextResponse.rewrites(url)
}
```
This potentially will save the extra 17 kB related to the size of `ua-parser-js`
## What
This changes the` class` attribute with `className`
## Why
Class is a reserved word in JavaScript. The appropriate attribute to use is `className`.
## Bug
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`
## Feature
- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have helpful link attached, see `contributing.md`
## Documentation / Examples
- [ ] Make sure the linting passes by running `yarn lint`
Missing close parenthesis on docs example from page custom-document-image-import.md
## Bug
- [x] Related issues linked using `fixes #37155`
- [ ] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`
## Feature
- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have helpful link attached, see `contributing.md`
## Documentation / Examples
- [ ] Make sure the linting passes by running `yarn lint`
Co-authored-by: JJ Kasper <22380829+ijjk@users.noreply.github.com>
_Hello Next.js team! First PR here, I hope I've followed the right practices._
### What's in there?
It has been decided to only support the following uses cases in Next.js' middleware:
- rewrite the URL (`x-middleware-rewrite` response header)
- redirect to another URL (`Location` response header)
- pass on to the next piece in the request pipeline (`x-middleware-next` response header)
1. during development, a warning on console tells developers when they are returning a response (either with `Response` or `NextResponse`).
2. at build time, this warning becomes an error.
3. at run time, returning a response body will trigger a 500 HTTP error with a JSON payload containing the detailed error.
All returned/thrown errors contain a link to the documentation.
This is a breaking feature compared to the _beta_ middleware implementation, and also removes `NextResponse.json()` which makes no sense any more.
### How to try it?
- runtime behavior: `HEADLESS=true yarn jest test/integration/middleware/core`
- build behavior : `yarn jest test/integration/middleware/build-errors`
- development behavior: `HEADLESS=true yarn jest test/development/middleware-warnings`
### Notes to reviewers
The limitation happens in next's web adapter. ~The initial implementation was to check `response.body` existence, but it turns out [`Response.redirect()`](https://github.com/vercel/next.js/blob/canary/packages/next/server/web/spec-compliant/response.ts#L42-L53) may set the response body (https://github.com/vercel/next.js/pull/31886). Hence why the proposed implementation specifically looks at response headers.~
`Response.redirect()` and `NextResponse.redirect()` do not need to include the final location in their body: it is handled by next server https://github.com/vercel/next.js/blob/canary/packages/next/server/next-server.ts#L1142
Because this is a breaking change, I had to adjust several tests cases, previously returning JSON/stream/text bodies. When relevant, these middlewares are returning data using response headers.
About DevEx: relying on AST analysis to detect forbidden use cases is not as good as running the code.
Such cases are easy to detect:
```js
new Response('a text value')
new Response(JSON.stringify({ /* whatever */ })
```
But these are false-positive cases:
```js
function returnNull() { return null }
new Response(returnNull())
function doesNothing() {}
new Response(doesNothing())
```
However, I see no good reasons to let users ship middleware such as the one above, hence why the build will fail, even if _technically speaking_, they are not setting the response body.
## Feature
- [x] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [x] Integration tests added
- [x] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [x] Errors have helpful link attached, see `contributing.md`
## Documentation / Examples
- [x] Make sure the linting passes by running `yarn lint`
This PR deprecates declaring a middleware under `pages` in favour of the project root naming it after `middleware` instead of `_middleware`. This is in the context of having a simpler execution model for middleware and also ships some refactor work. There is a ton of a code to be simplified after this deprecation but I think it is best to do it progressively.
With this PR, when in development, we will **fail** whenever we find a nested middleware but we do **not** include it in the compiler so if the project is using it, it will no longer work. For production we will **fail** too so it will not be possible to build and deploy a deprecated middleware. The error points to a page that should also be reviewed as part of **documentation**.
Aside from the deprecation, this migrates all middleware tests to work with a single middleware. It also splits tests into multiple folders to make them easier to isolate and work with. Finally it ships some small code refactor and simplifications.
* remove the experimental web vital hook api
* remove the exported flush effects api and only error on development, keep only usage to styled-jsx
for web vital hook API: The usage is not widly adopted since the existing exported vital api could do the same work. In the future we'll deprecate the `_app.server` in favor of `_app` in server component pages. so that this api won't be required.
for flush effects api: other css-in-js libs are not using the same approach like styled-jsx which holding a style registry and could flush it during streaming. emotion-js and styled-components are still relying on `Document.getInitialProps` atm and we have supported it in latest canary
This PR moves the instructions for configuring CI providers to preserve Next.js's build cache out of the _No Cache Detected_ error message and into ~the _Deployment_~ a new page within the _Advanced Features_ docs.
This change is beneficial because it makes the CI configuration examples visible in the context of other helpful documentation for deploying Next.js.
👉 **Prior to this change, these CI configuration examples didn't show up in the Next.js docs.**
The relocated instructions are now linked on the _No Cache Detected_ error message page.
## Documentation / Examples
- [x] Make sure the linting passes by running `yarn lint`
Co-authored-by: Lee Robinson <me@leerob.io>
Co-authored-by: Steven <steven@ceriously.com>
fixes#36763fixes#36590
## Feature
- [x] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- It hasn't been accepted for implementation, although that process isn't clear, and this is a pretty trivial fix.
- [x] Related issues linked using `fixes #number`
- [x] Integration tests added
- [x] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- This is somewhat inherent in the error log
- [x] Errors have helpful link attached, see `contributing.md`
## Documentation / Examples
- [x] Make sure the linting passes by running `yarn lint`
## Description
This PR implements a new configuration object in `next.config.js` called `experimental.images.remotePatterns`.
This will eventually deprecate `images.domains` because it covers the same use cases and more by allowing wildcard pattern matching on `hostname` and `pathname` and also allows restricting `protocol` and `port`.
## Feature
- [x] Implements an existing feature request.
- [x] Related issues linked
- [x] Unit tests added
- [x] Integration tests added
- [x] Documentation added
- [x] Telemetry added. In case of a feature if it's used or not.
- [x] Errors have helpful link attached, see `contributing.md`
## Related
- Fixes#27925
- Closes#18429
- Closes#18632
- Closes#18730
- Closes#27345
Changes to the beforeInteractive strategy to make it work for streaming
Splitting `beforeInteractive` into two strategies `beforeInteractive` at the _document level and `beforePageRender` for page level <Scripts>
Josh Goldberg
