Stacked on https://github.com/facebook/react/pull/30597 and whats under
it. See [this
commit](59b4efa723).
With this change, the initial values for console patching settings are
propagated from hook (which is the source of truth now, because of
https://github.com/facebook/react/pull/30596) to the UI. Instead of
reading from `localStorage` the frontend is now requesting it from the
hook. This happens when settings modal is rendered, and wrapped in a
transition. Also, this is happening even if settings modal is not opened
yet, so we have enough time to fetch this data without displaying loader
or similar UI.
This reverts #19603.
Before:
<img width="724" alt="Screenshot 2024-08-28 at 12 07 29 AM"
src="https://github.com/user-attachments/assets/0613088f-c013-4f1c-92c3-fbdae8c1f109">
After:
<img width="771" alt="Screenshot 2024-08-28 at 12 08 13 AM"
src="https://github.com/user-attachments/assets/eef21bee-d11f-4f0a-9147-053a163f720f">
Consensus seems to be that while the purple on is a bit clearer and
easier to read. The purple is not on brand so it doesn't look like
React. It looks ugly. It's distracting (too eye catching). Taking away
attention from other tabs in an unfair way.
It also gets worse with more tabs added. We plan on both adding another
tab and panes inside other tabs (elements/sources) soon. Each needs to
be marked somehow as part of React but spelling it out is too long.
Putting inside a second tab means two clicks and takes away real-estate
from our extension and doesn't solve the problem with extension panes in
other tabs. We also plan on adding multiple different tracks to the
Performance tab which also needs a name other than just React and
spelling out React as a prefix is too long. The Emoji is too
distracting. So it seems best to uniformly apply the symbol - albeit it
might just look like a dot to many.
Dark mode looks close to on brand:
<img width="1089" alt="Screenshot 2024-08-28 at 12 32 50 AM"
src="https://github.com/user-attachments/assets/7175a540-4241-4c26-9e4d-4d367873af57">
## Summary
This PR bumps Flow all the way to the latest 0.245.2.
Most of the suppressions comes from Flow v0.239.0's change to include
undefined in the return of `Array.pop`.
I also enabled `react.custom_jsx_typing=true` and added custom jsx
typing to match the old behavior that `React.createElement` is
effectively any typed. This is necessary since various builtin
components like `React.Fragment` is actually symbol in the React repo
instead of `React.AbstractComponent<...>`. It can be made more accurate
by customizing the `React$CustomJSXFactory` type, but I will leave it to
the React team to decide.
## How did you test this change?
`yarn flow` for all the renderers
First, this basically reverts
1f3892ef8c
to use a Map/Set to track what is forced to suspend/error again instead
of flags on the Instance. The difference is that now the key in the
Fiber itself instead of the ID. Critically this avoids the
fiberToFiberInstance map to look up whether or not a Fiber should be
forced to suspend when asked by the renderer.
This also allows us to force suspend/error on filtered instances. It's a
bit unclear what should happen when you try to Suspend or Error a child
but its parent boundary is filtered. It was also inconsistent between
Suspense and Error due to how they were implemented.
I think conceptually you're trying to simulate what would happen if that
Component errored or suspended so it would be misleading if we triggered
a different boundary than would happen in real life. So I think we
should trigger the nearest unfiltered Fiber, not the nearest Instance.
The consequence of this however is that if this instance was filtered,
there's no way to undo it without refreshing or removing the filter.
This is an edge case though since it's unusual you'd filter these in the
first place.
It used to be that Suspense walked the store in the frontend and Error
walked the Fibers in the backend. They also did this somewhat eagerly.
This simplifies and unifies the model by passing the id of what you
clicked in the frontend and then we walk the Fiber tree from there in
the backend to lazily find the boundary. However I also eagerly walk the
tree at first to find whether we have any Suspense or Error boundary
parents at all so we can hide the buttons if not.
This also implements it to work with VirtualInstances using #30865. I
find the nearest Fiber Instance downwards filtered or otherwise. Then
from its parent we find the nearest Error or Suspense boundary. That's
because VirtualInstance will always have their inner Fiber as an
Instance but they might not have their parent since it might be
filtered. Which would potentially cause us to skip over a filtered
parent Suspense boundary.
Stacked on #30842.
This adds a filter to be able to exclude Components from a certain
environment. Default to Client or Server.
The available options are computed into a dropdown based on the names
that are currently used on the page (or an option that were previously
used). In addition to the hardcoded "Client". Meaning that if you have
Server Components on the page you see "Server" or "Client" as possible
options but it can be anything if there are multiple RSC environments on
the page.
"Client" in this case means Function and Class Components in Fiber -
excluding built-ins.
If a Server Component has two environments (primary and secondary) then
both have to be filtered to exclude it.
We don't show the option at all if there are no Server Components used
in the page to avoid confusing existing users that are just using Client
Components and wouldn't know the difference between Server vs Client.
<img width="815" alt="Screenshot 2024-08-30 at 12 56 42 AM"
src="https://github.com/user-attachments/assets/e06b225a-e85d-4cdc-8707-d4630fede19e">
These don't have their own time since they don't take up any time to
render but they show up in the tree for context. However they never
render themselves. Their base tree time is the base time of their
children. This way they take up the same space as their combined
children in the Profiler tree. (Instead of leaving a blank line which
they did before this PR.)
The frontend doesn't track the difference between a virtual instance and
a Fiber that didn't render this update. This might be a bit confusing as
to why it didn't render. I add the word "client" to make it a bit
clearer and works for both. We should probably have different verbiage
here based on it is a Server Component or something else.
<img width="1103" alt="Screenshot 2024-08-26 at 5 00 47 PM"
src="https://github.com/user-attachments/assets/87b811d4-7024-466a-845d-542493ed3ca2">
I also took the opportunity to remove idToTreeBaseDurationMap and
idToRootMap maps. Cloning the Map isn't really all that super fast
anyway and it means we have to maintain the map continuously as we
render. Instead, we can track it on the instances and then walk the
instances to create a snapshot when starting to profile. This isn't as
fast but really fast too and requires less bookkeeping while rendering
instead which is more sensitive than that one snapshot in the beginning.
Currently you can jump to definition of a function by right clicking
through the context menu. However, it's pretty difficult to discover.
This makes the functions clickable to jump to definition - like links.
This uses the same styling as we do for links (which are btw only
clickable if they're not editable). Including cursor: pointer.
I added a background on hover which follows the same pattern as the
owners list.
I also dropped the ƒ prefix when displaying functions. This is a cute
short cut and there's precedence in how Chrome prints functions in the
console *if* the function's toString would've had a function prefix like
if it was a function declaration or expression. It does not do this for
arrow functions or object methods.
Elsewhere in the JS ecosystem this isn't really used anywhere. It
invites more questions than it answers.
The parenthesis and curlies are enough. There's no ambiguity here since
strings have quotations. It looks better with just its object method
form. Keeping it simple seems best. To my eyes this flows better because
I'm used to looking at function syntax but not weird "f"s.
Before:
<img width="433" alt="Screenshot 2024-08-20 at 11 55 09 PM"
src="https://github.com/user-attachments/assets/9dd50da6-598f-4291-9e24-1cdc7200dc9e">
After:
<img width="388" alt="Screenshot 2024-08-20 at 11 46 01 PM"
src="https://github.com/user-attachments/assets/dd988e14-412e-4deb-8c8c-26a54be8331f">
After (Hover):
<img width="389" alt="Screenshot 2024-08-20 at 11 46 31 PM"
src="https://github.com/user-attachments/assets/6fb4ebed-5dc1-448a-8e4d-b6d4f3903329">
Alternative to https://github.com/facebook/react/pull/30667.
Basically wrap every section in a `div` with the same class, and only
apply `border-bottom` for every instance, except for the last child. We
are paying some cost by having more divs, but thats more explicit.
Same principle as #30555. We shouldn't be throttling the UI to make it
feel less snappy. Instead, we should use back-pressure to handle it.
Normally the browser handles it automatically with frame aligned events.
E.g. if the thread can't keep up with sync updates it doesn't send each
event but the next one. E.g. pointermove or resize.
However, it is possible that we end up queuing too many events if the
frontend can't keep up but the solution to this is the same as mentioned
in #30555. I.e. to track the last message and only send after we get a
response.
I still keep the throttle to persist the selection since that affects
the disk usage and doesn't have direct UX effects.
The main motivation for this change though is that lodash throttle
doesn't rely on timers but Date.now which makes it incompatible with
most jest helpers which means I can't write tests against these
functions properly.
[`react-window` disables `pointerEvents` while scrolling meaning you
can't click anything while
scrolling.](https://github.com/bvaughn/react-window/issues/128).
This means that the first click when you stop the scroll with inertial
scrolling doesn't get registered. This is suuuper annoying. This might
make sense when you click to stop on a more intentional UI but it
doesn't makes sense in a list like this because we eagerly click things
even on mousedown.
This PR just override that to re-enable pointer events.
Supposedly this is done for performance but that might be outdated
knowledge. I haven't observed any difference so far.
If we discover that it's a perf problem, there's another technique we
can use where we call `ownerDocument.elementFromPoint(e.pageX, e.pageY)`
and then dispatch the event against that element. But let's try the
simplest approach first?
There's two problems. The biggest one is that it turns out that Chrome
is throttling looping timers that we're using both while polling and for
batching bridge traffic. This means that bridge traffic a lot of the
time just slows down to 1 second at a time. No wonder it feels sluggish.
The only solution is to not use timers for this.
Even when it doesn't like in Firefox the batching into 100ms still feels
too sluggish.
The fix I use is to batch using a microtask instead so we can still
batch multiple commands sent in a single event but we never artificially
slow down an interaction.
I don't think we've reevaluated this for a long time since this was in
the initial commit of DevTools to this repo. If it causes other issues
we can follow up on those.
We really shouldn't use timers for debouncing and such. In fact, React
itself recommends against it because we have a better technique with
scheduling in Concurrent Mode. The correct way to implement this in the
bridge is using a form of back-pressure where we don't keep sending
messages until we get a message back and only send the last one that
matters. E.g. when moving the cursor over a the elements tab we
shouldn't let the backend one-by-one move the DOM node to each one we
have ever passed. We should just move to the last one we're currently
hovering over. But this can't be done at the bridge layer since it
doesn't know if it's a last-one-wins or imperative operation where each
one needs to be sent. It needs to be done higher. I'm not currently
seeing any perf problems with this new approach but I'm curious on React
Native or some thing. RN might need the back-pressure approach. That can
be a follow up if we ever find a test case.
Finally, the other problem is that we use a Suspense boundary around the
Element Inspection. Suspense boundaries are for things that are expected
to take a long time to load. This shows a loading state immediately. To
avoid flashing when it ends up being fast, React throttles the reveal to
200ms. This means that we take a minimum of 200ms to show the props. The
way to show fast async data in React is using a Transition (either using
startTransition or useDeferredValue). This lets the old value remaining
in place while we're loading the next one.
We already implement this using `inspectedElementID` which is the async
one. It would be more idiomatic to implement this with useDeferredValue
rather than the reducer we have now but same principle. We were just
using the wrong ID in a few places so when it synchronously updated they
suspended. So I just made them use the inspectedElementID instead.
Then I can simply remove the Suspense boundary. Now the selection
updates in the tree view synchronously and the sidebar lags a frame or
two but it feels instant. It doesn't flash to white between which is
key.
Stacked on #30490.
This is in the same spirit but to clarify the difference between what is
React Native vs part of any generic Host. We used to use "Native" to
mean three different concepts. Now "Native" just means React Native.
E.g. from the frontend's perspective the Host can be
Highlighted/Inspected. However, that in turn can then be implemented as
either direct DOM manipulation or commands to React Native. So frontend
-> backend is "Host" but backend -> React Native is "Native" while
backend -> DOM is "Web".
Rename NativeElementsPanel to BuiltinElementsPanel. This isn't a React
Native panel but one part of the surrounding DevTools. We refer to Host
more as the thing running React itself. I.e. where the backend lives.
The runtime you're inspecting. The DevTools itself needs a third term.
So I went with "Builtin".
I need to start clarifying where things are really actually Fibers and
where they're not since I'm adding Server Components as a separate type
of component instance which is not backed by a Fiber.
Nothing in the front end should really know anything about what kind of
renderer implementation we're inspecting and indeed it's already not
always a "Fiber" in the legacy renderer.
We typically refer to this as a "Component Instance" but the front end
currently refers to it as an Element as it historically grew from the
browser DevTools Elements tab.
I also moved the renderer.js implementation into the `backend/fiber`
folder. These are at the same level as `backend/legacy`. This clarifies
that anything outside of this folder ideally shouldn't refer to a
"Fiber".
console.js and profilingHooks.js unfortunately use Fibers a lot which
needs further refactoring. The profiler frontend also uses the term
alot.
## Summary
- While rolling out RDT 5.2.0 on Fusebox, we've discovered that context
menus don't work well with this environment. The reason for it is the
context menu state implementation - in a global context we define a map
of registered context menus, basically what is shown at the moment (see
deleted Contexts.js file). These maps are not invalidated on each
re-initialization of DevTools frontend, since the bundle
(react-devtools-fusebox module) is not reloaded, and this results into
RDT throwing an error that some context menu was already registered.
- We should not keep such data in a global state, since there is no
guarantee that this will be invalidated with each re-initialization of
DevTools (like with browser extension, for example).
- The new implementation is based on a `ContextMenuContainer` component,
which will add all required `contextmenu` event listeners to the
anchor-element. This component will also receive a list of `items` that
will be displayed in the shown context menu.
- The `ContextMenuContainer` component is also using
`useImperativeHandle` hook to extend the instance of the component, so
context menus can be managed imperatively via `ref`:
`contextMenu.current?.hide()`, for example.
- **Changed**: The option for copying value to clipboard is now hidden
for functions. The reasons for it are:
- It is broken in the current implementation, because we call
`JSON.stringify` on the value, see
`packages/react-devtools-shared/src/backend/utils.js`.
- I don't see any reasonable value in doing this for the user, since `Go
to definition` option is available and you can inspect the real code and
then copy it.
- We already filter out fields from objects, if their value is a
function, because the whole object is passed to `JSON.stringify`.
## How did you test this change?
### Works with element props and hooks:
- All context menu items work reliably for props items
- All context menu items work reliably or hooks items
https://github.com/facebook/react/assets/28902667/5e2d58b0-92fa-4624-ad1e-2bbd7f12678f
### Works with timeline profiler:
- All context menu items work reliably: copying, zooming, ...
- Context menu automatically closes on the scroll event
https://github.com/facebook/react/assets/28902667/de744cd0-372a-402a-9fa0-743857048d24
### Works with Fusebox:
- Produces no errors
- Copy to clipboard context menu item works reliably
https://github.com/facebook/react/assets/28902667/0288f5bf-0d44-435c-8842-6b57bc8a7a24
## Summary
The Forget codename needs to be hidden from the UI to avoid confusion.
Going forward, we'll be referring to this set of features as part of the
larger React compiler. We'll be describing the primary feature that
we've built so far as auto-memoization, and this badge helps devs see
which components have been automatically memoized by the compiler.
## How did you test this change?
- force Forget badge on with and without the presence of other badges
- confirm colors/UI in light and dark modes
- force badges on for `ElementBadges`, `InspectableElementBadges`,
`IndexableElementBadges`
- Running yarn start in packages/react-devtools-shell
[demo
video](https://github.com/facebook/react/assets/973058/fa829018-7644-4425-8395-c5cd84691f3c)
Stacked on https://github.com/facebook/react/pull/28351, please review
only the last commit.
Top-level description of the approach:
1. Once user selects an element from the tree, frontend asks backend to
return the inspected element, this is where we simulate an error
happening in `render` function of the component and then we parse the
error stack. As an improvement, we should probably migrate from custom
implementation of error stack parser to `error-stack-parser` from npm.
2. When frontend receives the inspected element and this object is being
propagated, we create a Promise for symbolicated source, which is then
passed down to all components, which are using `source`.
3. These components use `use` hook for this promise and are wrapped in
Suspense.
Caching:
1. For browser extension, we cache Promises based on requested resource
+ key + column, also added use of
`chrome.devtools.inspectedWindow.getResource` API.
2. For standalone case (RN), we cache based on requested resource url,
we cache the content of it.
`_debugSource` was removed in
https://github.com/facebook/react/pull/28265.
This PR migrates DevTools to define `source` for Fiber based on
component stacks. This will be done lazily for inspected elements, once
user clicks on the element in the tree.
`DevToolsComponentStackFrame.js` was just copy-pasted from the
implementation in `ReactComponentStackFrame`.
Symbolication part is done in
https://github.com/facebook/react/pull/28471 and stacked on this commit.
There is a weird behaviour in all shells of RDT: when user opens
`Components` tab and scrolls down a tree (without any prior click or
focus event), and then clicks on some element, the `click` event will
not be fired. Because `click` event hasn't been fired, the `focus` event
is fired for the whole list and we pre-select the first (root) element
in the tree:
034130c02f/packages/react-devtools-shared/src/devtools/views/Components/Tree.js (L217-L226)
Check the demo (before) what is happening. I don't know exactly why
`click` event is not fired there, but it only happens:
1. For elements, which were not previously rendered (for virtualization
purposes).
2. When HTML-element (div), which represents the container for the tree
was not focused previously.
Unlike the `click` event, the `mousedown` event is fired consistently.
### Before
https://github.com/facebook/react/assets/28902667/9f3ad75d-55d0-4c99-b2d0-ead63a120ea0
### After
https://github.com/facebook/react/assets/28902667/e34816be-644c-444c-8e32-562a79494e44
Tested that it works in all shells, including the select / deselect
features (with `metaKey` param in event).
Following https://github.com/facebook/react/pull/28265, this should
disable location-based component filters.
```
// Following __debugSource removal from Fiber, the new approach for finding the source location
// of a component, represented by the Fiber, is based on lazily generating and parsing component stack frames
// To find the original location, React DevTools will perform symbolication, source maps are required for that.
// In order to start filtering Fibers, we need to find location for all of them, which can't be done lazily.
// Eager symbolication can become quite expensive for large applications.
```
I am planning to publish a patch version of RDT soon, so I think its
better to remove this feature, instead of shipping it in a broken state.
The reason for filtering out these filters is a potential cases, where
we load filters from the backend (like in RN, where we storing some
settings on device), or these filters can be stored in user land
(`window.__REACT_DEVTOOLS_COMPONENT_FILTERS__`).
Explicitly tested the case when:
1. Load current RDT extension, add location-based component filter
2. Reload the page and observe that previously created component filter
is preserved
3. Re-load RDT extension with these changes, observe there is no
previously created component filter and user can't create a new
location-based filter
4. Reload RDT extension without these changes, no location-based filters
saved, user can create location-based filters
In our custom implementation for handling modals dismiss signal, we use
element's `ownerDocument` field, which expectedly doesn't work well with
shadow root. Now using
[`getRootNode`](https://developer.mozilla.org/en-US/docs/Web/API/Node/getRootNode)
instead of `ownerDocument` to support shadow root case.
Without this, if RDT Frontend is hosted inside the shadow root, the
modal gets closed after any click, including on the buttons hosted by
modal:
00d42ac354/packages/react-devtools-shared/src/devtools/views/hooks.js (L228-L238)
Test plan:
- Modals work as expected for Chrome DevTools integration
- Modals work as expected at every other surfaces: browser extension,
electron wrapper for RN, inline version for web
This Flow upgrade includes 2 fixes:
- Remove `React$StatelessFunctionalComponent` as that was replaced by
just `React$AbstractComponent` as Flow doesn't make any guarantees, see
the Flow change here:
521317c48f
- Flow no longer allows `number` type indexing into objects which
discovered an incorrect type that is actually an array of the data.
Used this command to upgrade
```
yarn add -W flow-bin flow-remove-types hermes-parser hermes-eslint
```
and ran `yarn flow-ci` to check for errors in different configurations.
Adds `Forget` badge to all relevant components.
Changes:
- If component is compiled with Forget and using a built-in
`useMemoCache` hook, it will have a `Forget` badge next to its display
name in:
- components tree
- inspected element view
- owners list
- Such badges are indexable, so Forget components can be searched using
search bar.
Fixes:
- Displaying the badges for owners list inside the inspected component
view
Implementation:
- React DevTools backend is responsible for identifying if component is
compiled with Forget, based on `fiber.updateQueue.memoCache`. It will
wrap component's display name with `Forget(...)` prefix before passing
operations to the frontend. On the frontend side, we will parse the
display name and strip Forget prefix, marking the corresponding element
by setting `compiledWithForget` field. Almost the same logic is
currently used for HOC display names.
Had these stashed for some time, it includes:
- Some refactoring to remove unnecessary `FlowFixMe`s and type castings
via `any`.
- Optimized version of parsing component names. We encode string names
to utf8 and then pass it serialized from backend to frontend in a single
array of numbers. Previously we would call `slice` to get the
corresponding encoded string as a subarray and then parse each
character. New implementation skips `slice` step and just receives
`left` and `right` ranges for the string to parse.
- Early `break` instead of `continue` when Store receives unexpected
operation, like removing an element from the Store, which is not
registered yet.
There are not so many changes, most of them are changing imports,
because I've moved types for UI in a single file.
In https://github.com/facebook/react/pull/27357 I've added support for
pausing polling events: when user inspects an element, we start polling
React DevTools backend for updates in props / state. If user switches
tabs, extension's service worker can be killed by browser and this
polling will start spamming errors.
What I've missed is that we also have a separate call for this API, but
which is executed only once when user selects an element. We don't
handle promise rejection here and this can lead to some errors when user
selects an element and switches tabs right after it.
The only change here is that this API now has
`shouldListenToPauseEvents` param, which is `true` for polling, so we
will pause polling once user switches tabs. It is `false` by default, so
we won't pause initial call by accident.
af8beeebf6/packages/react-devtools-shared/src/backendAPI.js (L96)
Some context:
- When user selects an element in tree inspector, we display current
state of the component. In order to display really current state, we
start polling the backend to get available updates for the element.
Previously:
- Straight-forward sending an event to get element updates each second.
Potential race condition is not handled in any form.
- If user navigates from the page, timeout wouldn't be cleared and we
would potentially throw "Timed out ..." error.
- Bridge disconnection is not handled in any form, if it was shut down,
we could spam with "Timed out ..." errors.
With these changes:
- Requests are now chained, so there can be a single request at a time.
- Handling both navigation and shut down events.
This should reduce the number of "Timed out ..." errors that we see in
our logs for the extension. Other surfaces will also benefit from it,
but not to the full extent, as long as they utilize
"resumeElementPolling" and "pauseElementPolling" events.
Tested this on Chrome, running React DevTools on multiple tabs,
explicitly checked the case when service worker is in idle state and we
return back to the tab.
Fixes https://github.com/facebook/react/issues/27119,
https://github.com/facebook/react/issues/27185.
Fixed:
- React DevTools now works as expected when user performs in-tab
navigation, previously it was just stuck.
https://github.com/facebook/react/assets/28902667/b11c5f84-7155-47a5-8b5a-7e90baca5347
- When user closes browser DevTools panel, we now do some cleanup to
disconnect ports and emit shutdown event for bridge. This should fix the
issue with registering duplicated fibers with the same id in Store.
Changed:
- We reconnect proxy port once in 25 seconds, in order to [keep service
worker
alive](https://developer.chrome.com/docs/extensions/whatsnew/#m110-sw-idle).
- Instead of unregistering dynamically injected content scripts, wen now
get list of already registered scripts and filter them out from scripts
that we want to inject again, see dynamicallyInjectContentScripts.js.
- Split `main.js` and `background.js` into multiple files.
Tested on Chromium and Firefox browsers.
When some element is inspected in DevTools, we have a polling which
updates the data for this element.
Sometimes when service worker dies or bridge is getting shutdown, we
continue to poll this data and will spam with the same "timed out
error".
<img width="1728" alt="Screenshot 2023-07-28 at 17 39 23"
src="https://github.com/facebook/react/assets/28902667/220c4504-1ccc-4e87-9d78-bfff8b708230">
These changes add an explicit check that polling is allowed only while
bridge is alive.
## Summary
>Warning: Received NaN for the `children` attribute. If this is
expected, cast the value to a string.
Fixes this warning, when we try to display NaN as NaN in key-value list.
Just a small upgrade to keep us current and remove unused suppressions
(probably fixed by some upgrade since).
- `*` is no longer allowed and has been an alias for `any` for a while
now.
- substr is Annex B
- substring silently flips its arguments if they're in the "wrong order", which is confusing
- slice is better than sliced bread (no pun intended) and also it works the same way on Arrays so there's less to remember
---
> I'd be down to just lint and enforce a single form just for the potential compression savings by using a repeated string.
_Originally posted by @sebmarkbage in https://github.com/facebook/react/pull/26663#discussion_r1170455401_
## Summary
Removing `enableNamedHooksFeature`, `enableProfilerChangedHookIndices`,
`enableProfilerComponentTree` feature flags, they are the same for all
configurations.
## Summary
This pull request aims to improve the maintainability of the codebase by
consolidating types and constants that are shared between the backend
and frontend. This consolidation will allow us to maintain backwards
compatibility in the frontend in the future.
To achieve this, we have moved the shared types and constants to the
following blessed files:
- react-devtools-shared/src/constants
- react-devtools-shared/src/types
- react-devtools-shared/src/backend/types
- react-devtools-shared/src/backend/NativeStyleEditor/types
Please note that the inclusion of NativeStyleEditor in this list is
temporary, and we plan to remove it once we have a better plugin system
in place.
## How did you test this change?
I have tested it by running `yarn flow dom-node`, which reports no
errors.
Added an explicit type to all $FlowFixMe suppressions to reduce
over-suppressions of new errors that might be caused on the same lines.
Also removes suppressions that aren't used (e.g. in a `@noflow` file as
they're purely misleading)
Test Plan:
yarn flow-ci
## Hoistables
In the original implementation of Float, all hoisted elements were
treated like Resources. They had deduplication semantics and hydrated
based on a key. This made certain kinds of hoists very challenging such
as sequences of meta tags for `og:image:...` metadata. The reason is
each tag along is not dedupable based on only it's intrinsic properties.
two identical tags may need to be included and hoisted together with
preceding meta tags that describe a semantic object with a linear set of
html nodes.
It was clear that the concept of Browser Resources (stylesheets /
scripts / preloads) did not extend universally to all hositable tags
(title, meta, other links, etc...)
Additionally while Resources benefit from deduping they suffer an
inability to update because while we may have multiple rendered elements
that refer to a single Resource it isn't unambiguous which element owns
the props on the underlying resource. We could try merging props, but
that is still really hard to reason about for authors. Instead we
restrict Resource semantics to freezing the props at the time the
Resource is first constructed and warn if you attempt to render the same
Resource with different props via another rendered element or by
updating an existing element for that Resource.
This lack of updating restriction is however way more extreme than
necessary for instances that get hoisted but otherwise do not dedupe;
where there is a well defined DOM instance for each rendered element. We
should be able to update props on these instances.
Hoistable is a generalization of what Float tries to model for hoisting.
Instead of assuming every hoistable element is a Resource we now have
two distinct categories, hoistable elements and hoistable resources. As
one might guess the former has semantics that match regular Host
Components except the placement of the node is usually in the <head>.
The latter continues to behave how the original implementation of
HostResource behaved with the first iteration of Float
### Hoistable Element
On the server hoistable elements render just like regular tags except
the output is stored in special queues that can be emitted in the stream
earlier than they otherwise would be if rendered in place. This also
allow for instance the ability to render a hoistable before even
rendering the <html> tag because the queues for hoistable elements won't
flush until after we have flushed the preamble (`<DOCTYPE
html><html><head>`).
On the client, hoistable elements largely operate like HostComponents.
The most notable difference is in the hydration strategy. If we are
hydrating and encounter a hoistable element we will look for all tags in
the document that could potentially be a match and we check whether the
attributes match the props for this particular instance. We also do this
in the commit phase rather than the render phase. The reason hydration
can be done for HostComponents in render is the instance will be removed
from the document if hydration fails so mutating it in render is safe.
For hoistables the nodes are not in a hydration boundary (Root or
SuspenseBoundary at time of writing) and thus if hydration fails and we
may have an instance marked as bound to some Fiber when that Fiber never
commits. Moving the hydration matching to commit ensures we will always
succeed in pairing the hoisted DOM instance with a Fiber that has
committed.
### Hoistable Resource
On the server and client the semantics of Resources are largely the same
they just don't apply to title, meta, and most link tags anymore.
Resources hoist and dedupe via an `href` key and are ref counted. In a
future update we will add a garbage collector so we can clean up
Resources that no longer have any references
## `<style>` support
In earlier implementations there was no support for <style> tags. This
PR adds support for treating `<style href="..."
precedence="...">...</style>` as a Resource analagous to `<link
rel="stylesheet" href="..." precedence="..." />`
It may seem odd at first to require an href to get Resource semantics
for a style tag. The rationale is that these are for inlining of actual
external stylesheets as an optimization and for URI like scoping of
inline styles for css-in-js libraries. The href indicates that the key
space for `<style>` and `<link rel="stylesheet" />` Resources is shared.
and the precedence is there to allow for interleaving of both kinds of
Style resources. This is an advanced feature that we do not expect most
app developers to use directly but will be quite handy for various
styling libraries and for folks who want to inline as much as possible
once Fizz supports this feature.
## refactor notes
* HostResource Fiber type is renamed HostHoistable to reflect the
generalization of the concept
* The Resource object representation is modified to reduce hidden class
checks and to use less memory overall
* The thing that distinguishes a resource from an element is whether the
Fiber has a memoizedState. If it does, it will use resource semantics,
otherwise element semantics
* The time complexity of matching hositable elements for hydration
should be improved
