Each integrator: browser extension, Chrome DevTools Frontend fork,
Electron shell must define and provide `fetchFileWithCaching` in order
for DevTools to be able to fetch application resources, such as scripts
or source maps.
More specifically, if this is available, React DevTools will be able to
symbolicate source locations for component frames, owner stacks,
"suspended by" Promises call frames.
This will be available with the next release of React DevTools.
The `useOpenResource` hook is now used to open links. Currently, the
`<>` icon for the component stacks and the link in the bottom of the
components stack. But it'll also be used for many new links like stacks.
If this new option is configured, and this is a local file then this is
opened directly in the external editor. Otherwise it fallbacks to open
in the Sources tab or whatever the standalone or inline is configured to
use.
<img width="453" height="252" alt="Screenshot 2025-07-24 at 4 09 09 PM"
src="https://github.com/user-attachments/assets/04cae170-dd30-4485-a9ee-e8fe1612978e"
/>
I prominently surface this option in the Source pane to make it
discoverable.
<img width="588" height="144" alt="Screenshot 2025-07-24 at 4 03 48 PM"
src="https://github.com/user-attachments/assets/0f3a7da9-2fae-4b5b-90ec-769c5a9c5361"
/>
When this is configured, the "Open in Editor" is hidden since that's
just the default. I plan on deprecating this button to avoid having the
two buttons going forward.
Notably there's one exception where this doesn't work. When you click an
Action or Event listener it takes you to the Sources tab and you have to
open in editor from there. That's because we use the `inspect()`
mechanism instead of extracting the source location. That's because we
can't do the "throw trick" since these can have side-effects. The Chrome
debugger protocol would solve this but it pops up an annoying dialog. We
could maybe only attach the debugger only for that case. Especially if
the dialog disappears before you focus on the browser again.
In RSC and other stacks now we use a lot of `ReactFunctionLocation` type
to represent the location of a function. I.e. the location of the
beginning of the function (the enclosing line/col) that is represented
by the "Source" of the function. This is also what the parent Component
Stacks represents.
As opposed to `ReactCallSite` which is what normal stack traces and
owner stacks represent. I.e. the line/column number of the callsite into
the next function.
We can start sharing more code by using the `ReactFunctionLocation` type
to represent the component source location and it also helps clarify
which ones are function locations and which ones are callsites as we
start adding more stack traces (e.g. for async debug info and owner
stack traces).
## Summary
This tool leverages DevTools to get the component tree from the
currently open React App. This gives realtime information to agents
about the state of the app.
## How did you test this change?
Tested integration with Claude Desktop
## Summary
Exposes the APIs needed by React Native DevTools (Fusebox) to implement
the "view element source" and "view attribute source" features.
## How did you test this change?
1. `yarn build` in `react-devtools-fusebox`
2. Copy artifacts to rn-chrome-devtools-frontend
3. Write some additional glue code to implement
`viewElementSourceFunction` in our CDT fork.
4. Test the feature manually.
https://github.com/facebook/react/assets/2246565/12667018-100a-4b3f-957a-06c07f2af41a
## Summary
Enables the inspected element context menu in React Native DevTools
(Fusebox).
## How did you test this change?
1. `yarn build` in `react-devtools-fusebox`
2. Copy artifacts to rn-chrome-devtools-frontend
3. Manually test the context menu
https://github.com/facebook/react/assets/2246565/b35cc20f-8d67-43b0-b863-7731e10fffac
NOTE: The serialised values sometimes expose React internals (e.g. Hook
data structures instead of just the values), but that seems to be a
problem equally on web, so I'm going for native<->web parity here.
## Summary
The `react-devtools-fusebox` private package is used in the React Native
DevTools (Fusebox) frontend by checking build artifacts into RN's
[fork]([`facebookexperimental/rn-chrome-devtools-frontend`](https://github.com/facebookexperimental/rn-chrome-devtools-frontend))
of the Chrome DevTools (CDT) repo - see
https://github.com/facebookexperimental/rn-chrome-devtools-frontend/pull/22.
Currently, the CDT fork also includes a [manually written TypeScript
definition
file](1d5f8d5209/front_end/third_party/react-devtools/package/frontend.d.ts)
which describes `react-devtools-fusebox`'s API. This PR moves that file
into the React repo, next to the implementation of
`react-devtools-fusebox`, so we can update it atomically with changes to
the package.
As this is the first bit of TypeScript in this repo, the PR adds minimal
support for formatting `.d.ts` files with Prettier. It also opts out
`react-devtools-fusebox/dist/` from linting/formatting as a drive-by
fix.
For now, we'll just maintain the `.d.ts` file manually, but we could
consider leveraging
[`flow-api-translator`](https://www.npmjs.com/package/flow-api-translator)
to auto-generate it in the future.
## How did you test this change?
Build `react-devtools-fusebox`, observe that `dist/frontend.d.ts`
exists.
Support propagating theme from Chrome DevTools frontend, the field is
optional.
Next step, which is out of scope of this project and general improvement
for React DevTools: teach RDT to listen to theme changes and if the
theme preference is set to `auto` in settings, update the theme
accordingly with the browser devtools.
## Summary
Stacked on https://github.com/facebook/react/pull/28552. Review only the
[last commit at the
top](c69952f1bf).
These changes add new package `react-devtools-fusebox`, which is the
entrypoint for the RDT Frontend, which will be used in Chrome DevTools
panel. The main differences from other frontend shells (extension,
standalone) are:
1. This package builds scripts in ESM format, this is required by Chrome
DevTools, see webpack config:
c69952f1bf/packages/react-devtools-fusebox/webpack.config.frontend.js (L50-L52)
2. The build includes styles in a separate `.css` file, which is
required for Chrome DevTools: styles are loaded lazily once panel is
mounted.
