fixes some bugs and improves performance
## Bug
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
## 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.
## Documentation / Examples
- [ ] Make sure the linting passes
This is a follow-up PR of #19052, where `visibility: inherit` was mistakenly added back. It was removed in #23278.
## Bug
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
## 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.
## Documentation / Examples
- [ ] Make sure the linting passes
For #22228
This PR:
- Adds ESLint to toolchain
- Included by default for builds (`next build`)
- Can be enabled for development (`next dev`)
- Custom formatter built for output
- Adds appropriate tests
- Adds two documentation pages
Brings back the remaining Node.js module polyfills to not break existing apps upgrading from webpack 4 to webpack 5.
Fixes#23169
## Bug
- [x] Related issues linked using `fixes #number`
- [x] Integration tests added
## 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.
## Documentation / Examples
- [ ] Make sure the linting passes
The current `<Image />` component does not fallback gracefully when JavaScript is disabled in the client / browser.
You can test this with the [official Next/Image example](https://csb-4k0kr-p8ya8f304.vercel.app/), by disabling JavaScript in the browser's DevTools. Video demo: https://streamable.com/frkvw9
This PR aims to fix this behaviour by using `<noscript></noscript>` tags to conditionally display a standard `<img>` element using the `props` passed to `<Image />` when JavaScript is disabled.
For browser sessions where JavaScript is enabled, this will not cause an increase in network requests, so there should be no downside.
One area where this PR is a bit "hacky" is that it uses a negative `margin-top` to counteract `sizerStyle.paddingTop`. From what I can tell, `sizerStyle.paddingTop` is generated on the server side, where we can not know ahead of time whether JavaScript is enabled in the browser - hence why I've opted for this solution.
Fixes#19223Fixes#21214
This PR removes the `visibility` style property change from next/image. It was previously added in #18195 to fix a bug that when no `src` is set, and that bug is not valid anymore as all images will always have `src` (and a fallback too).
It also fixes the problem that screen readers ignore elements with `visibility: hidden`.
Fixes#23201.
## Bug
- [x] Related issues #23201
- [ ] Integration tests added
## 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.
## Documentation / Examples
- [ ] Make sure the linting passes
fixes#23125
fixes https://github.com/tailwindlabs/tailwindcss-jit/issues/54
## Bug
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
## 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.
## Documentation / Examples
- [ ] Make sure the linting passes
## Bug
- [x] Related issues linked using `fixes #number`
- [ ] Integration tests added
## 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.
## Documentation / Examples
- [ ] Make sure the linting passes
Fixes#23240
This PR attempts to provide an option to allow importing TS/TSX from outside of the current Next.js project root directory. Although this goes against the design decision that no source code should be imported from outside of root and [might bring tons of issues](https://github.com/vercel/next.js/issues/19928#issuecomment-741596557), it will still be helpful in some monorepo use cases.
This PR assumes that the external files are following the same language syntax rules and under the same tooling versions as the source code inside your project root. And it's also not allowed to enable the `baseUrl` feature in the external directory (as the project should only have 1 import base URL).
X-ref: #9474, #15569, #19928, #20374.
This ensures we exit the build process after the build completes even if timers/connections are left open since this can cause the process to hang indefinitely. This was the previous behavior although got changed un-intentionally in e27b7e996d
This updates our production test with an open timer to ensure it doesn't block the process from completing.
As stated in #23157, this PR merges all the operations into 1 worker thread (`processBuffer` in `impl.ts`) and only pass a list of operation names and args into the worker. This should improve the speed and memory usage of next/image.
Fixes#23157. X-ref: #22925.
This allows to use `__NEXT_WEBPACK_LOGGING` to enable verbose webpack logging output to investigate into performance and cache problems.
`__NEXT_WEBPACK_LOGGING=1` enables some basic logging
`__NEXT_WEBPACK_LOGGING=infrastructure` enables only infrastructure logging
`__NEXT_WEBPACK_LOGGING=profile-client` enables deep profile output of the client build
`__NEXT_WEBPACK_LOGGING=profile-server` same for the server
`__NEXT_WEBPACK_LOGGING=profile-client,infrastructure` combines multiple things
* this will fix problems with serverless target which doesn't use a runtime chunk
* It also omit env vars from contributing to cache version as webpack will handle that now
* It moves the webpack-runtime chunk from ./chunks back to ./
This PR upgrades `jest-worker` and `jest-cli` to the latest pre-release version, also removed `jest-circus` which is included in Jest by default. `jest-worker@next` includes a fix for memory leak that we need (https://github.com/facebook/jest/pull/11187).
Fixes#22925. This will also improve the OOM issue for `next dev` #15855.
# Route Announcements
## Summary
This PR improves the accessibility of NextJS's client-side navigation by announcing route changes to screen readers.
## Context
When a user who is sighted clicks on a link, they can see the content change. It's an affirmation that what the user intended to do by clicking a link actually worked! Users navigating the page via a screen-reader will not get this feedback on NextJS sites (This is an issue on many SPA-like architectures).
https://user-images.githubusercontent.com/4213649/103017382-63b02b00-44f8-11eb-9940-fb530d2d3018.mov
## Solution
Whenever there is a route change, the new `<RouteAnnouncer />` will look for a name to give the new page and then announce it! The name is found by first looking for an `h1`, falling back to `document.title`, and lastly to `pathname`. `<RouteAnnouncer />` is a visually hidden component placed within the `<AppContainer />`.
## Demo
https://user-images.githubusercontent.com/4213649/103017401-6ad73900-44f8-11eb-8050-b3e9a7e0c3f2.mov
## Inspiration
First and foremost, this PR was inspired by @marcysutton's studies and writing, [What we learned from user testing of accessible client-side routing techniques with Fable Tech Labs
](https://www.gatsbyjs.com/blog/2019-07-11-user-testing-accessible-client-routing/) as well as @madalynrose's [Accessible Routing](https://github.com/gatsbyjs/gatsby/pull/19290) PR for Gatsby.
There were also learnings gleaned from the conversations within #7681.
### Related Issues & PRs
- Resolves#7681
- Relates to #19963
This makes sure we don't trigger the export step if we aren't exporting any static pages during a build. This also adds an invariant to ensure we don't attempt creating a progress with 0 items.
Fixes: https://github.com/vercel/next.js/issues/22994
A number of changes here. I recommend viewing the diff with the <a href="?w=1">whitespace flag enabled</a>.
- OpenTelemetry is replaced with a custom and lightweight tracing solution.
- Three trace targets are currently supported: console, Zipkin, and NextJS.
- Tracing is now governed by environment variables rather than `--require instrument.js`.
+ `TRACE_TARGET`: one of `CONSOLE`, `ZIPKIN`, or `TELEMETRY`; defaults to `TELEMETRY` if unset or invalid.
+ `TRACE_ID`: an 8-byte hex-encoded value used as the Zipkin trace ID; if not provided, this value will be randomly generated and passed down to subprocesses.
Other sundry:
- I'm missing something, probably a setup step, with the Zipkin target. Traces are captured successfully, but you have to manually enter the Trace ID in order to view the trace - it doesn't show up in queries.
- I'm generally unhappy with [this commit](235cedcb3e). It is... untidy to provide a telemetry object via `setGlobal`, but I don't have a ready alternative. Is `distDir` strictly required when creating a new Telemetry object? I didn't dig too deep here.
As noted, there are a lot of changes, so it'd be great if a reviewer could:
- [ ] pull down the branch and try to break it
- [ ] check the Zipkin traces and identify possible regressions in the functionality
Closes#22570Fixes#22574
Currently if you have `sizes` set in `next/image`, the image will likely be downloaded multiple times (usually twice) on Safari (macOS and iOS): the correct size for the viewport, and the original size specified in `src`.
Also make sure you have "Ignore Resource Cache" disabled in the Safari Devtools when trying to reproduce:
![CleanShot 2021-03-09 at 21 05 54@2x](https://user-images.githubusercontent.com/3676859/110476820-6399f180-811d-11eb-93ec-5b2482c87884.png)
The root cause is the way Safari handles `<img>`'s attribute updates. Although React updates all the attributes one by one synchronously and programmatically, Safari will still try to fetch the resource immediately and won't wait for other DOM changes to be finished.
That means if we set the following 3 attributes in this order: `src`, `srcSet`, `sizes`. Safari will fetch the image when `src` is set. And then once `srcSet` is there it will fetch the resource again based on it. And finally, when `sizes` is updated it might correct the resource URL again.
So the fix here is simple: by just reordering those to `sizes`, `srcSet`, `src`, it will only load the image with the correct size only once:
<img width="1498" alt="CleanShot 2021-03-09 at 21 05 30@2x" src="https://user-images.githubusercontent.com/3676859/110477852-a27c7700-811e-11eb-88dc-d6e7895f67bd.png">
Fixes#19478.
This updates to not automatically export `/500` from `_error` if a custom `getInitialProps` is used since logic may be used inside of this method that causes the export to fail. Users can still opt-in to the static `/500` by adding a `pages/500.js` file.
This also refactors checking `_app` for custom `getInitialProps` to outside of the static check loop to prevent a potential race condition where we could run this check multiple times un-necessarily.
Fixes: https://github.com/vercel/next.js/issues/22815
This ensures we load all env values before loading `next.config.js` since these values can be used in there. This also updates to ensure we're testing these values are available while loading `next.config.js` so we don't regress on this.
Fixes: https://github.com/vercel/next.js/issues/22811