- Enable newNextLinkBehavior. See #36436
- Run next/link codemod on test suite
Note that from when this lands on apps trying canary will need to run
the new-link codemod in order to upgrade.
Ideally we have to detect `<a>` while rendering the new link and warn
for it.
Co-authored-by: Steven <steven@ceriously.com>
This PR introduces breaking changes by renaming components.
- Rename `next/image` to `next/legacy/image`
- Rename `next/future/image` to `next/image`
The diff is very confusing because both components are very similar so git got confused.
## Feature
Change server components convention from using `.server.js` / `.client.js` file extension to determine it's a server or client component to using `'client'` js literal as a directive for determine client components boundary.
React RFC: https://github.com/reactjs/rfcs/pull/189
New behavior doesn't consume `.server.js` as server components any more, if you're enabling `serverComponents` flag, every `page.js` in app dir will become server components by default. If you adding a `'client'` directive to the page, then that page will become a client component. This rule also applies to the normal js components, client components will require a `'client'` directive to indicate its identity, instead of having a `.client.js` extension.
- [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
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have helpful link attached, see `contributing.md`
Co-authored-by: Shu Ding <3676859+shuding@users.noreply.github.com>
Follow-up to #37551
Implements prefetching for the new router.
There are multiple behaviors related to prefetching so I've split them out for each case. The list below each case is what's prefetched:
Reference:
- Checkmark checked → it's implemented.
- RSC Payload → Rendered server components.
- Router state → Patch for the router history state.
- Preloads for client component entry → This will be handled in a follow-up PR.
- No `loading.js` static case → Will be handled in a follow-up PR.
---
- `prefetch={true}` (default, same as current router, links in viewport are prefetched)
- [x] Static all the way down the component tree
- [x] RSC payload
- [x] Router state
- [ ] preloads for the client component entry
- [x] Not static all the way down the component tree
- [x] With `loading.js`
- [x] RSC payload up until the loading below the common layout
- [x] router state
- [ ] preloads for the client component entry
- [x] No `loading.js` (This case can be static files to make sure it’s fast)
- [x] router state
- [ ] preloads for the client component entry
- `prefetch={false}`
- [x] always do an optimistic navigation. We already have this implemented where it tries to figure out the router state based on the provided url. That result might be wrong but the router will automatically figure out that
---
In the first implementation there is a distinction between `hard` and `soft` navigation. With the addition of prefetching you no longer have to add a `soft` prop to `next/link` in order to leverage the `soft` case.
A heuristic has been added that automatically prefers `soft` navigation except when navigating between mismatching dynamic parameters.
An example:
- `app/[userOrTeam]/dashboard/page.js` and `app/[userOrTeam]/dashboard/settings/page.js`
- `/tim/dashboard` → `/tim/dashboard/settings` = Soft navigation
- `/tim/dashboard` → `/vercel/dashboard` = Hard navigation
- `/vercel/dashboard` → `/vercel/dashboard/settings` = Soft navigation
- `/vercel/dashboard/settings` -> `/tim/dashboard` = Hard navigation
---
While adding these new heuristics some of the tests started failing and I found some state bugs in `router.reload()` which have been fixed. An example being when you push to `/dashboard` while on `/` in the same transition it would navigate to `/`, it also wouldn't push a new history entry. Both of these cases are now fixed:
```
React.startTransition(() => {
router.push('/dashboard')
router.reload()
})
```
---
While debugging the various changes I ended up debugging and manually diffing the cache and router state quite often and was looking at a way to automate this. `useReducer` is quite similar to Redux so I was wondering if Redux Devtools could be used in order to debug the various actions as it has diffing built-in. It took a bit of time to figure out the connection mechanism but in the end I figured out how to connect `useReducer`, a new hook `useReducerWithReduxDevtools` has been added, we'll probably want to put this behind a compile-time flag when the new router is marked stable but until then it's useful to have it enabled by default (only when you have Redux Devtools installed ofcourse).
> ⚠️ Redux Devtools is only connected to take incoming actions / state. Time travel and other features are not supported because the state sent to the devtools is normalized to allow diffing the maps, you can't move backward based on that state so applying the state is not connected.
Example of the integration:
<img width="1912" alt="Screen Shot 2022-09-02 at 10 00 40" src="https://user-images.githubusercontent.com/6324199/188637303-ad8d6a81-15e5-4b65-875b-1c4f93df4e44.png">
Starting in Node.js 18, the `fetch` global was made available and that caused the squoosh implementation to assume it was on a web browser and try to fetch the wasm file instead of reading it from the filesystem. This PR deletes the code trying to fetch since we know that squoosh only runs in the Image Optimization API, not the browser.
- Fixes#38020
- Enables a test that was disabled in #38460
