## 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`
* Add experimental config for middleware
* Apply suggestions from code review
Co-authored-by: Steven <steven@ceriously.com>
Co-authored-by: Steven <steven@ceriously.com>
## 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 `yarn lint`
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
As a follow up to #30041 which changed `<div>` to `<span>`, this PR makes sure that unexpected styles are not applied to the image wrapper or sizer spans.
For example: `.content span {}` would apply to all spans and incorrectly style the image wrapper.
This PR adds [`all: initial`](https://developer.mozilla.org/en-US/docs/Web/CSS/all) to effectively reset the span styles.
This replaces the server-sent events HMR connection with a WebSocket connection to prevent hitting browser connection limits, allow sending events back from the browser, and overall better performance.
This approach sets up the the `upgrade` event listener on the server immediately when created via `next dev` and on the first request using `req.socket.server` when created via a custom server. In a follow-up PR we can push the files changed via the WebSocket as well.
x-ref: https://github.com/vercel/next.js/issues/10061
x-ref: https://github.com/vercel/next.js/issues/8064
x-ref: https://github.com/vercel/next.js/issues/4495
## 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
In some cases, e. g. when introducing a build error and then returning to the successful build again, the build error modal stays open. That shouldn't happen
### Experimental
Introduce `next/vitals` and `useExperimentalWebVitalsReport` API which is not limited by `_app`.
`pages/index.js`
```jsx
import { useExperimentalWebVitalsReport } from 'next/vitals'
export default function Index() {
useExperimentalWebVitalsReport((metric) => {
// handle metric...
})
return 'sup'
}
```
See https://github.com/w3c/csswg-drafts/issues/6501 to see how I found this.
This line doesn't recompute layout in browsers, because `"height"` is given as a pseudo-element name rather than a property.
The right way to do what it wants is `getComputedStyle(document.body).height`, but given nobody noticed this (and this is generally never needed, manually triggering layout should never be needed to avoid FOUC) it seems better to keep current behavior and just remove the call.
This PR proposes a fix for https://github.com/vercel/next.js/issues/11107 (JS modules are loaded twice). A more detailed explanation of the investigation that led to this PR can be found in the issue's comments (https://github.com/vercel/next.js/issues/11107#issuecomment-791780168).
## Replicability
To identify that the issue replicates on any given project, you need to
1. look at the network tab (first/clean load of site, so preferably ⌘+⇧+R on an incognito tab),
2. sort by "name", and filter requests by `mime-type:application/javascript` (selecting "JS" in the devtools filters will actually show all "script" types, but ignore all "javascript" types)
3. look for pairs of identical calls with one originating from initial HTML (`preload` of priority "high" originating from "(index)" or "([page name])") and another one from a script (`prefetch` of priority "lowest" originating from a .js file), where neither of the files is served from the cache.
Here's a screenshot of an example of what to look for:
<img width="601" alt="Screen Shot 2021-03-07 at 09 59 18" src="https://user-images.githubusercontent.com/1325721/110234627-cf1c6d00-7f2b-11eb-9cd7-749bf881ba56.png">
The issue was reproduced easily on the following projects:
- On [nextjs.org](https://nextjs.org/) where duplicates add up to ~70kB of transferred javascript out of 470kB (14.9%).
- On [vercel.com](https://vercel.com/) where duplicates add up to ~105kB of transferred javascript out of 557kB (18.8%).
- On [tiktok.com](https://tiktok.com/en) where duplicates add up to ~514kB of transferred javascript out of 1556kB (33%).
- In my own project using `"next": "^10.0.1"` (private repo) where duplicates add up to about 5% of total transferred javascript.
- In the issue's comments, a developer reported a replication using `"^10.0.7"` on a [public repo](https://github.com/SidOfc/sidneyliebrand.io).
## Some information about the fix
- Both `preload` and `prefetch` values for `<link rel="x">` behave similarly, with the difference being in network priority level (preload is high priority, prefetch is lowest priority).
- Next.js uses `<link rel="preload">` in its initial HTML but then *only* uses `<link rel="prefetch">` for the rest of the lifetime of the page.
- However, when Next.js detects that a script should be requested in advance, it only checks for matching `<link rel="prefetch">` and not `<link rel="preload">` (which have higher priority and are present earlier in the DOM, thus have a greater likelihood of being already loaded).
This PR aims to fix that oversight.
## Potential issues (none AFAIK)
As far as I can tell by looking through the codebase, **there is no downside** not to add a `prefetch` when a `preload` is already in the DOM. No other script looks for a `<link>` based on its `rel` attribute.
* Remove inert font tag in font optimization
* Fix lint
* Remove inert font tag during font optimization
* Fix lint
* Fix lint
* Fix lint
Co-authored-by: JJ Kasper <jj@jjsweb.site>
This applies the fix from the awesome investigation done in https://github.com/vercel/next.js/issues/28797 by @jayphelps and adds a test to ensure this is working as expected. It seems that the `route-loader` has a race condition while prefetching and if a script is executed before we have created a current "future" entry to resolve the entry stays in a pending state causing routes to hang so this handles the condition by ensuring pending/errored entries do not stay around.
## Bug
- [x] Related issues linked using `fixes #number`
- [x] Integration tests added
- [x] Errors have helpful link attached, see `contributing.md`
Fixes: https://github.com/vercel/next.js/issues/28797
Fixes: https://github.com/vercel/next.js/issues/27783
This type was added in PR #28269 but doesn't need to be public and was causing conflicts with `@types/react@17`.
We currently use `@types/react@16` so ideally we should upgrade to `@types/react@17` and then remove the `ts-ignore`.
Fixes#28647
This PR does a few things:
- Moves `<noscript>` usage below the blur image since so that the `<noscript>` image renders on top of the blur image
- Remove the `isVisible` check for `<noscript>` since we can't rely on client-side JS
- Add `loading=lazy` to the `<noscript>` image to take advantage of native lazy loading (can't rely on JS lazy loading)
Fixes#28251
Removes the extra webpack handling that was previously done, this ensures the file which is already minified and compiled does not get passed through minification again.
Largely based on #21418Closes#21418
The polyfill loading already has tests so no other changes are necessary.
## 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
This PR resurrects #23622 which has not been updated in a while. Makes the `Image` component handle `blob:` object urls.
closes#23622fixes#19291
credits: @sdn90
## 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
This PR adds a single data attribute to the image element generated by the image component `data-nimg`) which just serves to signal that this image element is from the component. Currently it's hard to quickly/programmatically determine with certainty whether an image is from the component or not, so this change should make it easier for us to diagnose and improve performance issues related to the image component.
Replaces Babel with SWC for Next.js core client-side files.
## 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
We've never supported the `style` prop as seen in the docs https://nextjs.org/docs/api-reference/next/image#other-props
TS users already get a build error but JS users were left in the dark.
This PR adds a warning so its clear during `next dev`.
The fix in PR #25749 only works some of the time. The reason why it
doesn't work all of the time is because the `devBuildResolve` function
is called when the assets have been built, but this can happen before
the `getFilesForRoute` promise chain has completed, and thus the
`cancelled` variable could not yet have been updated.
To fix this we wait for the `getFilesForRoute` promise chain to be
fulfilled and then resolve the `devBuildPromise` promise afterwards.
This allows the `getFilesForRoute` promise chain to be fulfilled before
and the `cancelled` variable can be updated accordingly.
If an error is thrown somewhere in the `getFilesForRoute` promise chain,
i.e. due to a failed fetch request, then that will also resolve the
`devBuildPromise` and the error will bubble up to ultimately become a
`routeChangeError` which will reload the page.
With this fix the need to listen for HMR events has become obsolete as
regardless of when the HMR build/sync events complete we still want to
ensure that the `getFilesForRoute` promise chain has been fulfilled
before resolving the `devBuildPromise`.
Co-authored-by: Tobias Järvelöv <tobias.jarvelov@oderland.se>
Co-authored-by: JJ Kasper <jj@jjsweb.site>
This PR adds `lazyBoundary` prop on Image Component.
This feature is to load the images earlier.
I'm not good at English. So, I couldn't explain enough in the documentation what `lazyBoundary` is.
Feature request: https://github.com/vercel/next.js/discussions/24552
## 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.
- [ ] Errors have helpful link attached, see `contributing.md`
## Documentation / Examples
- [x] Make sure the linting passes
