29 Commits

Author SHA1 Message Date
Sebastian Markbåge a083344699 [DevTools] Compute environment names for the timeline (#34892)
Stacked on #34885.

This refactors the timeline to store not just an id but a complex object
for each step. This will later represent a group of boundaries.

Each timeline step is assigned an environment name. We pick the last
environment name (assumed to have resolved last) from the union of the
parent and child environment names. I.e. a child step is considered to
be blocked by the parent so if a child isn't blocked on any environment
name it still gets marked as the parent's environment name.

In a follow up, I'd like to reorder the document order timeline based on
environment names to favor loading everything in one environment before
the next.
2025-10-17 18:54:53 -04:00
Sebastian Markbåge 6773248311 [DevTools] Track whether a boundary is currently suspended and make transparent (#34853)
This makes the rects that are currently in a suspended state appear
ghostly so that you can see where along the timeline you are in the
rects screen.

<img width="451" height="407" alt="Screenshot 2025-10-14 at 11 43 20 PM"
src="https://github.com/user-attachments/assets/f89e362b-a0d5-46e3-8171-564909715cd1"
/>
2025-10-15 10:26:07 -04:00
Sebastian "Sebbie" Silbermann b1c519f3d4 [DevTools] Only show boundaries with unique suspenders by default in the timeline (#34397) 2025-09-11 11:33:05 +02:00
Sebastian Markbåge 42b1b33a24 [DevTools] Add byteSize field to ReactIOInfo and show this in the tooltip (#34221)
This is intended to be used by various client side resources where the
transfer size is interesting to know how it'll perform in various
network conditions. Not intended to be added by the server.

For now it's only added internally by DevTools itself on img/css but
I'll add it from Flight Client too in a follow up.

This now shows this as the "transfer size" which is the encoded body
size + headers/overhead. Where as the "fileSize" that I add to images is
the decoded body size, like what you'd see on disk. This is what Chrome
shows so it's less confusing if you compare Network tab and this view.
2025-08-17 16:17:11 -04:00
Sebastian Markbåge 431bb0bddb [DevTools] Mark Unknown Reasons for Suspending with a Note (#34200)
We currently only track the reason something might suspend in
development mode through debug info but this excludes some cases. As a
result we can end up with boundary that suspends but has no cause. This
tries to detect that and show a notice for why that might be. I'm also
trying to make it work with old React versions to cover everything.

In production we don't track any of this meta data like `_debugInfo`,
`_debugThenable` etc. so after resolution there's no information to take
from. Except suspensey images / css which we can track in prod too. We
could track lazy component types already. We'd have to add something
that tracks after the fact if something used a lazy child, child as a
promise, hooks, etc. which doesn't exist today. So that's not backwards
compatible and might add some perf/memory cost. However, another
strategy is also to try to replay the components after the fact which
could be backwards compatible. That's tricky for child position since
there's so many rules for how to do that which would have to be
replicated.

If you're in development you get a different error. Given that we've
added instrumentation very recently. If you're on an older development
version of React, then you get a different error. Unfortunately I think
my feature test is not quite perfect because it's tricky to test for the
instrumentation I just added.
https://github.com/facebook/react/pull/34146 So I think for some
prereleases that has `_debugOwner` but doesn't have that you'll get a
misleading error.

Finally, if you're in a modern development environment, the only reason
we should have any gaps is because of throw-a-Promise. This will
highlight it as missing. We can detect that something threw if a
Suspense boundary commits with a RetryCache but since it's a WeakSet we
can't look into it to see anything about what it might have been. I
don't plan on doing anything to improve this since it would only apply
to new versions of React anyway and it's just inherently flawed. So just
deprecate it #34032.

Note that nothing in here can detect that we suspended Transition. So
throwing at the root or in an update won't show that anywhere.
2025-08-15 18:32:27 -04:00
Sebastian "Sebbie" Silbermann 2d98b45d92 [DevTools] Fix Suspense boundaries always being marked as not suspended (#34206) 2025-08-15 19:39:59 +02:00
Sebastian Markbåge 2ba7b07ce1 [DevTools] Compute a min and max range for the currently selected suspense boundary (#34201)
This computes a min and max range for the whole suspense boundary even
when selecting a single component so that each component in a boundary
has a consistent range.

The start of this range is the earliest start of I/O in that boundary or
the end of the previous suspense boundary, whatever is earlier. If the
end of the previous boundary would make the range large, then we cap it
since it's likely that the other boundary was just an independent
render.

The end of the range is the latest end of I/O in that boundary. If this
is smaller than the end of the previous boundary plus the 300ms
throttle, then we extend the end. This visualizes what throttling could
potentially do if the previous boundary committed right at its end. Ofc,
it might not have committed exactly at that time in this render. So this
is just showing a potential throttle that could happen. To see actual
throttle, you look in the Performance Track.

<img width="661" height="353" alt="Screenshot 2025-08-14 at 12 41 43 AM"
src="https://github.com/user-attachments/assets/b0155e5e-a83f-400c-a6b9-5c38a9d8a34f"
/>

We could come up with some annotation to highlight that this is eligible
to be throttled in this case. If the lines don't extend to the edge,
then it's likely it was throttled.
2025-08-15 13:34:07 -04:00
Sebastian "Sebbie" Silbermann de06211dbe [DevTools] Send Suspense rects to frontend (#34170) 2025-08-12 16:48:35 +02:00
Sebastian Markbåge ab5238d5a4 [DevTools] Show name prop of Suspense / Activity in the Components Tree view (#34135)
The name prop will be used in the Suspense tab to help identity a
boundary. Activity will also allow names. A custom component can be
identified by the name of the component but built-ins doesn't have that.

This PR adds it to the Components Tree View as well since otherwise you
only have the key to go on. Normally we don't add all the props to avoid
making this view too noisy but this is an exception along with key to
help identify a boundary quickly in the tree.

Unlike the SuspenseNode store, this wouldn't ever have a name inferred
by owner since that kind of context already exists in this view.

<img width="600" height="161" alt="Screenshot 2025-08-08 at 1 20 36 PM"
src="https://github.com/user-attachments/assets/fe50d624-887a-4b9d-9186-75f131f83195"
/>

I also made both the key and name prop searchable.

<img width="608" height="206" alt="Screenshot 2025-08-08 at 1 32 27 PM"
src="https://github.com/user-attachments/assets/d3502d9c-7614-45fc-b973-57f06dd9cddc"
/>
2025-08-11 11:41:46 -04:00
Sebastian Markbåge 7a934a16b8 [DevTools] Show Owner Stacks in "rendered by" View (#34130)
This shows the stack trace of the JSX at each level so now you can also
jump to the code location for the JSX callsite. The visual is similar to
the owner stacks with `createTask` except when you click the `<...>` you
jump to the Instance in the Components panel.

<img width="593" height="450" alt="Screenshot 2025-08-08 at 12 19 21 AM"
src="https://github.com/user-attachments/assets/dac35faf-9d99-46ce-8b41-7c6fe24625d2"
/>

I'm not sure it's really necessary to have all the JSX stacks of every
owner. We could just have it for the current component and then the rest
of the owners you could get to if you just click that owner instance.

As a bonus, I also use the JSX callsite as the fallback for the "View
Source" button. This is primarily useful for built-ins like `<div>` and
`<Suspense>` that don't have any implementation to jump to anyway. It's
useful to be able to jump to where a boundary was defined.
2025-08-11 11:41:30 -04:00
Sebastian "Sebbie" Silbermann 98286cf8e3 [DevTools] Send suspense nodes to frontend store (#34070) 2025-08-10 10:12:20 +02:00
Sebastian Markbåge 738aebdbac [DevTools] Add Badge to Owners and sometimes stack traces (#34106)
Stacked on #34101.

This adds a badge to owners if they are different from the currently
selected component's environment.

<img width="590" height="566" alt="Screenshot 2025-08-04 at 5 15 02 PM"
src="https://github.com/user-attachments/assets/e898254f-1b4c-498e-8713-978d90545340"
/>

We also add one to the end of stack traces if the stack trace has a
different environment than the owner which can happen when you call a
function (without rendering a component) into a third party environment
but the owner component was in the first party.

One awkward thing is that Suspense boundaries are always in the client
environment so their Server Components are always badged.
2025-08-07 10:39:08 -04:00
Sebastian Markbåge 71236c9409 [DevTools] Include the description derived from the promise (#34017)
Stacked on #34016.

This is using the same thing we already do for the performance track to
provide a description of the I/O based on the content of the resolved
Promise. E.g. a Response's URL.

<img width="375" height="388" alt="Screenshot 2025-07-28 at 1 09 49 AM"
src="https://github.com/user-attachments/assets/f3fdc40f-4e21-4e83-b49e-21c7ec975137"
/>
2025-07-28 15:11:04 -04:00
Sebastian Markbåge 4a58b63865 [DevTools] Add "suspended by" Section to Component Inspector Sidebar (#34012)
This collects the ReactAsyncInfo between instances. It associates it
with the parent. Typically this would be a Server Component's Promise
return value but it can also be Promises in a fragment. It can also be
associated with a client component when you pass a Promise into the
child position e.g. `<div>{promise}</div>` then it's associated with the
div. If an instance is filtered, then it gets associated with the parent
of that's unfiltered.

The stack trace currently isn't source mapped. I'll do that in a follow
up.

We also need to add a "short name" from the Promise for the description
(e.g. url). I'll also add a little marker showing the relative time span
of each entry.

<img width="447" height="591" alt="Screenshot 2025-07-26 at 7 56 00 PM"
src="https://github.com/user-attachments/assets/7c966540-7b1b-4568-8cb9-f25cefd5a918"
/>
<img width="446" height="570" alt="Screenshot 2025-07-26 at 7 55 23 PM"
src="https://github.com/user-attachments/assets/4eac235b-e735-41e8-9c6e-a7633af64e4b"
/>
2025-07-28 12:05:56 -04:00
Sebastian Markbåge 142fd27bf6 [DevTools] Add Option to Open Local Files directly in External Editor (#33983)
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.
2025-07-25 10:16:43 -04:00
Sebastian Markbåge 7513996f20 [DevTools] Unify by using ReactFunctionLocation type instead of Source (#33955)
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).
2025-07-22 10:53:08 -04:00
Ruslan Lesiutin f0c767e2a2 feat[devtools]: display native tag for host components for Native (#32762)
Native only. Displays the native tag for Native Host components inside a
badge, when user inspects the component.

Only displaying will be supported for now, because in order to get
native tags indexable, they should be part of the bridge operations,
which is technically a breaking change that requires significantly more
time investment.

The text will only be shown when user hovers over the badge.
![Screenshot 2025-03-26 at 19 46
40](https://github.com/user-attachments/assets/787530cf-c5e5-4b85-8e2a-15b006a3d783)
2025-04-02 22:44:38 +01:00
Ricky 1a191701fe [refactor] Add element type for Activity (#32499)
This PR separates Activity to it's own element type separate from
Offscreen. The goal is to allow us to add Activity element boundary
semantics during hydration similar to Suspense semantics, without
impacting the Offscreen behavior in suspended children.
2025-03-17 09:17:00 -04:00
Ruslan Lesiutin 221f3002ca chore[DevTools]: make clipboardWrite optional for chromium (#32262)
Addresses https://github.com/facebook/react/issues/32244.

### Chromium
We will use
[chrome.permissions](https://developer.chrome.com/docs/extensions/reference/api/permissions)
for checking / requesting `clipboardWrite` permission before copying
something to the clipboard.

### Firefox
We will keep `clipboardWrite` as a required permission, because there is
no reliable and working API for requesting optional permissions for
extensions that are extending browser DevTools:
- `chrome.permissions` is unavailable for devtools pages -
https://bugzilla.mozilla.org/show_bug.cgi?id=1796933
- You can't call `chrome.permissions.request` from background, because
this instruction has to be executed inside user-event callback,
basically only initiated by user.

I don't really want to come up with solutions like opening a new tab
with a button that user has to click.
2025-01-30 20:08:17 +00:00
Ruslan Lesiutin d2a1b8854d fix[DevTools/Tree]: only scroll to item when panel is visible (#32018)
Stacked on https://github.com/facebook/react/pull/31968. See commit on
top.

Fixes an issue with bank tree view, when we are scrolling to an item
while syncing user DOM selection. This should only have an effect on
browser extension. Added events with `extension` prefix will only be
emitted in browser extension implementation, for other implementations
`useExtensionComponentsPanelVisibility` will return constant `true`
value.

Before:


https://github.com/user-attachments/assets/82667c16-d495-4346-af0a-7ed22ff89cfc


After:


https://github.com/user-attachments/assets/a5d223fd-0328-44f0-af68-5c3863f1efee
2025-01-09 18:38:49 +00:00
Sebastian Markbåge c4595ca4c8 Add ViewTransitionComponent to Stacks and DevTools (#32034)
Just adding the name so it shows up.

(Note that no experimental ones are added to the list of filters atm.
Including SuspenseList etc.)
2025-01-09 11:33:34 -05:00
Sebastian Markbåge a06cd9e1d1 [DevTools] Refactor Forcing Fallback / Error of Suspense / Error Boundaries (#30870)
First, this basically reverts
https://github.com/facebook/react/pull/30517/commits/1f3892ef8cc181218587ddc6accd994890c92ef5
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.
2024-09-05 15:48:17 -04:00
Sebastian Markbåge 04ec50efa9 [DevTools] Add Filtering of Environment Names (#30850)
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">
2024-09-03 12:29:15 -04:00
Sebastian Markbåge 49496d4937 [DevTools] Support Server Components in Tree (#30684)
This adds VirtualInstances to the tree. Each Fiber has a list of its
parent Server Components in `_debugInfo`. The algorithm is that when we
enter a set of fibers, we actually traverse level 0 of all the
`_debugInfo` in each fiber. Then level 1 of each `_debugInfo` and so on.
It would be simpler if `_debugInfo` only contained Server Component
since then we could just look at the index in the array but it actually
contains other data as well which leads to multiple passes but we don't
expect it to have a lot of levels before hitting a reified fiber.
Finally when we hit the end a traverse the fiber itself.

This lets us match consecutive `ReactComponentInfo` that are all the
same at the same level. This creates a single VirtualInstance for each
sequence. This lets the same Server Component instance that's a parent
to multiple children appear as a single Instance instead of one per
Fiber.

Since a Server Component's result can be rendered in more than one place
there's not a 1:1 mapping though. If it is in different parents or if
the sequence is interrupted, then it gets split into two different
instances with the same `ReactComponentInfo` data.

The real interesting case is what happens during updates because this
algorithm means that a Fiber can become reparented during an update to
end up in a different VirtualInstance. The ideal would maybe be that the
frontend could deal with this reparenting but instead I basically just
unmount the previous instance (and its children) and mount a new
instance which leads to some interesting scenarios. This is inline with
the strategy I was intending to pursue anyway where instances are
reconciled against the previous children of the same parent instead of
the `fiberToFiberInstance` map - which would let us get rid of that map.
In that case the model is resilient to Fiber being in more than one
place at a time.

However this unmount/remount does mean that we can lose selection when
this happens. We could maybe do something like using the tracked path
like I did for component filters. Ideally it's a weird edge case though
because you'd typically not have it. The main case that it happens now
is for reorders of list of server components. In that case basically all
the children move between server components while the server components
themselves stay in place. We should really include the key in server
components so that we can reconcile them using the key to handle
reorders which would solve the common case anyway.

I convert the name to the `Env(Name)` pattern which allows the
Environment Name to be used as a badge.

<img width="1105" alt="Screenshot 2024-08-13 at 9 55 29 PM"
src="https://github.com/user-attachments/assets/323c20ba-b655-4ee8-84fa-8233f55d2999">

(Screenshot is with #30667. I haven't tried it with the alternative
fix.)

---------

Co-authored-by: Ruslan Lesiutin <rdlesyutin@gmail.com>
2024-08-14 11:16:51 -04:00
Sebastian Markbåge ec98d36c3a [DevTools] Rename Fiber to Element in the Bridge Protocol and RendererInterface (#30490)
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.
2024-07-29 14:29:52 -04:00
Ruslan Lesiutin 61bd00498d refactor[devtools]: lazily define source for fiber based on component stacks (#28351)
`_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.
2024-03-05 12:10:36 +00:00
Sebastian Markbåge 37d901e2b8 Remove __self and __source location from elements (#28265)
Along with all the places using it like the `_debugSource` on Fiber.
This still lets them be passed into `createElement` (and JSX dev
runtime) since those can still be used in existing already compiled code
and we don't want that to start spreading to DOM attributes.

We used to have a DEV mode that compiles the source location of JSX into
the compiled output. This was nice because we could get the actual call
site of the JSX (instead of just somewhere in the component). It had a
bunch of issues though:

- It only works with JSX.
- The way this source location is compiled is different in all the
pipelines along the way. It relies on this transform being first and the
source location we want to extract but it doesn't get preserved along
source maps and don't have a way to be connected to the source hosted by
the source maps. Ideally it should just use the mechanism other source
maps use.
- Since it's expensive it only works in DEV so if it's used for
component stacks it would vary between dev and prod.
- It only captures the callsite of the JSX and not the stack between the
component and that callsite. In the happy case it's in the component but
not always.

Instead, we have another zero-cost trick to extract the call site of
each component lazily only if it's needed. This ensures that component
stacks are the same in DEV and PROD. At the cost of worse line number
information.

The better way to get the JSX call site would be to get it from `new
Error()` or `console.createTask()` inside the JSX runtime which can
capture the whole stack in a consistent way with other source mappings.
We might explore that in the future.

This removes source location info from React DevTools and React Native
Inspector. The "jump to source code" feature or inspection can be made
lazy instead by invoking the lazy component stack frame generation. That
way it can be made to work in prod too. The filtering based on file path
is a bit trickier.

When redesigned this UI should ideally also account for more than one
stack frame.

With this change the DEV only Babel transforms are effectively
deprecated since they're not necessary for anything.
2024-02-07 16:38:00 -05:00
Ruslan Lesiutin 6c7b41da3d feat[devtools]: display Forget badge for the relevant components (#27709)
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.
2023-11-23 18:37:21 +00:00
Ruslan Lesiutin 77ec61885f fix[devtools/inspectElement]: dont pause initial inspectElement call when user switches tabs (#27488)
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.


https://github.com/hoxyq/react/blob/af8beeebf63b5824497fcd0bb35b7c0ac8fe60a0/packages/react-devtools-shared/src/backendAPI.js#L96
2023-10-10 18:10:17 +01:00