Use `Writable` instead of `Observable` and remove the `zen-observable` dependencies. I initially opted to use `Observable` for simplicity and fast iteration, but we should really just use `Writable` directly (or some other stream in the future).
React's streaming SSR has some [specific requirements](https://github.com/reactwg/react-18/discussions/66#discussioncomment-944266) on the stream API. Rather than trying to also squeeze a `Readable` in here, which might be more standard for node apps, I've just followed React's lead. By limiting ourselves to just `Writable`, it ought to be easier to adopt a different stream type in the future if desired.
The React `pipeToNodeWritable` API requires us to pass a stream immediately, but we don't actually have a `ServerResponse` to give it until `RenderResult.pipe(...)` is called later. For that reason, we pass React a `Writable` that we will simply forward to `res` later. This mechanism of deferring is `NodeWritablePiper`, which is just a function that can be called with `ServerResponse` (or another `Writable`, as we now do to render to string for static results) to have content written to it. `NodeWritablePiper` takes a `next` argument so that we can chain both synchronous and asynchronous pipers together.
Also does some clean up and adds another streaming test for backpressure.
Updates the React 18 concurrent tests to support streaming, by using webdriver (instead of cheerio) to support dynamic updates, and being more explicit about SSR vs. hydrated content.
Also enables streaming support by setting `supportsDynamicHTML: true` in `pipe(...)` for non-bot user agents.
## Documentation / Examples
- [x] Make sure the linting passes
- [x] Errors have helpful link attached, see `contributing.md` (for #28165, #27611)
- [x] Update test case
Do not fallback to loadable component when `reactRoot` is enabled but without `concurrentFeatures`. Thus we can enable pure client suspense:
`fallback` is always rendered on server side, but client side can work with fully functional suspense.
Closes#28117
### Changes
#### Feature
* Adopt `React.lazy` into `next/dynamic`, enable it when `options.suspense` is `true`
* Support `next/dynamic` with `suspense=true` in SSR and SSG
#### Tests
| Scenario | Case | Behavior |
|:----:|:----:|:----:|
| basics | react 17 or 18 by default | dev/build error or pass |
| blocking rendering | `reactRoot: true` + `concurrentFeatures: false` | dev/build pass |
| concurrent rendering | `reactRoot: true` + `concurrentFeatures: true` | dev/build pass |
## 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
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have helpful link attached, see `contributing.md`
For test only, previously the react-dom is still been resolved as react 17
## 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
* fix: react 18 new hydration API
* support react 18
* compat latest react only, fix resolved version
* fix tests
* Some changes based on https://github.com/reactwg/react-18/discussions/5
* fix test
Co-authored-by: Tim Neutkens <timneutkens@me.com>
Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>
Also logs a message when defaulting, and a warning when using a prerelease build of `react-dom` (e.g. the React 18 alpha) which are not officially supported.
Note: I've done this in `webpack-config.ts` instead of the Next.js config, as we don't actually want you to be able to opt-out *without* downgrading back to React 17, and so it ought to be entirely removed from the config eventually.