This commit builds on PR #22260 and makes the following changes:
* Adds a DevTools feature flag for named hooks support. (This allows us to disable it entirely for a build via feature flag.)
* Adds a new Suspense cache for dynamically imported modules. (This allows a component to suspend while importing an external code chunk– like the hook names parsing code).
* DevTools supports a hookNamesModuleLoaderFunction param to import the hook names module. I wish this could be handles as part of the react-devtools-shared package, but I'm not sure how to configure Webpack (4) to serve the chunk from react-devtools-inline. This seemed like a reasonable workaround.
The PR also contains an additional unrelated change:
* Removes pre-fetch optimization (added in DevTools: Improve named hooks network caching #22198). This optimization was mostly only important for cases where sources needed to be re-downloaded, something which we can now avoid in most cases¹ thanks to using cached responses already loaded by the page. (I tested this locally on Facebook and this change has no negative performance impact. There is still some overhead from serializing the JS through the Bridge but that's constant between the two approaches.)
¹ The case where we don't benefit from cached responses is when DevTools are opened after the page has already loaded certain scripts. This seems uncommon enough that I don't think it justified the added complexity of prefetching.
React currently suppress console logs in StrictMode during double rendering. However, this causes a lot of confusion. This PR moves the console suppression logic from React into React Devtools. Now by default, we no longer suppress console logs. Instead, we gray out the logs in console during double render. We also add a setting in React Devtools to allow developers to hide console logs during double render if they choose.
The following APIs have been added to the `react` stable entry point:
* `SuspenseList`
* `startTransition`
* `unstable_createMutableSource`
* `unstable_useMutableSource`
* `useDeferredValue`
* `useTransition`
The following APIs have been added or removed from the `react-dom` stable entry point:
* `createRoot`
* `unstable_createPortal` (removed)
The following APIs have been added to the `react-is` stable entry point:
* `SuspenseList`
* `isSuspenseList`
The following feature flags have been changed from experimental to true:
* `enableLazyElements`
* `enableSelectiveHydration`
* `enableSuspenseServerRenderer`
* Added rudimentary context menu hook and menu UI
* Added backend support for copying a value at a specific path for the inspected element
* Added backend support for storing a value (at a specified path) as a global variable
* Added special casing to enable copying undefined/unserializable values to the clipboard
* Added copy and store-as-global context menu options to selected element props panel
* Store global variables separately, with auto-incremented name (like browsers do)
* Added tests for new copy and store-as-global backend functions
* Fixed some ownerDocument/contentWindow edge cases
* Refactored context menu to support dynamic options
Used this mechanism to add a conditional menu option for inspecting the current value (if it's a function)
* Renamed "safeSerialize" to "serializeToString" and added inline comment
Brian Vaughn
Luna Ruan
Sebastian Markbåge
Dan Abramov