This is the first of a series of PRs, that let you pass functions, by
reference, to the client and back. E.g. through Server Context. It's
like client references but they're opaque on the client and resolved on
the server.
To do this, for security, you must opt-in to exposing these functions to
the client using the `"use server"` directive. The `"use client"`
directive lets you enter the client from the server. The `"use server"`
directive lets you enter the server from the client.
This works by tagging those functions as Server References. We could
potentially expand this to other non-serializable or stateful objects
too like classes.
This only implements server->server CJS imports and server->server ESM
imports. We really should add a loader to the webpack plug-in for
client->server imports too. I'll leave closures as an exercise for
integrators.
You can't "call" a client reference on the server, however, you can
"call" a server reference on the client. This invokes a callback on the
Flight client options called `callServer`. This lets a router implement
calling back to the server. Effectively creating an RPC. This is using
JSON for serializing those arguments but more utils coming from
client->server serialization.
We currently abuse the browser builds for Web streams derived
environments. We already have a special build for Bun but we should also
have one for [other "edge"
runtimes](https://runtime-keys.proposal.wintercg.org/) so that we can
maximally take advantage of the APIs that exist on each platform.
In practice, we currently check for a global property called
`AsyncLocalStorage` in the server browser builds which we shouldn't
really do since browsers likely won't ever have it. Additionally, this
should probably move to an import which we can't add to actual browser
builds where that will be an invalid import. So it has to be a separate
build. That's not done yet in this PR but Vercel will follow
Cloudflare's lead here.
The `deno` key still points to the browser build since there's no
AsyncLocalStorage there but it could use this same or a custom build if
support is added.
This updates the Flight fixture to support the new ESM loaders in newer
versions of Node.js.
It also uses native fetch since react-fetch is gone now. (This part
requires Node 18 to run the fixture.)
I also updated everything to use the `"use client"` convention instead
of file name based convention.
The biggest hack here is that the Webpack plugin now just writes every
`.js` file in the manifest. This needs to be more scoped. In practice,
this new convention effectively requires you to traverse the server
graph first to find the actual used files. This is enough to at least
run our own fixture though.
I didn't update the "blocks" fixture.
More details in each commit message.
The old version of prettier we were using didn't support the Flow syntax
to access properties in a type using `SomeType['prop']`. This updates
`prettier` and `rollup-plugin-prettier` to the latest versions.
I added the prettier config `arrowParens: "avoid"` to reduce the diff
size as the default has changed in Prettier 2.0. The largest amount of
changes comes from function expressions now having a space. This doesn't
have an option to preserve the old behavior, so we have to update this.
This shim is no longer needed on www, in fact I had already deleted it
there and it's currently not on www. See D42503692 which is trying to
add it back as I didn't realize this file was synced from GitHub.
~~[Fizz] Duplicate completeBoundaryWithStyles to not reference globals~~
## Summary
Follow-up / cleanup PR to #25437
- `completeBoundaryWithStylesInlineLocals` is used by the Fizz external
runtime, which bundles together all Fizz instruction functions (and is
able to reference / rename `completeBoundary` and `resourceMap` as
locals).
- `completeBoundaryWithStylesInlineGlobals` is used by the Fizz inline
script writer, which sends Fizz instruction functions on an as-needed
basis. This version needs to reference `completeBoundary($RC)` and
`resourceMap($RM)` as globals.
Ideally, Closure would take care of inlining a shared implementation,
but I couldn't figure out a zero-overhead inline due to lack of an
`@inline` compiler directive. It seems that Closure thinks that a shared
`completeBoundaryWithStyles` is too large and will always keep it as a
separate function. I've also tried currying / writing a higher order
function (`getCompleteBoundaryWithStyles`) with no luck
## How did you test this change?
- generated Fizz inline instructions should be unchanged
- bundle size for unstable_external_runtime should be slightly smaller
(due to lack of globals)
- `ReactDOMFizzServer-test.js` and `ReactDOMFloat-test.js` should be
unaffected
## Summary
Updating import for babel-code-frame to use the official @babel package,
as babel-code-frame is a ghost dependency. This change is necessary to
avoid potential issues and stay up-to-date with the latest version of
@babel/code-frame, which is already declared in our project's
package.json.
## How did you test this change?
yarn test
Flow introduced a new syntax to annotated the context type of a
function, this tries to update the rest and add 1 example usage.
- 2b1fb91a55 already added the changes
required for eslint.
- Jest transform is updated to use the recommended `hermes-parser` which
can parse current and Flow syntax and will be updated in the future.
- Rollup uses a new plugin to strip the flow types. This isn't ideal as
the npm module is deprecated in favor of using `hermes-parser`, but I
couldn't figure out how to integrate that with Rollup.
Hermes parser is the preferred parser for Flow code going forward. We
need to upgrade to this parser to support new Flow syntax like function
`this` context type annotations or `ObjectType['prop']` syntax.
Unfortunately, there's quite a few upgrades here to make it work somehow
(dependencies between the changes)
- ~Upgrade `eslint` to `8.*`~ reverted this as the React eslint plugin
tests depend on the older version and there's a [yarn
bug](https://github.com/yarnpkg/yarn/issues/6285) that prevents
`devDependencies` and `peerDependencies` to different versions.
- Remove `eslint-config-fbjs` preset dependency and inline the rules,
imho this makes it a lot clearer what the rules are.
- Remove the turned off `jsx-a11y/*` rules and it's dependency instead
of inlining those from the `fbjs` config.
- Update parser and dependency from `babel-eslint` to `hermes-eslint`.
- `ft-flow/no-unused-expressions` rule replaces `no-unused-expressions`
which now allows standalone type asserts, e.g. `(foo: number);`
- Bunch of globals added to the eslint config
- Disabled `no-redeclare`, seems like the eslint upgrade started making
this more precise and warn against re-defined globals like
`__EXPERIMENTAL__` (in rollup scripts) or `fetch` (when importing fetch
from node-fetch).
- Minor lint fixes like duplicate keys in objects.
This isn't the right way to do this, but internally we have some
restrictions so we need to add an indirection. Let's land this now so we
can catch up our sync and then fix forward from there.
Co-authored-by: Jan Kassens <jkassens@meta.com>
We've heard from multiple contributors that the Reconciler forking
mechanism was confusing and/or annoying to deal with. Since it's
currently unused and there's no immediate plans to start using it again,
this removes the forking.
Fully removing the fork is split into 2 steps to preserve file history:
**This PR**
- remove `enableNewReconciler` feature flag.
- remove `unstable_isNewReconciler` export
- remove eslint rules for cross fork imports
- remove `*.new.js` files and update imports
- merge non-suffixed files into `*.old` files where both exist
(sometimes types were defined there)
**#25775**
- rename `*.old` files
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Following
[comment](https://github.com/facebook/react/pull/25437#discussion_r1010944983)
in #25437 , the external runtime implementation should be moved from
`react-dom` to `react-dom-bindings`.
I did have a question here:
I set the entrypoint to `react-dom/unstable_server-external-runtime.js`,
since a.) I was following #25436 as an example and b.)
`react-dom-bindings` was missing a `README.md` and `npm/`. This also
involved adding the external runtime to `package.json`.
However, the external runtime isn't really a `react-dom` entrypoint. Is
this change alright, or should I change the bundling code instead?
## How did you test this change?
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This extends the scope of the cache and fetch instrumentation using
AsyncLocalStorage for microtasks. This is an intermediate step. It sets
up the dispatcher only once. This is unique to RSC because it uses the
react.shared-subset module for its shared state.
Ideally we should support multiple renderers. We should also have this
take over from an outer SSR's instrumented fetch. We should also be able
to have a fallback to global state per request where AsyncLocalStorage
doesn't exist and then the whole client-side solutions. I'm still
figuring out the right wiring for that so this is a temporary hack.
* Facebook -> Meta in copyright
rg --files | xargs sed -i 's#Copyright (c) Facebook, Inc. and its affiliates.#Copyright (c) Meta Platforms, Inc. and affiliates.#g'
* Manual tweaks
* float enhance!!!
Support preinit as script
Support resources from async scripts
Support saving the precedence place when rendering the shell
There was a significant change to the flushing order of resources which follows the general principal of...
1. stuff that blocks display
2. stuff that we know will be used
3. stuff that was explicitly preloaded
As a consequence if you preinit a style now it won't automatically flush in the shell unless you actually depend on it in your tree. To avoid races with precedence order we now emit a tag that saves the place amongst the precedence hierarchy so late insertions still end up where they were intended
There is also a novel hydration pathway for certain tags. If you render an async script with an onLoad or onError it will always treat it like an insertion rather than a hydration.
* restore preinit style flushing behavior and nits
* Scaffolding for react-dom/unstable_external-server-runtime
Implements a new bundle type for in our build config called
BROWSER_SCRIPT. This is intended for scripts that get delivered straight
to the browser without needing to be processed by a bundler. (And also
doesn't include any extra UMD crap.)
Right now there's only a single use case so I didn't stress about making
it general purpose.
The use case is: a script that loads the Fizz browser runtime, and sets
up a MutationObserver to receive instructions as HTML streams in. This
will be an alternative option to the default Fizz behavior of sending
the runtime down as inline script tags, to accommodate environments
where inline script tags are not allowed.
There's no development version of this bundle because it doesn't contain
any warnings or run any user code.
None of the actual implementation is in this PR; it just sets up the
build infra.
Co-authored-by: Mofei Zhang <feifei0@fb.com>
* Set BUNDLE_SCRIPT's GCC output format to ES5
This removes the automatic 'use strict' directive, which we don't need.
Co-authored-by: Mofei Zhang <feifei0@fb.com>
* Move Fizz inline instructions to unified module
Instead of a separate module per instruction, this exports all of them
from a unified module.
In the next step, I'll add a script to generate this new module.
* Add script to generate inline Fizz runtime
This adds a script to generate the inline Fizz runtime. Previously, the
runtime source was in an inline comment, and a compiled version of the
instructions were hardcoded as strings into the Fizz implementation,
where they are injected into the HTML stream.
I've moved the source for the instructions to a regular JavaScript
module. A script compiles the instructions with Closure, then generates
another module that exports the compiled instructions as strings.
Then the Fizz runtime imports the instructions from the
generated module.
To build the instructions, run:
yarn generate-inline-fizz-runtime
In the next step, I'll add a CI check to verify that the generated files
are up to date.
* Check in CI if generated Fizz runtime is in sync
The generated Fizz runtime is checked into source. In CI, we'll ensure
it stays in sync by running the script and confirming nothing changed.
* Missing Hooks
* Remove www forks. These can use __SECRET... instead.
* Move cache to separate dispatcher
These will be available in more contexts than just render.
Publish an aliasable entry for `react-dom` top level package exports for use in server environments. This is a stub containing only the exports that we expect to retain in the top level once 19 is released
* [Fizz/Float] Float for stylesheet resources
This commit implements Float in Fizz and on the Client. The initial set of supported APIs is roughly
1. Convert certain stylesheets into style Resources when opting in with precedence prop
2. Emit preloads for stylesheets and explicit preload tags
3. Dedupe all Resources by href
4. Implement ReactDOM.preload() to allow for imperative preloading
5. Implement ReactDOM.preinit() to allow for imperative preinitialization
Currently supports
1. style Resources (link rel "stylesheet")
2. font Resources (preload as "font")
later updates will include support for scripts and modules
The `version` field exported by the React package currently corresponds
to the `@next` release for that build. This updates the build script
to output the same version that is used in the package.json file.
It works by doing a find-and-replace of the React version after the
build has completed. This is a bit weird but it saves us from having
to build the `@next` and `@latest` releases separately; they are
identical except for the version numbers.
Fix matching in the build script.
It's possible to provide a custom bundle name in the case we build deep
imports. We should match those names as a convenience.
The script also calls toLowerCase on requested names but some entries have
upper case now.
* Add fixture for comparing baseline render perf for renderToString and renderToPipeableStream
Modified from ssr2 and https://github.com/SuperOleg39/react-ssr-perf-test
* Implement buffering in pipeable streams
The previous implementation of pipeable streaming (Node) suffered some performance issues brought about by the high chunk counts and innefficiencies with how node streams handle this situation. In particular the use of cork/uncork was meant to alleviate this but these methods do not do anything unless the receiving Writable Stream implements _writev which many won't.
This change adopts the view based buffering techniques previously implemented for the Browser execution context. The main difference is the use of backpressure provided by the writable stream which is not implementable in the other context. Another change to note is the use of standards constructs like TextEncoder and TypedArrays.
* Implement encodeInto during flushCompletedQueues
encodeInto allows us to write directly to the view buffer that will end up getting streamed instead of encoding into an intermediate buffer and then copying that data.
* Switched RulesOfHooks.js to use BigInt. Added test and updated .eslintrc.js to use es2020.
* Added BigInt as readonly global in eslintrc.cjs.js and eslintrc.cjs2015.js
* Added comment to RulesOfHooks.js that gets rid of BigInt eslint error
* Got rid of changes in .eslintrc.js and yarn.lock
* Move global down
Co-authored-by: stephen cyron <stephen.cyron@fdmgroup.com>
Co-authored-by: dan <dan.abramov@gmail.com>
* Remove object-assign polyfill
We really rely on a more modern environment where this is typically
polyfilled anyway and we don't officially support IE with more extensive
polyfilling anyway. So all environments should have the native version
by now.
* Use shared/assign instead of Object.assign in code
This is so that we have one cached local instance in the bundle.
Ideally we should have a compile do this for us but we already follow
this pattern with hasOwnProperty, isArray, Object.is etc.
* Transform Object.assign to now use shared/assign
We need this to use the shared instance when Object.spread is used.
We only export the source directory so Jest and Rollup can access them
during local development and at build time. The files don't exist in the
public builds, so we don't need the export entry, either.
The unstable-shared-subset.js file is not a public module — it's a
private module that the "react" package maps to when it's accessed from
the "react-server" package.
We originally added it because it was required to make our Rollup
configuration work, because at the time only "public" modules could act
as the entry point for a build artifact — that's why it's prefixed with
"unstable". We've since updated our Rollup config to support private
entry points, so we can remove the extra indirection.
* Remove deprecated folder mapping
Node v16 deprecated the use of trailing "/" to define subpath folder
mappings in the "exports" field of package.json.
The recommendation is to explicitly list all our exports. We already do
that for all our public modules. I believe the only reason we have a
wildcard pattern is because our package.json files are also used at
build time (by Rollup) to resolve internal source modules that don't
appear in the final npm artifact.
Changing trailing "/" to "/*" fixes the warnings. See
https://nodejs.org/api/packages.html#subpath-patterns for more info.
Since the wildcard pattern only exists so our build script has access to
internal at build time, I've scoped the wildcard to "/src/*". Because
our public modules are located outside the "src" directory, this means
deep imports of our modules will no longer work: only packages that are
listed in the "exports" field.
The only two affected packages are react-dom and react. We need to be
sure that all our public modules are still reachable. I audited the
exports by comparing the entries to the "files" field in package.json,
which represents a complete list of the files that are included in the
final release artifact.
At some point, we should add an e2e packaging test to prevent
regressions; for now, we should have decent coverage because in CI we
run our Jest test suite against the release artifacts.
* Remove umd from exports
Our expectation is that if you're using the UMD builds, you're not
loading them through a normal module system like require or import.
Instead you're probably copying the files directly or loading them from
a CDN like unpkg.