## Summary
This PR adds a 'Layout' selector to the devtools shell main example, as
well as a resizable split pane, allowing more realistic testing of how
the devtools behaves when used in a vertical or horizontal layout and at
different sizes (e.g. when resizing the Chrome Dev Tools pane).
## How did you test this change?
https://github.com/user-attachments/assets/81179413-7b46-47a9-bc52-4f7ec414e8be
## Summary
This PR adds a "perf regression tests" page to react-devtools-shell.
This page is meant to be used as a performance sanity check we will run
whenever we release a new version or finish a major refactor.
Similar to other pages in the shell, this page can load the inline
version of devtools and a test react app on the same page. But this page
does not load devtools automatically like other pages. Instead, it
provides a button that allows us to load devtools on-demand, so that we
can easily compare perf numbers without devtools against the numbers
with devtools.
<img width="561" alt="image"
src="https://user-images.githubusercontent.com/1001890/184059633-e4f0852c-8464-4d94-8064-1684eee626f4.png">
As a first step, this page currently only contain one test:
mount/unmount a large subtree. This is to catch perf issues that
devtools can cause on the react applications it's running on, which was
once a bug fixed in #24863.
In the future, we plan to add:
- more test apps covering different scenarios
- perf numbers within devtools (e.g. initial load)
## How did you test this change?
In order to show this test app can actually catch the perf regression
it's aiming at, I reverted #24863 locally. Here is the result:
https://user-images.githubusercontent.com/1001890/184059214-9c9b308c-173b-4dd7-b815-46fbd7067073.mov
As shown in the video, the time it takes to unmount the large subtree
significantly increased after DevTools is loaded.
For comparison, here is how it looks like before the fix was reverted:
<img width="452" alt="image"
src="https://user-images.githubusercontent.com/1001890/184059743-0968bc7d-4ce4-42cd-b04a-f6cbc078d4f4.png">
## about the `requestAnimationFrame` method
For this test, I used `requestAnimationFrame` to catch the time when
render and commit are done. It aligns very well with the numbers
reported by Chrome DevTools performance profiling. For example, in one
run, the numbers reported by my method are
<img width="464" alt="image"
src="https://user-images.githubusercontent.com/1001890/184060228-990a4c75-f594-411a-9f85-fa5532ec8c37.png">
They are very close to the numbers reported by Chrome profiling:
<img width="456" alt="image"
src="https://user-images.githubusercontent.com/1001890/184060355-a15d1ec5-c296-4016-9c83-03e761f387e3.png">
<img width="354" alt="image"
src="https://user-images.githubusercontent.com/1001890/184060375-19029010-3aed-4a23-890e-397cdba86d9e.png">
`<Profiler>` is not able to catch this issue here.
If you are aware of a better way to do this, please kindly share with
me.
This PR adds an e2e regression app to the react-devtools-shell package. This app:
* Has an app.js and an appLegacy.js entrypoint because apps prior to React 18 need to use ReactDOM.render. These files will create and render multiple test apps (though they currently only render the List)
* Moved the ListApp out of the e2e folder and into an e2e-apps folder so that both e2e and e2e-regression can use the same test apps
* Creates a ListAppLegacy app because prior to React 16.8 hooks didn't exist.
* Added a devtools file for the e2e-regression
* Modifies the webpack config so that the e2e-regression React app can use different a different React version than DevTools
This is being done so that we can embed DevTools within the new React (beta) docs.
The primary changes here are to `react-devtools-inline/backend`:
* Add a new `createBridge` API
* Add an option to the `activate` method to support passing in the custom bridge object.
The `react-devtools-inline` README has been updated to include these new methods.
To verify these changes, this commit also updates the test shell to add a new entry-point for multiple DevTools.
This commit also replaces two direct calls to `window.postMessage()` with `bridge.send()` (and adds the related Flow types).
