As discussed with @csswizardry. This is a temporary option in case you know the preloads are not needed. It will likely be a default once the ScriptLoader work from @janicklas-ralph has been proven in partner apps and landed.
```js
// pages/index.js
export const config = {
unstable_JsPreload: false
}
```
This ensures we detect domain specific locales and redirect them client-side. Tests have been added in the `i18n` suite to ensure the domain redirect is applied correctly during a client-side navigation
Fixes: https://github.com/vercel/next.js/issues/19174
Follow-up PR to https://github.com/vercel/next.js/pull/17370 when the path is not prefixed with a locale and the default locale is the detected locale it doesn't redirect to locale prefixed variant. If the default locale path is visited and the default locale is visited this also redirects to the root removing the un-necessary locale in the URL.
This also exposes the `defaultLocale` on the router since the RFC mentions `Setting a defaultLocale is required in every i18n library so it'd be useful for Next.js to provide it to the application.` although doesn't explicitly spec where we want to expose it. If we want to expose it differently this can be updated.
This adds the initial changes outlined in the [i18n routing RFC](https://github.com/vercel/next.js/discussions/17078). This currently treats the locale prefix on routes similar to how the basePath is treated in that the config doesn't require any changes to your pages directory and is automatically stripped/added based on the detected locale that should be used.
Currently redirecting occurs on the `/` route if a locale is detected regardless of if an optional catch-all route would match the `/` route or not we may want to investigate whether we want to disable this redirection automatically if an `/index.js` file isn't present at root of the pages directory.
TODO:
- [x] ensure locale detection/populating works in serverless mode correctly
- [x] add tests for locale handling in different modes, fallback/getStaticProps/getServerSideProps
To be continued in fall-up PRs
- [ ] add tests for revalidate, auto-export, basePath + i18n
- [ ] add mapping of domains with locales
- [ ] investigate detecting locale against non-index routes and populating the locale in a cookie
x-ref: https://github.com/vercel/next.js/issues/17110
Removes `next-head-count`, improving support for 3rd party libraries that insert or append new elements to `<head>`.
---
This is more or less what a solution with a `data-` attribute would look like, except that instead of directly searching for elements with that attribute, we serialize the elements expected in `<head>` and then find them/assume ownership of them during initialization (in a manner similar to React's reconciliation) based on their properties.
There are two main assumptions here:
1. Content is served with compression, so duplicate serialization of e.g. inline script or style tags doesn't have a meaningful impact. Storing a hash would be a potential optimization.
2. 3rd party libraries primarily only insert new, unique elements to head. Libraries trying to actively manage elements that overlap with those that Next.js claims ownership of will still be unsupported.
The reason for this roundabout approach is that I'd really like to avoid `data-` if possible, for maximum compatibility. Implicitly adding an attribute could be a breaking change for some class of tools or crawlers and makes it otherwise impossible to insert raw HTML into `<head>`. Adding an unexpected attribute is why the original `class="next-head"` approach was problematic in the first place!
That said, while I don't expect this to be more problematic than `next-head-count` (anything that would break in this new model also should have broken in the old model), if that does end up being the case, it might make sense to just bite the bullet.
Fixes#11012Closes#16707
---
cc @Timer @timneutkens
Replace `url.parse` and `url.resolve` logic with whatwg `URL`, Bring in a customized `format` function to handle the node url objects that can be passed to router methods. This eliminates the need for `url` (and thus `native-url`) in core. Looks like it shaves off about 2.5Kb, according to the `size-limits` integration tests.
Fixes: #13512
Defined and exported type for `metric` used in [reportWebVitals](https://nextjs.org/docs/advanced-features/measuring-performance)
```
export function reportWebVitals(metric) {
if (metric.label === 'custom') {
console.log(metric) // The metric object ({ id, name, startTime, value, label }) is logged to the console
}
}
```
One can now do
```
import { NextWebVitalsMetric } from 'next/app'
export function reportWebVitals(metric: NextWebVitalsMetric ) {
if (metric.label === 'custom') {
console.log(metric) // The metric object ({ id, name, startTime, value, label }) is logged to the console
}
}
```
* Fix type on NextApiHandler
The example [here](https://nextjs.org/docs/api-routes/api-middlewares) shows that `NextApiHandler` can be async, so the return type should be `void | Promise<void>`.
* Add TS integration tests for API
This allows a page to be fully static (no runtime JavaScript) on a per-page basis.
The initial implementation does not disable JS in development mode as we need to figure out a way to inject CSS from CSS imports / CSS modules without executing the component JS. This restriction is somewhat similar to https://www.gatsbyjs.org/packages/gatsby-plugin-no-javascript/. All things considered that plugin only has a usage of 600 downloads per week though, hence why I've made this option unstable/experimental initially as I'd like to see adoption patterns for it first.
Having a built-in way to do this makes sense however as the people that do want to adopt this pattern are overriding Next.js internals currently and that'll break between versions.
Related issue: #5054 - Not adding `fixes` right now as this implementation needs more work. If anyone wants to work on this feel free to reach out on https://twitter.com/timneutkens
* Add initial support for new env config file
* Fix serverless processEnv call when no env is provided
* Add missing await for test method
* Update env config to .env.json and add dotenv loading
* ncc dotenv package
* Update type
* Update with new discussed behavior removing .env.json
* Update hot-reloader createEntrypoints
* Make sure .env is loaded before next.config.js
* Add tests for all separate .env files
* Remove comments
* Add override tests
* Add test for overriding env vars based on local environment
* Add support for .env.test
* Apply suggestions from code review
Co-Authored-By: Joe Haddad <joe.haddad@zeit.co>
* Use chalk for env loaded message
* Remove constant as it’s not needed
* Update test
* Update errsh, taskr, and CNA template ignores
* Make sure to only consider undefined missing
* Remove old .env ignore
* Update to not populate process.env with loaded env
* Add experimental flag and add loading of global env values
Co-authored-by: Tim Neutkens <timneutkens@me.com>
Co-authored-by: Joe Haddad <joe.haddad@zeit.co>
* checkpoint: api impl
* Add support for tryGetPreviewData
* snapshot: server(less) support
* Add X-Prerender-Bypass-Mode header support
* Pass preview data to getStaticProps call
* add TODO
* setPreviewData
* 100k iterations
* Handle jwt error
* Write out preview values
* forgot file
* set preview props
* Send preview props
* add preview props
* Pass around more data
* update yarn lock
* Fail on Invalid Prerender Manifest
* Make Missing Prerender Manifest Fatal
* fix ts errors
* fix test
* Fix setting cookies + maxage
* Secure is not needed as we encrypt necessary data
* Set on domain root
* Set cookie max ages
* Render a fallback on-demand for non-dynamic pages
* Test preview mode
* remove old build
* remove snapshots
* Add serverless tests
* use afterAll
* Remove object assigns
* fix cookie spread
* add comment
* Add initial SSG fallback handling
* Remove extra changes and update fallback handling
* Remove extra timeout for testing
* Update SSG tests in dynamic-routing suite
* Add racing to decide between rendering fallback and data
* Update size-limit test
* Update comment
* Make sure to follow correct route change order
* Make comment more verbose for racing
* Revert getStaticData to only return Promise
* Make sure to update URL on fallback
* Add retrying for data, de-dupe initial fallback request, and merge fallback replace
* Update to add preload for fallback pages data
* Add test for data preload link
* Use pre-built fallback in production mode
* Remove preload link for fallback from _document
* Update to make sure fallback is rendered correctly for serverless
* Use smaller name as it's not shortened
* Remove export as it's not used and it'll be shortened
* Update size
Co-authored-by: Joe Haddad <timer150@gmail.com>
* Polyfilling fetch and object-assign
* Polyfilling corejs object-assign
* Adding object-assign in polyfills.js. IE11 does not support Object.assign
* Fixing failing test
* Updating object.assign polyfill to fix aliasing
* Updating test case value to match new build stats
* Increasing the size of default build to 225kb
* Fixing defer-script test case to not include polyfill.js
* Revert README.md
* Re-design the polyfill approach based on PR feedback
* Adding comment and fixing test case
* Rename polyfills chunk
* Extract aliases into helper
* Remove extra new line
* Fix TypeScript typings
* Adding _internal_fetch alias
* Adjust build manifest plugin
* Build manifest plugin changes - adding a separate entry for polyfills
* Rename polyfills entry in build-manifest.json
* Remove old comment
* Fix TS
* Set key
* Polyfills already added
* Filtring polyfill.module.js
* Fix test
* Add __internal_fetch to alias rule
* Adjust name
* bump size
* ignore polyfills
* sigh