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## Summary
Added an "Applied Configs" section under the Config Overrides panel.
Users will now be able to see the full list of configs applied to the
compiler in the playground. Adds greater discoverability for config
options to override as well. Updated the default config as well to be a
commented config option, so users will start with empty overrides.
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## How did you test this change?
https://github.com/user-attachments/assets/1a57b2d5-0405-4fc8-9990-1747c30181c0
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## Summary
Updated the UI of the React compiler playground. The config, Input, and
Output panels will now span the viewport width when "Show Internals" is
not toggled on. When "Show Internals" is toggled on, the old vertical
accordion tabs are still used. Going to add support for the "Applied
Configs" tabs underneath the "Config Overrides" tab next.
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## How did you test this change?
https://github.com/user-attachments/assets/b8eab028-f58c-4cb9-a8b2-0f098f2cc262
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## Summary
Removed the old `OVERRIDE` pragma to make the source of truth for config
overrides in the left-hand pane. Now, it will automatically update the
output pane each time there is an edit to the config. The old pragma
format is still supported, but it will be overwritten by the config pane
if they are modifying the same flags. Removed the gating on the config
panel so now all users will automatically be able to view it, but it
will be initially collapsed.
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## How did you test this change?
https://github.com/user-attachments/assets/9d4512b9-e203-4ce0-ae95-dd96ff03bbc1
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The compiler playground was crashing at any small syntax errors in the
`Input` panel due to updating the `CompilerErrorDetailOptions` type in
#34401. Updated the option to take in a `ErrorCategory` instead.
---------
Co-authored-by: lauren <poteto@users.noreply.github.com>
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## Summary
Added a "Show Internals" toggle switch to either show only the Config,
Input, Output, and Source Map tabs, or these tabs + all the additional
compiler options. The open/close state of these tabs will be preserved
(unless on page refresh, which is the same as the currently
functionality).
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does the pull request solve?
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## How did you test this change?
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https://github.com/user-attachments/assets/8eb0f69e-360c-4e9b-9155-7aa185a0c018
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6. If you need a debugger, run `yarn test --debug --watch TestName`,
open `chrome://inspect`, and press "Inspect".
7. Format your code with
[prettier](https://github.com/prettier/prettier) (`yarn prettier`).
8. Make sure your code lints (`yarn lint`). Tip: `yarn linc` to only
check changed files.
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10. If you haven't already, complete the CLA.
Learn more about contributing:
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## Summary
Part 3 of adding a "Config Override" panel to the React compiler
playground. Added a button to apply config changes to the Input panel,
as well as making the tab collapsible. Added validation for the the
PluginOptions type (although comes with a bit more boilerplate) to make
it very obvious what the possible config errors could be. Added some
toasts for trying to apply broken configs.
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does the pull request solve?
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## How did you test this change?
https://github.com/user-attachments/assets/63ab8636-396f-45ba-aaa5-4136e62ccccc
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7. Format your code with
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## Summary
Part 2 of adding a "Config Override" panel to the React compiler
playground. Added sync from the config editor (still only accessible
with the "showConfig" param) to the main source code editor. Adding a
valid config to the editor will add/replace the `@OVERRIDE` pragma above
the source code. Additionally refactored the old implementation to
remove `useEffect`s and unnecessary renders.
Realized upon testing that the user experience is quite jarring,
planning to add a `sync` button in the next PR to fix this.
## How did you test this change?
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https://github.com/user-attachments/assets/a71b1b5f-0539-4c00-8d5c-22426f0280f9
## Summary
Part 1 of adding a "Config Override" panel to the React compiler
playground. The panel is placed to the left of the current input
section, and supports converting the comment pragmas in the input
section to a JavaScript-based config. Backwards sync has not been
implemented yet.
NOTE: I have added support for a new `OVERRIDE` type pragma to add
support for Map and Function types. (For now, the old pragma format is
still intact)
## Testing
Example of the config overrides synced to the source code:
<img width="1542" height="527" alt="Screenshot 2025-08-28 at 3 38 13 PM"
src="https://github.com/user-attachments/assets/d46e7660-61b9-4145-93b5-a4005d30064a"
/>
This is mostly to kick off conversation, i think we should go with a
modified version of the implemented approach that i'll describe here.
The playground currently serves two roles. The primary one we think
about is for verifying compiler output. We use it for this sometimes,
and developers frequently use it for this, including to send us repros
if they have a potential bug. The second mode is to help developers
learn about React. Part of that includes learning how to use React
correctly — where it's helpful to see feedback about problematic code —
and also to understand what kind of tools we provide compared to other
frameworks, to make an informed choice about what tools they want to
use.
Currently we primarily think about the first role, but I think we should
emphasize the second more. In this PR i'm doing the worst of both:
enabling all the validations used by both the compiler and the linter by
default. This means that code that would actually compile can fail with
validations, which isn't great.
What I think we should actually do is compile twice, one in
"compilation" mode and once in "linter" mode, and combine the results as
follows:
* If "compilation" mode succeeds, show the compiled output _and_ any
linter errors.
* If "compilation" mode fails, show only the compilation mode failures.
We should also distinguish which case it is when we show errors:
"Compilation succeeded", "Compilation succeeded with linter errors",
"Compilation failed".
This lets developers continue to verify compiler output, while also
turning the playground into a much more useful tool for learning React.
Thoughts?
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/facebook/react/pull/33777).
* #33981
* __->__ #33777
In playground it's helpful to show all errors, even those that don't
completely abort compilation. For example, to help demonstrate that the
compiler catches things like setState in effects. This detects these
errors and ensures we show them.
- Adds @compilationMode(all|infer|syntax|annotation) and
@panicMode(none) directives. This is now shared with our test infra
- Playground still defaults to `infer` mode while tests default to `all`
mode
- See added fixture tests
I had forgotten that our default error reporting threshold was `none`
due to the fact that build pipelines should not throw errors. This
resets it back to throwing on all errors which mostly is the same as the
eslint plugin.
Closes#32014.
The playground's compilation mode is currently set to 'all' along with
reporting all errors.
This tends to be misleading since people usually expect a 1:1 match
between how the playground works with what the compiler does in their
codebase, eg https://github.com/reactwg/react-compiler/discussions/51.
Compiler playground now runs the entire program through
`babel-plugin-react-compiler` instead of a custom pipeline which
previously duplicated function inference logic from `Program.ts`. In
addition, the playground output reflects the tranformed file (instead of
a "virtual file" of manually concatenated functions).
This helps with the following:
- Reduce potential discrepencies between playground and babel plugin
behavior. See attached fixture output for an example where we previously
diverged.
- Let playground users see compiler-inserted imports (e.g. `_c` or
`useFire`)
This also helps us repurpose playground into a more general tool for
compiler-users instead of just for compiler engineers.
- imports and other functions are preserved.
We differentiate between imports and globals in many cases (e.g.
`inferEffectDeps`), so it may be misleading to omit imports in printed
output
- playground now shows other program-changing behavior like position of
outlined functions and hoisted declarations
- emitted compiled functions do not need synthetic names
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/facebook/react/pull/31774).
* #31809
* __->__ #31774
Move environment config parsing for `inlineJsxTransform`,
`lowerContextAccess`, and some dev-only options out of snap (test
fixture). These should now be available for playground via
`@inlineJsxTransform` and `lowerContextAccess`.
Other small change:
Changed zod fields from `nullish()` -> `nullable().default(null)`.
[`nullish`](https://zod.dev/?id=nullish) fields accept `null |
undefined` and default to `undefined`. We don't distinguish between null
and undefined for any of these options, so let's only accept null +
default to null. This also makes EnvironmentConfig in the playground
more accurate. Previously, some fields just didn't show up as
`prettyFormat({field: undefined})` does not print `field`.
Currently the playground is setup as a linked workspace for the
compiler which complicates our yarn workspace setup and means that snap
can sometimes pull in a different version of react than was otherwise
specified.
There's no real reason to have these workspaces combined so let's split
them up.
ghstack-source-id: 56ab064b2f
Pull Request resolved: https://github.com/facebook/react/pull/31081
Summary:
1. Minor refactor to provide a stable API for calling the compiler from the playground
2. Allows spaces in pass names without breaking the appearance of the playground by replacing spaces with in pass tabs
ghstack-source-id: 12a43ad86c
Pull Request resolved: https://github.com/facebook/react/pull/30988
This was a pet peeve where our playground could only compile top level
FunctionDeclarations. Just synthesize a fake identifier if it doesn't
have one.
ghstack-source-id: 882483c79c
Pull Request resolved: https://github.com/facebook/react/pull/30729
Updates the prettier config to format all `.ts` and `.tsx` files in the
repo using the existing defaults and removing overrides.
The first commit in this PR contains the config changes, the second is
just the result of running `yarn prettier-all`.
Summary: Compiler pass tabs are bolded when their contents have changed from previous passes; but currently the HIR and JS tabs are unbolded. Conceptually they should be, if HIR is "changed" from the source code and JS is "changed" from the last IR phase.
In addition, the "show diff" option doesn't make a ton of sense for tabs that either aren't part of the pipeline (EnvironmentConfig) or (maybe more controversially, but imo) passes where the IR representation has changed since the last pass (BuildReactiveFunctions). This diff drops the button from those tabs.
ghstack-source-id: 1d67e2f371
Pull Request resolved: https://github.com/facebook/react/pull/30151
Summary: The playground currently has limited support for Flow files--it tries to parse them if the // flow sigil is on the fist line, but this is often not the case for files one would like to inspect in practice. more importantly, component syntax isn't supported even then, because it depends on the Hermes parser.
This diff improves the state of flow support in the playground to make it more useful: when we see `flow` anywhere in the file, we'll assume it's a flow file, parse it with the Hermes parser, and disable typescript-specific features of Monaco editor.
ghstack-source-id: b99b1568d7
Pull Request resolved: https://github.com/facebook/react/pull/30150
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## Summary
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Explain the **motivation** for making this change. What existing problem
does the pull request solve?
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I have fixed an issue where the display of the HIR diff in the React
Compiler Playground was incorrect. The HIR diff is supposed to show the
pre-change state as the source, but currently, it is showing
EnvironmentConfig as the pre-change state. This PR corrects this by
setting the pre-change state to source instead of EnvironmentConfig.
## How did you test this change?
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before:
after:
After this is merged, I'll add it to .git-blame-ignore-revs. I can't do
it now as the hash will change after ghstack lands this stack.
ghstack-source-id: 054ca869b7
Pull Request resolved: https://github.com/facebook/react/pull/29214
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open `chrome://inspect`, and press "Inspect".
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[prettier](https://github.com/prettier/prettier) (`yarn prettier`).
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Learn more about contributing:
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## Summary
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Explain the **motivation** for making this change. What existing problem
does the pull request solve?
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In the playground, it's hard to see at a glance what compiler passes are
involved in introducing changes.
This PR bolds every pass that introduces a change.
## How did you test this change?
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Before:
<img width="1728" alt="image"
src="https://github.com/facebook/react/assets/5144292/803ca786-0726-4456-b0db-520dc90a6771">
After:
<img width="1728" alt="image"
src="https://github.com/facebook/react/assets/5144292/38885644-00e9-4065-9c44-db533000d13a">
## Summary
Every tab wraps the text around but there is no way to resize it. It was
also hard to use the source map tab. It doesn't occupy the full height
nor is the tab resizable. So I made all the tabs resizable.
> Also,
> * make the source map tab occupy full height
> * make it a teeny tiny bit easier to work with the compiler playground
(especially source map)
## How did you test this change?
https://github.com/facebook/react/assets/91976421/cdec30e8-cadb-4958-8786-31c54ea83bd6
Signed-off-by: abizek <abishekilango@protonmail.com>
Adds supports for hot module reloading (HMR) by resetting the cache if a hash of the source file changes. This is enabled via a compiler flag, but also enabled automatically via the babel plugin when NODE_ENV=development.
ghstack-source-id: 5cd1ad5c89
Pull Request resolved: https://github.com/facebook/react-forget/pull/2951
This PR makes all packages share the same typescript version and updates us to
latest versions of typescript, ts-node, typescript-eslint/eslint-plugin and
typescript-eslint/parser.
I also noticed that the tsconfig we were extending (node18-strictest) was
deprecated, so I switched us over to one that's more up to date.
Also had to make a couple of small changes to the playground so that continues
to build correctly.
Infer if a function is a component or hook when we're deciding to compile a
function and store that in the environment.
This is used in passes like InferReferenceEffects rather than having to re-parse
the name in each pass.
filepath
Internal rollout currently has a good number of test failures.
`enableEmitInstrumentForget` can help developers understand which functions /
files they should look at:
```
// input
function Foo() {
userCode();
// ...
}
// output
function Foo() {
if (__DEV__ && inE2eTestMode) {
logRender("Foo", "/path/to/filename.js");
}
const $ = useMemoCache(...);
userCode();
}
```
Eugene Choi
Joseph Savona
mofeiZ
Aditya Subramanyam
Mike Vitousek
Jan Kassens
Joe Savona
NISHIZAWA Shuntaro
Jack Youstra
Abishek Ilango
Jason Bonta
Mofei Zhang
Sathya Gunasekaran