* Do not exclude internal _next request in middleware
* Allow for `NextURL` to parse prefetch requests
* Add test for middleware data prefetch
* Refactor `hasBasePath` and `replaceBasePath`
* Refactor `removeTrailingSlash`
* Refactor parsed next url to use `getNextPathnameInfo`
* Allow to configure `NextURL`
* Ensure middleware rewrites with always with a locale
Co-authored-by: JJ Kasper <jj@jjsweb.site>
Hello! Thanks for making next.js so great.
## Bug
Right now, these types give false confidence. These `key`s are treated as though [a value is defined for _every_ string](https://dev.to/sarioglu/avoiding-unintended-undefined-values-while-using-typescript-record-4igo). However, given an arbitrary request, a particular cookie or query param could be `undefined`.
For example, when building an `/api` endpoint, the code might look like this:
```ts
import type { NextApiRequest, NextApiResponse } from "next"
export default function handler(req: NextApiRequest, res: NextApiResponse) {
// According to the old types, `value` is a string
const value = req.cookies.value
// Type-checking passes but leads to a runtime error when no `value` cookie is provided in the request
// Uncaught TypeError: Cannot read property 'toLowerCase' of undefined
value.toLowerCause()
// ...
}
```
By using `Partial`, TypeScript now knows that these objects don't have values defined for every `key` and accessing a given `key` might resolve to `undefined`.
---
The only obvious error this caused within this repo was on line 333 of the same file. For better or worse, I ended up casting that cookie value to a `string`. There's a series of `if` statements before it that, I guess, are guaranteeing that it's truly a string. Potentially, that stretch could be refactored such that TypeScript _knows_ it's a string.
Also, I tried to follow the contributing guidelines. However, running `yarn types` kicked out a bunch of errors about overwriting files:
```
$ yarn types
yarn run v1.22.10
$ lerna run types --stream
lerna notice cli v4.0.0
lerna info Executing command in 2 packages: "yarn run types"
@next/env: $ tsc index.ts --declaration --emitDeclarationOnly --declarationDir types --esModuleInterop
next: $ tsc --declaration --emitDeclarationOnly --declarationDir dist
next: error TS5055: Cannot write file '/Users/mbrandly/code/next.js/packages/next/dist/build/index.d.ts' because it would overwrite input file.
next: error TS5055: Cannot write file '/Users/mbrandly/code/next.js/packages/next/dist/build/webpack/plugins/build-manifest-plugin.d.ts' because it would overwrite input file.
...
...
...
```
Let me know if there's anything I can improve here! Thanks again.
This PR brings some significant refactoring in preparation for upcoming middleware changes. Each commit can be reviewed independently, here is a summary of what each one does and the reasoning behind it:
- [Move pagesDir to next-dev-server](f2fe154c00) simply moves the `pagesDir` property to the dev server which is the only place where it is needed. Having it for every server is misleading.
- [Move (de)normalize page path utils to a file page-path-utils.ts](27cedf0871) Moves the functions to normalize and denormalize page paths to a single file that is intended to hold every utility function that transforms page paths. Since those are complementary it makes sense to have them together. I also added explanatory comments on why they are not idempotent and examples for input -> output that I find very useful.
- [Extract removePagePathTail](6b121332aa) This extracts a function to remove the tail on a page path (absolute or relative). I'm sure there will be other contexts where we can use it.
- [Extract getPagePaths and refactor findPageFile](cf2c7b842e) This extracts a function `getPagePaths` that is used to generate an array of paths to inspect when looking for a page file from `findPageFile`. Then it refactors such function to use it parallelizing lookups. This will allow us to print every path we look at when looking for a file which can be useful for debugging. It also adds a `flatten` helper.
- [Refactor onDemandEntryHandler](4be685c37e) I've found this one quite difficult to understand so it is refactored to use some of the previously mentioned functions and make it easier to read.
- [Extract absolutePagePath util](3bc0783474) Extracts yet another util from the `next-dev-server` that transforms an absolute path into a page name. Of course it adds comments, parameters and examples.
- [Refactor MiddlewarePlugin](c595a2cc62) This is the most significant change. The logic here was very hard to understand so it is totally redistributed with comments. This also removes a global variable `ssrEntries` that was deprecated in favour of module metadata added to Webpack from loaders keeping less dependencies. It also adds types and makes a clear distinction between phases where we statically analyze the code, find metadata and generate the manifest file cc @shuding @huozhi
EDIT:
- [Split page path utils](158fb002d0) After seeing one of the utils was being used by the client while it was defined originally in the server, with this PR we are splitting the util into multiple files and moving it to `shared/lib` in order to make explicit that those can be also imported from client.
This fixes our `basePath` detection/replacing server-side as we were incorrectly considering `/docss` a match for a `basePath` of `/docs` which caused us to have an unexpected value in the `normalizeLocalePath` function.
- Fixes#22429
- Regression introduced in #17757
- Fixes: https://github.com/vercel/next.js/issues/31423
Co-authored-by: JJ Kasper <22380829+ijjk@users.noreply.github.com>
This PR adds support for [Middleware as per RFC ](https://github.com/vercel/next.js/discussions/29750).
## 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
Currently there is a lot of mutation in the Next.js Server and the checks for Locale are directly coded in the general request handler. Ideally, we should have a function where we just pass the request input (url + headers + config) and generate a bunch of metadata that analyzes it generating all metadata we might require for both the URL and i18n + basePath information.
This PR brings:
- A new parsing function `parseUrl` that joins parsing an absolute/relative URL into a data structure compatible with the Node parsing output but missing redundant properties.
- A wrapper `parseNextURL` that extends `parseUrl` analyzing `i18n` and `basePath` based on the provided configuration, url and headers. This function is pure and stateless so it can be used outside of the Next.js context.
- Types improvements and reuse.
- Refactors `next-server.ts` request handling using the above mentioned functions so that the code there just apply effects to the `req` object and the `parsedUrl.query` leaving the code much more straightforward.
- Refactors `getRouteRegex` decomposing in two different functions where `getParametrizedRoute` can be used to retrieve the serializable data that is used to generate the Regex.
