Hi,
- Remove inlined CSS style which have minor performance loss. And hoist it to top of the component.
> Each time you inline an object, React re-creates a new reference to this object on every render. This causes components that receive this object to treat it as a referentially different one which have some performance pitfalls.
_Extremely sorry if I made any mistakes :(_
This PR removes the default styling of `object-fit:"contain"` for images using the future image component. This means images will get the default `object-fit` behavior of `"fill"`.
The main reason for this change is that an inline style will take precedence over external CSS, making this default behavior difficult to override with some styling strategies.
Co-authored-by: Steven <229881+styfle@users.noreply.github.com>
Use flush effects to custom apply css-in-js solution to app. Re-introduce flush effects to app-render, and remove default support of styled-jsx in `app/`. So that users will choose their own css-in-js solution if they need any customization. styled-jsx won't appear in client bundle if you didn't use it.
For now we have to inject the initial styles before `</head>` to avoid hydration errors. Later on we can remove this once react can handle it.
- [x] inject styles before end of head element
- [x] add tests
This ensures we properly leverage the `assetPrefix` for `app`. Note for reviewing the test changes are mostly spacing so hiding that may help.
## Bug
- [x] Related issues linked using `fixes #number`
- [x] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`
Fixes: [slack thread](https://vercel.slack.com/archives/C035J346QQL/p1659387244559979)
This PR adds a `fill` attribute to the future image component, that behave similarly to the fill mode on the existing image component.
Functionally, it mainly adds `position: "absolute"` and `object-fit: "contain"` to the image element, along with `height: "100%"` and `width: "100%"` to preserve the image aspect ratio. All of these can be overwritten by the user, except for `position: "absolute"`, which will throw an error. This is because changing that property without height and width is likely to cause layout shift.
Because we no longer have the wrapper element, this new version of `fill` requires that the user set `overflow: "hidden"` on the parent element themself, if they want that behavior.
This PR also includes several runtime checks to catch instances where the fill mode may provide unexpected results. These runtime checks warn if:
* The image doesn't have the `sizes` attribute and loads much smaller than the viewport
* The containing element does not have `position: "relative"`
* The image height value is 0
Co-authored-by: Steven <229881+styfle@users.noreply.github.com>
x-ref #39199
The change in #39199 isn't correct. Middleware manifest should only contain middleware route, so that when router navigates, it only try to apply middleware instead of checking all edge routes. This PR also changes the middleware manifest global value from array to object for easier access
## Bug
- [ ] Related issues linked using `fixes #number`
- [x] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`
Add `next/dist/client/components/shared/dynamic` as shared api which server and client components can both support.
Dynamic imports will be part of flight on server side.
This pr doesn't contain preloading part for client components.
Closes: #30962
This PR adds a new `onReady` prop to `next/script` to handle shortcomings of the current `onLoad` prop. Some third-party providers and widgets require initialization code to run after the script's `load` event and every time the component is mounted. The `onReady` should solve that use case.
For more details, refer to the discussion in #30962.
CC @janicklas-ralph
## Bug
- [X] Related issues linked using `fixes #number`
- [X] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`
Co-authored-by: JJ Kasper <22380829+ijjk@users.noreply.github.com>
- Add additional comments for reducer functions.
- Add comments for CacheNode
## 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)
Expand explanation of new router.
## 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)
Expanded app-render.
## 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)
This adds handling for prefetching `onTouchStart` as this gives a little more time to start parsing required scripts for a page transition if not already done that can help make the transition faster. This is based on research showing the touch start event firing on average `90ms` before click (x-ref: [source](https://instant.page/#:~:text=in%20the%20world.-,On%20mobile,-A%20user%20starts))
This also adds testing safari with playwright so we can run these in PRs instead of only after merge and adds initial mobile testing as well.
x-ref: [slack thread](https://vercel.slack.com/archives/C7PDM7X2M/p1658250170774989?thread_ts=1658249275.178349&cid=C7PDM7X2M)
## 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)
Fixes the hash being overwritten when you open a page.
## 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>
## What’s in there?
This PR brings more consistency in how errors and warnings are reported when running code in the Edge Runtime:
- Dynamic code evaluation (`eval()`, `new Function()`, `WebAssembly.instantiate()`, `WebAssembly.compile()`…)
- Usage of Node.js global APIs (`BroadcastChannel`, `Buffer`, `TextDecoderStream`, `setImmediate()`...)
- Usage of Node.js modules (`fs`, `path`, `child_process`…)
The new error messages should mention *Edge Runtime* instead of *Middleware*, so they are valid in both cases.
It also fixes a bug where the process polyfill would issue a warning for `process.cwd` (which is `undefined` but legit). Now, one has to invoke the function `process.cwd()` to trigger the error.
It finally fixes the react-dev-overlay, where links from middleware and Edge API route files could not be opened because of the `(middleware)/` prefix in their name.
About the later, please note that we can’t easily remove the prefix or change it for Edge API routes. It comes from the Webpack layer, which is the same for both. We may consider renaming it to *edge* instead in the future.
## How to test?
These changes are almost fully covered with tests:
```bash
pnpm testheadless --testPathPattern runtime-dynamic
pnpm testheadless --testPathPattern runtime-with-node
pnpm testheadless --testPathPattern runtime-module
pnpm testheadless --testPathPattern middleware-dev-errors
```
To try them out manually, you can write a middleware and Edge route files like these:
```jsx
// middleware.js
import { NextResponse } from 'next/server'
import { basename } from 'path'
export default async function middleware() {
eval('2+2')
setImmediate(() => {})
basename()
return NextResponse.next()
}
export const config = { matcher: '/' }
```
```jsx
// pages/api/route.js
import { basename } from 'path'
export default async function handle() {
eval('2+2')
setImmediate(() => {})
basename()
return Response.json({ ok: true })
}
export const config = { runtime: 'experimental-edge' }
```
The expected behaviours are:
- [x] dev, middleware/edge route is using a node.js module: error at runtime (logs + read-dev-overlay):
```bash
error - (middleware)/pages/api/route.js (1:0) @ Object.handle [as handler]
error - The edge runtime does not support Node.js 'path' module.
Learn More: https://nextjs.org/docs/messages/node-module-in-edge-runtime
> 1 | import { basename } from "path";
2 | export default async function handle() {
```
- [x] build, middleware/edge route is using a node.js module: warning but succeeds
```bash
warn - Compiled with warnings
./middleware.js
A Node.js module is loaded ('path' at line 4) which is not supported in the Edge Runtime.
Learn More: https://nextjs.org/docs/messages/node-module-in-edge-runtime
./pages/api/route.js
A Node.js module is loaded ('path' at line 1) which is not supported in the Edge Runtime.
Learn More: https://nextjs.org/docs/messages/node-module-in-edge-runtime
```
- [x] production, middleware/edge route is using a node.js module: error at runtime (logs + 500 error)
```bash
Error: The edge runtime does not support Node.js 'path' module.
Learn More: https://nextjs.org/docs/messages/node-module-in-edge-runtime
at <unknown> (file:///Users/damien/dev/next.js/packages/next/server/web/sandbox/context.ts:149)
```
- [x] dev, middleware/edge route is using a node.js global API: error at runtime (logs + read-dev-overlay):
```bash
error - (middleware)/pages/api/route.js (4:2) @ Object.handle [as handler]
error - A Node.js API is used (setImmediate) which is not supported in the Edge Runtime.
Learn more: https://nextjs.org/docs/api-reference/edge-runtime
2 |
3 | export default async function handle() {
> 4 | setImmediate(() => {})
| ^
```
- [x] build, middleware/edge route is using a node.js global API: warning but succeeds
```bash
warn - Compiled with warnings
./middleware.js
A Node.js API is used (setImmediate at line: 6) which is not supported in the Edge Runtime.
Learn more: https://nextjs.org/docs/api-reference/edge-runtime
./pages/api/route.js
A Node.js API is used (setImmediate at line: 3) which is not supported in the Edge Runtime.
Learn more: https://nextjs.org/docs/api-reference/edge-runtime
```
- [x] production, middleware/edge route is using a node.js module: error at runtime (logs + 500 error)
```bash
Error: A Node.js API is used (setImmediate) which is not supported in the Edge Runtime.
Learn more: https://nextjs.org/docs/api-reference/edge-runtime
at <unknown> (file:///Users/damien/dev/next.js/packages/next/server/web/sandbox/context.ts:330)
```
- [x] dev, middleware/edge route is loading dynamic code: warning at runtime (logs + read-dev-overlay) and request succeeds (we allow dynamic code in dev only):
```bash
warn - (middleware)/middleware.js (7:2) @ Object.middleware [as handler]
warn - Dynamic Code Evaluation (e. g. 'eval', 'new Function') not allowed in Edge Runtime
5 |
6 | export default async function middleware() {
> 7 | eval('2+2')
```
- [x] build, middleware/edge route is loading dynamic code: build fails with error:
```bash
Failed to compile.
./middleware.js
Dynamic Code Evaluation (e. g. 'eval', 'new Function', 'WebAssembly.compile') not allowed in Edge Runtime
Used by default
./pages/api/route.js
Dynamic Code Evaluation (e. g. 'eval', 'new Function', 'WebAssembly.compile') not allowed in Edge Runtime
Used by default
```
## Notes to reviewers
Edge-related errors are either issued from `next/server/web/sandbox/context.ts` file (runtime errors) or from `next/build/webpack/plugins/middleware-plugin.ts` (webpack compilation).
The previous implementation (I’m pleading guilty here) was way too verbose: some errors (Node.js global APIs like using `process.cwd()`) could be reported several times, and the previous mechanism to dedupe them (in middleware-plugin) wasn’t really effective.
Changes in tests are due to renaming existing tests such as `test/integration/middleware-with-node.js-apis` into `test/integration/edge-runtime-with-node.js-apis`. I extended them to cover Edge API route.
@hanneslund I’ve pushed the improvement you did in https://github.com/vercel/next.js/pull/38289/ one step further to avoid duplication.
Drop the `next/streaming` endpoint. Currently it only holds the only one experimental api and we'd like to deprecate it in favor of oher future APIs for app dir
Currently, when a user forgets the `src` prop on an image, an error is thrown. However that error doesn't include any of the the user's code in the stack trace, so its nearly impossible to figure out which image is the culprit if there are multiple images on the page.
Since this error only throws on demand when a page is visited during `next dev`, we can instead delay the error so it no longer prints on the server but prints on mount instead. At that point, we'll have the `<img>` element via ref and can print it to the web console with the stack trace.
- Fixes#23742
I noticed our internal comments about exported functions that should not be used in application code.
TSDoc has the [`@internal`](https://tsdoc.org/pages/tags/internal/) option that can be used together with TS's [`stripInternal: true` compiler option](https://www.typescriptlang.org/tsconfig/#stripInternal), hiding these from inferred types:
Before:
After:
It would also be great to use `/**/` comments instead of `//` when documenting methods/properties/functions, as these can be picked up by the editor when referring to these, so someone new to the codebase will hopefully have to jump around less to get some useful comments.
## 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)
Ensures the `<html>` is not wrapped in an extra div when the root layout is nested in a route group.
## 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)
Follow-up to #38682. Instead of checking if the full element is in the viewport we only check if the top of the element is in the viewport. If it is not we have to scroll back up in cases of navigating between items in the same layout for example.
* test: added some test cases for new client side router
* tests: added additional test cases
* test: improved test support
* feat: added support for `<Link soft />`
* tests: improved test reliability
* tests: added more cases for catch-all routes
* tests: added app -> pages -> app tests
* tests: add tests for useCookies + useHeaders
* tests: added tests for usePreviewData
* tests: added more tests for hooks and client components
* tests: added tests for query/params handling
* tests: fix tests for param/query to use props
* tests: added some skipped tests for unimplemented features
* tests: linting
* refactor: updated TODO -> TODO-APP
* tests: added some more test cases
* tests: skipped failing test
Temporarily we need to ensure that `<link>` tags are injected to `<head>` in the stream.
## 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)
Went through the todos I had added while implementing the new router and removes everything that is now covered.
## 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)
The current timing (after chunk loaded) isn't accurate enough because React hydrates asynchronously.
## 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: Jiachi Liu <4800338+huozhi@users.noreply.github.com>
Temporary fix for refreshing of serverContext. We'll want to make a change for development with `createServerContext` to React itself in the future.
## 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)
In certain cases, mini-css-extractor will create independent `CSSModule` to the module graph, which doesn't have a user request or resource. Hence we can't match them in the flight manifest plugin like before. This PR adds a work around to use `mod.type` and `mod._identifier` to get such CSS assets.
## 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)
* inject the link tags before page content in layout router
* fix flight handling during client navigation
* fix buffering
Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>
Renames todos to split them / make it easier to find what has to be done for the new router.
## 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)
Handles the case where an error is introduced which causes a Fast Refresh and then it's fixed.
## 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)
* Enable css in server components
* inject server css into flight
* refactor and fix test
* fix lint
* resolve css from module deps
* fix dev & prod inconsistentce, collect client css
* simplify
* dedupe duplicated css chunks
* remove ssr link injection and css flight
Co-authored-by: Shu Ding <g@shud.in>
Handles the case where you navigate between routes in `pages` and `app`.
## 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)
- Remove cache value that was incorrectly nested deeper
- Remove extra useEffect (already applied during hydration based on the `useReducer` input)
- Add dynamic parameter name into the tree
Follow-up to #37551, cleans up some code and prepares for catch-all and optional catch-all routes.
## Client-side router for `app` directory
This PR implements the new router that leverages React 18 concurrent features like Suspense and startTransition.
It also integrates with React Server Components and builds on top of it to allow server-centric routing that only renders the part of the page that has to change.
It's one of the pieces of the implementation of https://nextjs.org/blog/layouts-rfc.
## Details
I'm going to document the differences with the current router here (will be reworked for the upgrade guide)
### Client-side cache
In the current router we have an in-memory cache for getStaticProps data so that if you prefetch and then navigate to a route that has been prefetched it'll be near-instant. For getServerSideProps the behavior is different, any navigation to a page with getServerSideProps fetches the data again.
In the new model the cache is a fundamental piece, it's more granular than at the page level and is set up to ensure consistency across concurrent renders. It can also be invalidated at any level.
#### Push/Replace (also applies to next/link)
The new router still has a `router.push` / `router.replace` method.
There are a few differences in how it works though:
- It only takes `href` as an argument, historically you had to provide `href` (the page path) and `as` (the actual url path) to do dynamic routing. In later versions of Next.js this is no longer required and in the majority of cases `as` was no longer needed. In the new router there's no way to reason about `href` vs `as` because there is no notion of "pages" in the browser.
- Both methods now use `startTransition`, you can wrap these in your own `startTransition` to get `isPending`
- The push/replace support concurrent rendering. When a render is bailed by clicking a different link to navigate to a completely different page that still works and doesn't cause race conditions.
- Support for optimistic loading states when navigating
##### Hard/Soft push/replace
Because of the client-side cache being reworked this now allows us to cover two cases: hard push and soft push.
The main difference between the two is if the cache is reused while navigating. The default for `next/link` is a `hard` push which means that the part of the cache affected by the navigation will be invalidated, e.g. if you already navigated to `/dashboard` and you `router.push('/dashboard')` again it'll get the latest version. This is similar to the existing `getServerSideProps` handling.
In case of a soft push (API to be defined but for testing added `router.softPush('/')`) it'll reuse the existing cache and not invalidate parts that are already filled in. In practice this means it's more like the `getStaticProps` client-side navigation because it does not fetch on navigation except if a part of the page is missing.
#### Back/Forward navigation
Back and Forward navigation ([popstate](https://developer.mozilla.org/en-US/docs/Web/API/Window/popstate_event)) are always handled as a soft navigation, meaning that the cache is reused, this ensures back/forward navigation is near-instant when it's in the client-side cache. This will also allow back/forward navigation to be a high priority update instead of a transition as it is based on user interaction. Note: in this PR it still uses `startTransition` as there's no way to handle the high priority update suspending which happens in case of missing data in the cache. We're working with the React team on a solution for this particular case.
### Layouts
Note: this section assumes you've read [The layouts RFC](https://nextjs.org/blog/layouts-rfc) and [React Server Components RFC](https://reactjs.org/blog/2020/12/21/data-fetching-with-react-server-components.html)
React Server Components rendering leverages the Flight streaming mechanism in React 18, this allows sending a serializable representation of the rendered React tree on the server to the browser, the client-side React can use this serialized representation to render components client-side without the JavaScript being sent to the browser. This is one of the building blocks of Server Components. This allows a bunch of interesting features but for now I'll keep it to how it affects layouts.
When you have a `app/dashboard/layout.js` and `app/dashboard/page.js` the page will render as children of the layout, when you add another page like `app/dashboard/integrations/page.js` that page falls under the dashboard layout as well. When client-side navigating the new router automatically figures out if the page you're navigating to can be a smaller render than the whole page, in this case `app/dashboard/page.js` and `app/dashboard/integrations/page.js` share the `app/dashboard/layout.js` so instead of rendering the whole page we render below the layout component, this means the layout itself does not get re-rendered, the layout's `getServerSideProps` would not be called, and the Flight response would only hold the result of `app/dashboard/integrations/page.js`, effectively giving you the smallest patch for the UI.
---
Note: the commits in this PR were mostly work in progress to ensure it wasn't lost along the way. The implementation was reworked a bunch of times to where it is now.
Co-authored-by: Jiachi Liu <4800338+huozhi@users.noreply.github.com>
Co-authored-by: JJ Kasper <22380829+ijjk@users.noreply.github.com>
trying to shorten the svg blur placeholder on `next/future/image`:
- is the `xlink` namespace needed?
- are self-closing tags allowed?
## 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)
Continue the work in #38310, this PR includes CSS files as chunks in the manifest for each client component, and then make sure the flight client loads the CSS files correctly.
## Bug
- [ ] Related issues linked using `fixes #number`
- [x] 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)
The `chunkFilenameMap` should take priority over the webpack built-in one here.
## Bug
- [ ] Related issues linked using `fixes #number`
- [x] 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)
This PR fixes the case when `next/future/image` is missing the width or height props.
It also fixes a case when `100%` or `100vh` were incorrectly parsed as `100` pixels.
