[compiler][poc] Quick experiment with SSR-optimization pass by josephsavona · Pull Request #35102 · react/react

josephsavona · 2025-11-11T02:59:50Z

Just a quick poc:

Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already.
Prune effects
Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow useRef() calls to be dropped since function calls aren't normally eligible for dropping.
Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves.

Per the fixture, this gets pretty far.

Stack created with Sapling. Best reviewed with ReviewStack.

josephsavona · 2025-11-11T03:06:50Z

+ setState(e.target.value);
+ };
+ useEffect(() => {
+ log(ref.current.value);


This is where the compiler machinery helps: the ref is referenced here, but DCE runs in a fixpoint. By pruning the effect call that makes its callback dead code, which then removes this reference to the ref. Then the OptimizeForSSR pass has already pruned the ref prop, so we're able to remove the useRef.

josephsavona · 2025-11-11T03:21:58Z

Another thing to add: for custom components we don't know for sure which callbacks are event handlers and which are render props. As implemented that means a lot of event/effect functions can't be pruned. But if we disallow setState during initial mount, then we know that any function which calls setState must be an event handler/effect. Similar for anything that calls startTransition. That should allow identifying a decent percentage of callbacks, though probably still far from all of them.

edit: done

mofeiZ

Exciting!

mofeiZ · 2025-11-20T22:02:54Z

But if we disallow setState during initial mount, then we know that any function which calls setState must be an event handler/effect. Similar for anything that calls startTransition. That should allow identifying a decent percentage of callbacks, though probably still far from all of them.

I'm sure you've already considered this, but it might be a pain to debug if we compile / replace these functions with a no-op -- but they actually get used during render

josephsavona · 2025-11-20T22:06:48Z

Yeah fair, we could do a follow-up where we replace with a simple function that throws if called.

Just a quick poc: * Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already. * Prune effects * Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow `useRef()` calls to be dropped since function calls aren't normally eligible for dropping. * Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves. Per the fixture, this gets pretty far.

Just a quick poc: * Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already. * Prune effects * Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow `useRef()` calls to be dropped since function calls aren't normally eligible for dropping. * Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves. Per the fixture, this gets pretty far. --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/react/pull/35102). * #35112 * __->__ #35102 DiffTrain build for [4cf770d](4cf770d)

josephsavona · 2025-11-11T02:59:50Z

Just a quick poc:

Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already.
Prune effects
Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow useRef() calls to be dropped since function calls aren't normally eligible for dropping.
Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves.

Per the fixture, this gets pretty far.

Stack created with Sapling. Best reviewed with ReviewStack.

josephsavona · 2025-11-11T03:06:50Z

+ setState(e.target.value);
+ };
+ useEffect(() => {
+ log(ref.current.value);


This is where the compiler machinery helps: the ref is referenced here, but DCE runs in a fixpoint. By pruning the effect call that makes its callback dead code, which then removes this reference to the ref. Then the OptimizeForSSR pass has already pruned the ref prop, so we're able to remove the useRef.

josephsavona · 2025-11-11T03:21:58Z

Another thing to add: for custom components we don't know for sure which callbacks are event handlers and which are render props. As implemented that means a lot of event/effect functions can't be pruned. But if we disallow setState during initial mount, then we know that any function which calls setState must be an event handler/effect. Similar for anything that calls startTransition. That should allow identifying a decent percentage of callbacks, though probably still far from all of them.

edit: done

mofeiZ

Exciting!

mofeiZ · 2025-11-20T22:02:54Z

But if we disallow setState during initial mount, then we know that any function which calls setState must be an event handler/effect. Similar for anything that calls startTransition. That should allow identifying a decent percentage of callbacks, though probably still far from all of them.

I'm sure you've already considered this, but it might be a pain to debug if we compile / replace these functions with a no-op -- but they actually get used during render

josephsavona · 2025-11-20T22:06:48Z

Yeah fair, we could do a follow-up where we replace with a simple function that throws if called.

Just a quick poc: * Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already. * Prune effects * Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow `useRef()` calls to be dropped since function calls aren't normally eligible for dropping. * Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves. Per the fixture, this gets pretty far.

Just a quick poc: * Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already. * Prune effects * Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow `useRef()` calls to be dropped since function calls aren't normally eligible for dropping. * Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves. Per the fixture, this gets pretty far. --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/react/pull/35102). * #35112 * __->__ #35102 DiffTrain build for [4cf770d](4cf770d)

josephsavona · 2025-11-11T02:59:50Z

Just a quick poc:

Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already.
Prune effects
Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow useRef() calls to be dropped since function calls aren't normally eligible for dropping.
Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves.

Per the fixture, this gets pretty far.

Stack created with Sapling. Best reviewed with ReviewStack.

josephsavona · 2025-11-11T03:06:50Z

+ setState(e.target.value);
+ };
+ useEffect(() => {
+ log(ref.current.value);


This is where the compiler machinery helps: the ref is referenced here, but DCE runs in a fixpoint. By pruning the effect call that makes its callback dead code, which then removes this reference to the ref. Then the OptimizeForSSR pass has already pruned the ref prop, so we're able to remove the useRef.

josephsavona · 2025-11-11T03:21:58Z

Another thing to add: for custom components we don't know for sure which callbacks are event handlers and which are render props. As implemented that means a lot of event/effect functions can't be pruned. But if we disallow setState during initial mount, then we know that any function which calls setState must be an event handler/effect. Similar for anything that calls startTransition. That should allow identifying a decent percentage of callbacks, though probably still far from all of them.

edit: done

mofeiZ

Exciting!

mofeiZ · 2025-11-20T22:02:54Z

But if we disallow setState during initial mount, then we know that any function which calls setState must be an event handler/effect. Similar for anything that calls startTransition. That should allow identifying a decent percentage of callbacks, though probably still far from all of them.

I'm sure you've already considered this, but it might be a pain to debug if we compile / replace these functions with a no-op -- but they actually get used during render

josephsavona · 2025-11-20T22:06:48Z

Yeah fair, we could do a follow-up where we replace with a simple function that throws if called.

Just a quick poc: * Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already. * Prune effects * Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow `useRef()` calls to be dropped since function calls aren't normally eligible for dropping. * Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves. Per the fixture, this gets pretty far.

Just a quick poc: * Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already. * Prune effects * Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow `useRef()` calls to be dropped since function calls aren't normally eligible for dropping. * Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves. Per the fixture, this gets pretty far. --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/react/pull/35102). * #35112 * __->__ #35102 DiffTrain build for [4cf770d](4cf770d)

josephsavona · 2025-11-11T02:59:50Z

Just a quick poc:

Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already.
Prune effects
Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow useRef() calls to be dropped since function calls aren't normally eligible for dropping.
Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves.

Per the fixture, this gets pretty far.

Stack created with Sapling. Best reviewed with ReviewStack.

josephsavona · 2025-11-11T03:06:50Z

+ setState(e.target.value);
+ };
+ useEffect(() => {
+ log(ref.current.value);


This is where the compiler machinery helps: the ref is referenced here, but DCE runs in a fixpoint. By pruning the effect call that makes its callback dead code, which then removes this reference to the ref. Then the OptimizeForSSR pass has already pruned the ref prop, so we're able to remove the useRef.

josephsavona · 2025-11-11T03:21:58Z

Another thing to add: for custom components we don't know for sure which callbacks are event handlers and which are render props. As implemented that means a lot of event/effect functions can't be pruned. But if we disallow setState during initial mount, then we know that any function which calls setState must be an event handler/effect. Similar for anything that calls startTransition. That should allow identifying a decent percentage of callbacks, though probably still far from all of them.

edit: done

mofeiZ

Exciting!

mofeiZ · 2025-11-20T22:02:54Z

But if we disallow setState during initial mount, then we know that any function which calls setState must be an event handler/effect. Similar for anything that calls startTransition. That should allow identifying a decent percentage of callbacks, though probably still far from all of them.

I'm sure you've already considered this, but it might be a pain to debug if we compile / replace these functions with a no-op -- but they actually get used during render

josephsavona · 2025-11-20T22:06:48Z

Yeah fair, we could do a follow-up where we replace with a simple function that throws if called.

Just a quick poc: * Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already. * Prune effects * Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow `useRef()` calls to be dropped since function calls aren't normally eligible for dropping. * Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves. Per the fixture, this gets pretty far.

Just a quick poc: * Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already. * Prune effects * Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow `useRef()` calls to be dropped since function calls aren't normally eligible for dropping. * Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves. Per the fixture, this gets pretty far. --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/react/pull/35102). * #35112 * __->__ #35102 DiffTrain build for [4cf770d](4cf770d)

josephsavona · 2025-11-11T02:59:50Z

Just a quick poc:

Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already.
Prune effects
Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow useRef() calls to be dropped since function calls aren't normally eligible for dropping.
Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves.

Per the fixture, this gets pretty far.

Stack created with Sapling. Best reviewed with ReviewStack.

josephsavona · 2025-11-11T03:06:50Z

+ setState(e.target.value);
+ };
+ useEffect(() => {
+ log(ref.current.value);


This is where the compiler machinery helps: the ref is referenced here, but DCE runs in a fixpoint. By pruning the effect call that makes its callback dead code, which then removes this reference to the ref. Then the OptimizeForSSR pass has already pruned the ref prop, so we're able to remove the useRef.

josephsavona · 2025-11-11T03:21:58Z

Another thing to add: for custom components we don't know for sure which callbacks are event handlers and which are render props. As implemented that means a lot of event/effect functions can't be pruned. But if we disallow setState during initial mount, then we know that any function which calls setState must be an event handler/effect. Similar for anything that calls startTransition. That should allow identifying a decent percentage of callbacks, though probably still far from all of them.

edit: done

mofeiZ

Exciting!

mofeiZ · 2025-11-20T22:02:54Z

But if we disallow setState during initial mount, then we know that any function which calls setState must be an event handler/effect. Similar for anything that calls startTransition. That should allow identifying a decent percentage of callbacks, though probably still far from all of them.

I'm sure you've already considered this, but it might be a pain to debug if we compile / replace these functions with a no-op -- but they actually get used during render

josephsavona · 2025-11-20T22:06:48Z

Yeah fair, we could do a follow-up where we replace with a simple function that throws if called.

Just a quick poc: * Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already. * Prune effects * Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow `useRef()` calls to be dropped since function calls aren't normally eligible for dropping. * Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves. Per the fixture, this gets pretty far.

Just a quick poc: * Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already. * Prune effects * Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow `useRef()` calls to be dropped since function calls aren't normally eligible for dropping. * Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves. Per the fixture, this gets pretty far. --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/react/pull/35102). * #35112 * __->__ #35102 DiffTrain build for [4cf770d](4cf770d)

josephsavona · 2025-11-11T02:59:50Z

Just a quick poc:

Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already.
Prune effects
Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow useRef() calls to be dropped since function calls aren't normally eligible for dropping.
Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves.

Per the fixture, this gets pretty far.

Stack created with Sapling. Best reviewed with ReviewStack.

josephsavona · 2025-11-11T03:06:50Z

+ setState(e.target.value);
+ };
+ useEffect(() => {
+ log(ref.current.value);


This is where the compiler machinery helps: the ref is referenced here, but DCE runs in a fixpoint. By pruning the effect call that makes its callback dead code, which then removes this reference to the ref. Then the OptimizeForSSR pass has already pruned the ref prop, so we're able to remove the useRef.

josephsavona · 2025-11-11T03:21:58Z

Another thing to add: for custom components we don't know for sure which callbacks are event handlers and which are render props. As implemented that means a lot of event/effect functions can't be pruned. But if we disallow setState during initial mount, then we know that any function which calls setState must be an event handler/effect. Similar for anything that calls startTransition. That should allow identifying a decent percentage of callbacks, though probably still far from all of them.

edit: done

mofeiZ

Exciting!

mofeiZ · 2025-11-20T22:02:54Z

But if we disallow setState during initial mount, then we know that any function which calls setState must be an event handler/effect. Similar for anything that calls startTransition. That should allow identifying a decent percentage of callbacks, though probably still far from all of them.

I'm sure you've already considered this, but it might be a pain to debug if we compile / replace these functions with a no-op -- but they actually get used during render

josephsavona · 2025-11-20T22:06:48Z

Yeah fair, we could do a follow-up where we replace with a simple function that throws if called.

Just a quick poc: * Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already. * Prune effects * Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow `useRef()` calls to be dropped since function calls aren't normally eligible for dropping. * Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves. Per the fixture, this gets pretty far.

Just a quick poc: * Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already. * Prune effects * Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow `useRef()` calls to be dropped since function calls aren't normally eligible for dropping. * Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves. Per the fixture, this gets pretty far. --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/react/pull/35102). * #35112 * __->__ #35102 DiffTrain build for [4cf770d](4cf770d)

josephsavona · 2025-11-11T02:59:50Z

Just a quick poc:

Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already.
Prune effects
Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow useRef() calls to be dropped since function calls aren't normally eligible for dropping.
Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves.

Per the fixture, this gets pretty far.

Stack created with Sapling. Best reviewed with ReviewStack.

josephsavona · 2025-11-11T03:06:50Z

+ setState(e.target.value);
+ };
+ useEffect(() => {
+ log(ref.current.value);


This is where the compiler machinery helps: the ref is referenced here, but DCE runs in a fixpoint. By pruning the effect call that makes its callback dead code, which then removes this reference to the ref. Then the OptimizeForSSR pass has already pruned the ref prop, so we're able to remove the useRef.

josephsavona · 2025-11-11T03:21:58Z

Another thing to add: for custom components we don't know for sure which callbacks are event handlers and which are render props. As implemented that means a lot of event/effect functions can't be pruned. But if we disallow setState during initial mount, then we know that any function which calls setState must be an event handler/effect. Similar for anything that calls startTransition. That should allow identifying a decent percentage of callbacks, though probably still far from all of them.

edit: done

mofeiZ

Exciting!

mofeiZ · 2025-11-20T22:02:54Z

But if we disallow setState during initial mount, then we know that any function which calls setState must be an event handler/effect. Similar for anything that calls startTransition. That should allow identifying a decent percentage of callbacks, though probably still far from all of them.

I'm sure you've already considered this, but it might be a pain to debug if we compile / replace these functions with a no-op -- but they actually get used during render

josephsavona · 2025-11-20T22:06:48Z

Yeah fair, we could do a follow-up where we replace with a simple function that throws if called.

Just a quick poc: * Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already. * Prune effects * Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow `useRef()` calls to be dropped since function calls aren't normally eligible for dropping. * Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves. Per the fixture, this gets pretty far.

Just a quick poc: * Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already. * Prune effects * Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow `useRef()` calls to be dropped since function calls aren't normally eligible for dropping. * Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves. Per the fixture, this gets pretty far. --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/react/pull/35102). * #35112 * __->__ #35102 DiffTrain build for [4cf770d](4cf770d)

josephsavona · 2025-11-11T02:59:50Z

Just a quick poc:

Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already.
Prune effects
Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow useRef() calls to be dropped since function calls aren't normally eligible for dropping.
Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves.

Per the fixture, this gets pretty far.

Stack created with Sapling. Best reviewed with ReviewStack.

josephsavona · 2025-11-11T03:06:50Z

+ setState(e.target.value);
+ };
+ useEffect(() => {
+ log(ref.current.value);


This is where the compiler machinery helps: the ref is referenced here, but DCE runs in a fixpoint. By pruning the effect call that makes its callback dead code, which then removes this reference to the ref. Then the OptimizeForSSR pass has already pruned the ref prop, so we're able to remove the useRef.

josephsavona · 2025-11-11T03:21:58Z

Another thing to add: for custom components we don't know for sure which callbacks are event handlers and which are render props. As implemented that means a lot of event/effect functions can't be pruned. But if we disallow setState during initial mount, then we know that any function which calls setState must be an event handler/effect. Similar for anything that calls startTransition. That should allow identifying a decent percentage of callbacks, though probably still far from all of them.

edit: done

mofeiZ

Exciting!

mofeiZ · 2025-11-20T22:02:54Z

But if we disallow setState during initial mount, then we know that any function which calls setState must be an event handler/effect. Similar for anything that calls startTransition. That should allow identifying a decent percentage of callbacks, though probably still far from all of them.

I'm sure you've already considered this, but it might be a pain to debug if we compile / replace these functions with a no-op -- but they actually get used during render

josephsavona · 2025-11-20T22:06:48Z

Yeah fair, we could do a follow-up where we replace with a simple function that throws if called.

Just a quick poc: * Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already. * Prune effects * Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow `useRef()` calls to be dropped since function calls aren't normally eligible for dropping. * Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves. Per the fixture, this gets pretty far.

Just a quick poc: * Inline useState when the initializer is known to not be a function. The heuristic could be improved but will handle a large number of cases already. * Prune effects * Prune useRef if the ref is unused, by pruning 'ref' props on primitive components. Then DCE does the rest of the work - with a small change to allow `useRef()` calls to be dropped since function calls aren't normally eligible for dropping. * Prune event handlers, by pruning props whose names start w "on" from primitive components. Then DCE removes the functions themselves. Per the fixture, this gets pretty far. --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/react/pull/35102). * #35112 * __->__ #35102 DiffTrain build for [4cf770d](4cf770d)

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github-actionsBot added the React Core Team Opened by a member of the React Core Team label Nov 11, 2025

josephsavona force-pushed the pr35102 branch from 84c1d4b to 9d5ceb9Compare November 11, 2025 03:02

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[compiler] Deprecate noEmit, add outputMode #35112
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josephsavona marked this pull request as ready for review November 14, 2025 16:46

mofeiZ approved these changes Nov 20, 2025
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josephsavona force-pushed the pr35102 branch from 5fa5200 to ab6d14bCompare November 20, 2025 22:53

josephsavona merged commit 4cf770d into mainNov 20, 2025
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Upgrade React from 8ac5f4eb-20251119 to 40b4a5bf-20251120vercel/next.js#86388
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Upgrade React from 8ac5f4eb-20251119 to fd524fe0-20251121vercel/next.js#86473
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