From 0ca9d2077245a026f3b1430cede786a69d312434 Mon Sep 17 00:00:00 2001
From: lauren <poteto@users.noreply.github.com>
Date: Wed, 17 Jun 2026 15:54:14 -0700
Subject: [PATCH 1/2] [compiler] Count loop reassignments as the enclosing
 scope reassigning the variable (#36732)

A counter initialized before a memo scope and incremented inside it
(`a++` or `a = a + 1` in a `for` body) was emitted as a scope
*dependency*, compared at its pre-loop value (constant every render)
while the cache stored its post-loop value. The memo could never hit, so
the scope recomputed on every render.

Root cause: the phi-union rule in
`InferReactiveScopeVariables.findDisjointMutableValues` only unioned a
phi into the scope when the phi value was mutated after creation, which
range-extension only does for object mutation. Primitive reassignments
around a loop back-edge never extend ranges, so the counter's SSA
versions stayed outside the scope and downstream dependency propagation
classified the pre-loop read as a dep.

The fix unions a phi with its operands and declaration when any operand
is defined at or after the phi's block, i.e. the value is reassigned
around a loop back-edge. This matches the shape the compiler already
produced for non-primitive loop reassignment (`x = [...x, i]`).
Implemented identically in the TypeScript compiler and the Rust port.

Both `a++` and `a = a + 1` variants are pinned by fixtures; the first
commit documents the previously-wrong codegen, the second fixes it
(counter becomes a scope output, dep on `count` only).

Corpus delta beyond the new fixtures is 4 fixtures, all strict
improvements with byte-identical eval output: `for-in-statement-break`,
`for-in-statement-continue`, `for-in-statement-type-inference` (loops
previously re-ran every render, now memoized), and `sequence-expression`
(two memo blocks collapse into one).

Known limitation, unchanged from before: conditional reassignment in a
loop (`for (...) { if (c) a++; }`) routes through a join phi that this
rule cannot see; that shape behaves as it did before this change.

Verification: TS snap 1806/1806, Rust snap 1806/1806, cargo workspace
green, scoped TS-vs-Rust HIR parity harness green.

Closes #34971
---
 .../src/infer_reactive_scope_variables.rs     | 21 ++++++-
 .../InferReactiveScopeVariables.ts            | 29 +++++++--
 .../compiler/for-in-statement-break.expect.md | 22 +++----
 .../for-in-statement-continue.expect.md       | 22 +++----
 .../for-in-statement-type-inference.expect.md | 15 +++--
 ...p-counter-memoization-assignment.expect.md | 62 +++++++++++++++++++
 ...for-loop-counter-memoization-assignment.js | 17 +++++
 .../for-loop-counter-memoization.expect.md    | 62 +++++++++++++++++++
 .../compiler/for-loop-counter-memoization.js  | 17 +++++
 .../compiler/sequence-expression.expect.md    | 16 ++---
 10 files changed, 238 insertions(+), 45 deletions(-)
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-loop-counter-memoization-assignment.expect.md
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-loop-counter-memoization-assignment.js
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-loop-counter-memoization.expect.md
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-loop-counter-memoization.js

diff --git a/compiler/crates/react_compiler_inference/src/infer_reactive_scope_variables.rs b/compiler/crates/react_compiler_inference/src/infer_reactive_scope_variables.rs
index a64c73e91411..8847f21214b5 100644
--- a/compiler/crates/react_compiler_inference/src/infer_reactive_scope_variables.rs
+++ b/compiler/crates/react_compiler_inference/src/infer_reactive_scope_variables.rs
@@ -284,7 +284,26 @@ pub(crate) fn find_disjoint_mutable_values(
                 .map(|iid| func.instructions[iid.0 as usize].id)
                 .unwrap_or(block.terminal.evaluation_order());
 
-            if phi_range.start.0 + 1 != phi_range.end.0 && phi_range.end > first_instr_id {
+            let is_phi_mutated_after_creation = phi_range.start.0 + 1 != phi_range.end.0
+                && phi_range.end > first_instr_id;
+            // A phi operand defined at or after the phi's block is a loop
+            // back-edge: the variable is reassigned within the loop (eg a
+            // counter `a++` or `a = a + 1`). The reassignment must count as
+            // the loop's scope reassigning the variable, so union the phi
+            // with its operands and declaration. Otherwise the variable's
+            // pre-loop value would become a dependency of the scope even
+            // though the scope changes the value as it executes, making the
+            // scope's dependencies unstable (the cached dependency would be
+            // the post-loop value, which can never match the pre-loop value
+            // compared at the top of the scope).
+            let is_loop_carried_reassignment = !is_phi_mutated_after_creation
+                && phi.operands.iter().any(|(_pred_id, operand)| {
+                    env.identifiers[operand.identifier.0 as usize]
+                        .mutable_range
+                        .start
+                        >= first_instr_id
+                });
+            if is_phi_mutated_after_creation || is_loop_carried_reassignment {
                 let mut operands = vec![phi_id];
                 if let Some(&decl_id) = declarations.get(&phi_decl_id) {
                     operands.push(decl_id);
diff --git a/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/InferReactiveScopeVariables.ts b/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/InferReactiveScopeVariables.ts
index cbc973efa8d1..7585130c40a4 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/InferReactiveScopeVariables.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/InferReactiveScopeVariables.ts
@@ -25,7 +25,7 @@ import {
   eachPatternOperand,
 } from '../HIR/visitors';
 import DisjointSet from '../Utils/DisjointSet';
-import {assertExhaustive} from '../Utils/utils';
+import {Iterable_some, assertExhaustive} from '../Utils/utils';
 
 /*
  * Note: this is the 1st of 4 passes that determine how to break a function into discrete
@@ -287,12 +287,31 @@ export function findDisjointMutableValues(
      * are assigned to the same scope.
      */
     for (const phi of block.phis) {
-      if (
+      const firstInstructionIdOfBlock =
+        block.instructions.at(0)?.id ?? block.terminal.id;
+      const isPhiMutatedAfterCreation =
         phi.place.identifier.mutableRange.start + 1 !==
           phi.place.identifier.mutableRange.end &&
-        phi.place.identifier.mutableRange.end >
-          (block.instructions.at(0)?.id ?? block.terminal.id)
-      ) {
+        phi.place.identifier.mutableRange.end > firstInstructionIdOfBlock;
+      /*
+       * A phi operand defined at or after the phi's block is a loop back-edge:
+       * the variable is reassigned within the loop (eg a counter `a++` or
+       * `a = a + 1`). The reassignment must count as the loop's scope
+       * reassigning the variable, so union the phi with its operands and
+       * declaration. Otherwise the variable's pre-loop value would become a
+       * dependency of the scope even though the scope changes the value as it
+       * executes, making the scope's dependencies unstable (the cached
+       * dependency would be the post-loop value, which can never match the
+       * pre-loop value compared at the top of the scope).
+       */
+      const isLoopCarriedReassignment =
+        !isPhiMutatedAfterCreation &&
+        Iterable_some(
+          phi.operands.values(),
+          operand =>
+            operand.identifier.mutableRange.start >= firstInstructionIdOfBlock,
+        );
+      if (isPhiMutatedAfterCreation || isLoopCarriedReassignment) {
         const operands = [phi.place.identifier];
         const declaration = declarations.get(
           phi.place.identifier.declarationId,
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-in-statement-break.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-in-statement-break.expect.md
index a9d20954d00b..7c2d1164ca3c 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-in-statement-break.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-in-statement-break.expect.md
@@ -29,21 +29,19 @@ import { c as _c } from "react/compiler-runtime";
 function Component(props) {
   const $ = _c(2);
   let x;
-  let t0;
   if ($[0] !== props.value) {
-    t0 = { ...props.value };
+    const object = { ...props.value };
+    for (const y in object) {
+      if (y === "break") {
+        break;
+      }
+
+      x = object[y];
+    }
     $[0] = props.value;
-    $[1] = t0;
+    $[1] = x;
   } else {
-    t0 = $[1];
-  }
-  const object = t0;
-  for (const y in object) {
-    if (y === "break") {
-      break;
-    }
-
-    x = object[y];
+    x = $[1];
   }
 
   return x;
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-in-statement-continue.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-in-statement-continue.expect.md
index 06f13c05775a..2625b2b2bd1e 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-in-statement-continue.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-in-statement-continue.expect.md
@@ -38,21 +38,19 @@ import { c as _c } from "react/compiler-runtime";
 function Component(props) {
   const $ = _c(2);
   let x;
-  let t0;
   if ($[0] !== props.value) {
-    t0 = { ...props.value };
+    const object = { ...props.value };
+    for (const y in object) {
+      if (y === "continue") {
+        continue;
+      }
+
+      x = object[y];
+    }
     $[0] = props.value;
-    $[1] = t0;
+    $[1] = x;
   } else {
-    t0 = $[1];
-  }
-  const object = t0;
-  for (const y in object) {
-    if (y === "continue") {
-      continue;
-    }
-
-    x = object[y];
+    x = $[1];
   }
 
   return x;
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-in-statement-type-inference.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-in-statement-type-inference.expect.md
index 686d95a6f504..e9f0f74eac88 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-in-statement-type-inference.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-in-statement-type-inference.expect.md
@@ -25,14 +25,21 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code
 
 ```javascript
-// @enablePreserveExistingMemoizationGuarantees:false
+import { c as _c } from "react/compiler-runtime"; // @enablePreserveExistingMemoizationGuarantees:false
 const { identity, mutate } = require("shared-runtime");
 
 function Component(props) {
+  const $ = _c(2);
   let x;
-  const object = { ...props.value };
-  for (const y in object) {
-    x = y;
+  if ($[0] !== props.value) {
+    const object = { ...props.value };
+    for (const y in object) {
+      x = y;
+    }
+    $[0] = props.value;
+    $[1] = x;
+  } else {
+    x = $[1];
   }
 
   mutate(x);
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-loop-counter-memoization-assignment.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-loop-counter-memoization-assignment.expect.md
new file mode 100644
index 000000000000..10a399c0ef34
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-loop-counter-memoization-assignment.expect.md
@@ -0,0 +1,62 @@
+
+## Input
+
+```javascript
+import {Stringify} from 'shared-runtime';
+
+function Component({count}) {
+  let a = 0;
+  const items = [];
+  for (let i = 0; i < count; i++) {
+    a = a + 1;
+    items.push(a);
+  }
+  return <Stringify items={items} a={a} />;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{count: 2}],
+  sequentialRenders: [{count: 2}, {count: 2}, {count: 3}],
+};
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime";
+import { Stringify } from "shared-runtime";
+
+function Component(t0) {
+  const $ = _c(2);
+  const { count } = t0;
+  let t1;
+  if ($[0] !== count) {
+    let a = 0;
+    const items = [];
+    for (let i = 0; i < count; i++) {
+      a = a + 1;
+      items.push(a);
+    }
+    t1 = <Stringify items={items} a={a} />;
+    $[0] = count;
+    $[1] = t1;
+  } else {
+    t1 = $[1];
+  }
+  return t1;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{ count: 2 }],
+  sequentialRenders: [{ count: 2 }, { count: 2 }, { count: 3 }],
+};
+
+```
+      
+### Eval output
+(kind: ok) <div>{"items":[1,2],"a":2}</div>
+<div>{"items":[1,2],"a":2}</div>
+<div>{"items":[1,2,3],"a":3}</div>
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-loop-counter-memoization-assignment.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-loop-counter-memoization-assignment.js
new file mode 100644
index 000000000000..eed82622088f
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-loop-counter-memoization-assignment.js
@@ -0,0 +1,17 @@
+import {Stringify} from 'shared-runtime';
+
+function Component({count}) {
+  let a = 0;
+  const items = [];
+  for (let i = 0; i < count; i++) {
+    a = a + 1;
+    items.push(a);
+  }
+  return <Stringify items={items} a={a} />;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{count: 2}],
+  sequentialRenders: [{count: 2}, {count: 2}, {count: 3}],
+};
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-loop-counter-memoization.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-loop-counter-memoization.expect.md
new file mode 100644
index 000000000000..6bff9c3b18e5
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-loop-counter-memoization.expect.md
@@ -0,0 +1,62 @@
+
+## Input
+
+```javascript
+import {Stringify} from 'shared-runtime';
+
+function Component({count}) {
+  let a = 0;
+  const items = [];
+  for (let i = 0; i < count; i++) {
+    a++;
+    items.push(a);
+  }
+  return <Stringify items={items} a={a} />;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{count: 2}],
+  sequentialRenders: [{count: 2}, {count: 2}, {count: 3}],
+};
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime";
+import { Stringify } from "shared-runtime";
+
+function Component(t0) {
+  const $ = _c(2);
+  const { count } = t0;
+  let t1;
+  if ($[0] !== count) {
+    let a = 0;
+    const items = [];
+    for (let i = 0; i < count; i++) {
+      a++;
+      items.push(a);
+    }
+    t1 = <Stringify items={items} a={a} />;
+    $[0] = count;
+    $[1] = t1;
+  } else {
+    t1 = $[1];
+  }
+  return t1;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{ count: 2 }],
+  sequentialRenders: [{ count: 2 }, { count: 2 }, { count: 3 }],
+};
+
+```
+      
+### Eval output
+(kind: ok) <div>{"items":[1,2],"a":2}</div>
+<div>{"items":[1,2],"a":2}</div>
+<div>{"items":[1,2,3],"a":3}</div>
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-loop-counter-memoization.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-loop-counter-memoization.js
new file mode 100644
index 000000000000..687448dce693
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-loop-counter-memoization.js
@@ -0,0 +1,17 @@
+import {Stringify} from 'shared-runtime';
+
+function Component({count}) {
+  let a = 0;
+  const items = [];
+  for (let i = 0; i < count; i++) {
+    a++;
+    items.push(a);
+  }
+  return <Stringify items={items} a={a} />;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{count: 2}],
+  sequentialRenders: [{count: 2}, {count: 2}, {count: 3}],
+};
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/sequence-expression.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/sequence-expression.expect.md
index 3d06e2421d9b..1b85cd7b3dcf 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/sequence-expression.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/sequence-expression.expect.md
@@ -19,22 +19,16 @@ function foo() {}
 ```javascript
 import { c as _c } from "react/compiler-runtime";
 function sequence(props) {
-  const $ = _c(2);
-  let t0;
+  const $ = _c(1);
+  let x;
   if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
-    t0 = (Math.max(1, 2), foo());
-    $[0] = t0;
-  } else {
-    t0 = $[0];
-  }
-  let x = t0;
-  if ($[1] === Symbol.for("react.memo_cache_sentinel")) {
+    x = (Math.max(1, 2), foo());
     while ((foo(), true)) {
       x = (foo(), 2);
     }
-    $[1] = x;
+    $[0] = x;
   } else {
-    x = $[1];
+    x = $[0];
   }
 
   return x;

From 560db51408f4c186016ccdd8062af75a77c22104 Mon Sep 17 00:00:00 2001
From: Boshen <boshenc@gmail.com>
Date: Thu, 18 Jun 2026 07:07:24 +0800
Subject: [PATCH 2/2] [rust-compiler] Switch to hmac-sha256 and bump
 napi/similar (#36809)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

## Summary

Dependency maintenance for the Rust compiler crates.

### Fast Refresh hash: sha2 + hmac → hmac-sha256
The Fast Refresh source hash (`enableResetCacheOnSourceFileChanges`)
only needs an HMAC-SHA256 of the source text, matching the TS compiler's
`createHmac('sha256', code).digest('hex')`. RustCrypto's `sha2` + `hmac`
pulled in **11 crates** (`sha2`, `hmac`, `digest`, `block-buffer`,
`typenum`, `crypto-common`, `hybrid-array`, `const-oid`, `cpufeatures`,
`cmov`, `ctutils`) — generic-hashing / constant-time machinery that is
irrelevant for a non-security content fingerprint. This replaces them
with the single **zero-dependency** `hmac-sha256` crate: a net reduction
of **10 crates**.

HMAC-SHA256 is a standardized deterministic algorithm, so the emitted
hash is unchanged. A new unit test
`source_file_hash_matches_node_create_hmac` pins the result against
Node's `createHmac('sha256', code).digest('hex')` for several inputs.

### Other bumps
- `napi` / `napi-derive` 2 → 3
- `similar` 2 → 3 (dev-dependency)
- Drop the unused `react_compiler_lowering` dependency from
`react_compiler_ssa`

`cargo check --workspace --all-targets` passes, including the napi 3
native crate.
---
 compiler/Cargo.lock                           | 254 +++++++++---------
 compiler/crates/react_compiler_ast/Cargo.toml |   2 +-
 .../react_compiler_reactive_scopes/Cargo.toml |   3 +-
 .../src/codegen_reactive_function.rs          |  46 +++-
 compiler/crates/react_compiler_ssa/Cargo.toml |   1 -
 .../native/Cargo.toml                         |   4 +-
 6 files changed, 164 insertions(+), 146 deletions(-)

diff --git a/compiler/Cargo.lock b/compiler/Cargo.lock
index cd8be675a22b..9d6fa50b75c6 100644
--- a/compiler/Cargo.lock
+++ b/compiler/Cargo.lock
@@ -2,15 +2,6 @@
 # It is not intended for manual editing.
 version = 4
 
-[[package]]
-name = "aho-corasick"
-version = "1.1.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ddd31a130427c27518df266943a5308ed92d4b226cc639f5a8f1002816174301"
-dependencies = [
- "memchr",
-]
-
 [[package]]
 name = "bitflags"
 version = "2.11.0"
@@ -18,12 +9,13 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "843867be96c8daad0d758b57df9392b6d8d271134fce549de6ce169ff98a92af"
 
 [[package]]
-name = "block-buffer"
-version = "0.10.4"
+name = "bstr"
+version = "1.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3078c7629b62d3f0439517fa394996acacc5cbc91c5a20d8c658e77abd503a71"
+checksum = "63044e1ae8e69f3b5a92c736ca6269b8d12fa7efe39bf34ddb06d102cf0e2cab"
 dependencies = [
- "generic-array",
+ "memchr",
+ "serde",
 ]
 
 [[package]]
@@ -34,67 +26,117 @@ checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
 [[package]]
 name = "convert_case"
-version = "0.6.0"
+version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ec182b0ca2f35d8fc196cf3404988fd8b8c739a4d270ff118a398feb0cbec1ca"
+checksum = "affbf0190ed2caf063e3def54ff444b449371d55c58e513a95ab98eca50adb49"
 dependencies = [
  "unicode-segmentation",
 ]
 
 [[package]]
-name = "cpufeatures"
-version = "0.2.17"
+name = "ctor"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "400a21f1014a968ec518c7ccdf9b4a4ed0cac8c56ccb6d604f8b91f00110501e"
+
+[[package]]
+name = "ctor"
+version = "1.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "01334b89b69ff726750c5ce5073fc8bd860e99aa9a8fc5ca11b04730e3aee97a"
+
+[[package]]
+name = "equivalent"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
+
+[[package]]
+name = "futures"
+version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "59ed5838eebb26a2bb2e58f6d5b5316989ae9d08bab10e0e6d103e656d1b0280"
+checksum = "8b147ee9d1f6d097cef9ce628cd2ee62288d963e16fb287bd9286455b241382d"
 dependencies = [
- "libc",
+ "futures-channel",
+ "futures-core",
+ "futures-executor",
+ "futures-io",
+ "futures-sink",
+ "futures-task",
+ "futures-util",
 ]
 
 [[package]]
-name = "crypto-common"
-version = "0.1.7"
+name = "futures-channel"
+version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "78c8292055d1c1df0cce5d180393dc8cce0abec0a7102adb6c7b1eef6016d60a"
+checksum = "07bbe89c50d7a535e539b8c17bc0b49bdb77747034daa8087407d655f3f7cc1d"
 dependencies = [
- "generic-array",
- "typenum",
+ "futures-core",
+ "futures-sink",
 ]
 
 [[package]]
-name = "ctor"
-version = "0.2.9"
+name = "futures-core"
+version = "0.3.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7e3450815272ef58cec6d564423f6e755e25379b217b0bc688e295ba24df6b1d"
+
+[[package]]
+name = "futures-executor"
+version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32a2785755761f3ddc1492979ce1e48d2c00d09311c39e4466429188f3dd6501"
+checksum = "baf29c38818342a3b26b5b923639e7b1f4a61fc5e76102d4b1981c6dc7a7579d"
 dependencies = [
- "quote",
- "syn",
+ "futures-core",
+ "futures-task",
+ "futures-util",
 ]
 
 [[package]]
-name = "digest"
-version = "0.10.7"
+name = "futures-io"
+version = "0.3.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cecba35d7ad927e23624b22ad55235f2239cfa44fd10428eecbeba6d6a717718"
+
+[[package]]
+name = "futures-macro"
+version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9ed9a281f7bc9b7576e61468ba615a66a5c8cfdff42420a70aa82701a3b1e292"
+checksum = "e835b70203e41293343137df5c0664546da5745f82ec9b84d40be8336958447b"
 dependencies = [
- "block-buffer",
- "crypto-common",
- "subtle",
+ "proc-macro2",
+ "quote",
+ "syn",
 ]
 
 [[package]]
-name = "equivalent"
-version = "1.0.2"
+name = "futures-sink"
+version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
+checksum = "c39754e157331b013978ec91992bde1ac089843443c49cbc7f46150b0fad0893"
 
 [[package]]
-name = "generic-array"
-version = "0.14.7"
+name = "futures-task"
+version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "85649ca51fd72272d7821adaf274ad91c288277713d9c18820d8499a7ff69e9a"
+checksum = "037711b3d59c33004d3856fbdc83b99d4ff37a24768fa1be9ce3538a1cde4393"
+
+[[package]]
+name = "futures-util"
+version = "0.3.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "389ca41296e6190b48053de0321d02a77f32f8a5d2461dd38762c0593805c6d6"
 dependencies = [
- "typenum",
- "version_check",
+ "futures-channel",
+ "futures-core",
+ "futures-io",
+ "futures-macro",
+ "futures-sink",
+ "futures-task",
+ "memchr",
+ "pin-project-lite",
+ "slab",
 ]
 
 [[package]]
@@ -104,13 +146,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "841d1cc9bed7f9236f321df977030373f4a4163ae1a7dbfe1a51a2c1a51d9100"
 
 [[package]]
-name = "hmac"
-version = "0.12.1"
+name = "hmac-sha256"
+version = "1.1.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6c49c37c09c17a53d937dfbb742eb3a961d65a994e6bcdcf37e7399d0cc8ab5e"
-dependencies = [
- "digest",
-]
+checksum = "ec9d92d097f4749b64e8cc33d924d9f40a2d4eb91402b458014b781f5733d60f"
 
 [[package]]
 name = "indexmap"
@@ -130,17 +169,11 @@ version = "1.0.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "92ecc6618181def0457392ccd0ee51198e065e016d1d527a7ac1b6dc7c1f09d2"
 
-[[package]]
-name = "libc"
-version = "0.2.183"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b5b646652bf6661599e1da8901b3b9522896f01e736bad5f723fe7a3a27f899d"
-
 [[package]]
 name = "libloading"
-version = "0.8.9"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d7c4b02199fee7c5d21a5ae7d8cfa79a6ef5bb2fc834d6e9058e89c825efdc55"
+checksum = "754ca22de805bb5744484a5b151a9e1a8e837d5dc232c2d7d8c2e3492edc8b60"
 dependencies = [
  "cfg-if",
  "windows-link",
@@ -154,15 +187,17 @@ checksum = "f8ca58f447f06ed17d5fc4043ce1b10dd205e060fb3ce5b979b8ed8e59ff3f79"
 
 [[package]]
 name = "napi"
-version = "2.16.17"
+version = "3.8.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "55740c4ae1d8696773c78fdafd5d0e5fe9bc9f1b071c7ba493ba5c413a9184f3"
+checksum = "8e55037284865448ecf329baa86a4d05401f647ebde99f5747b640d32c2c5226"
 dependencies = [
  "bitflags",
- "ctor",
- "napi-derive",
+ "ctor 0.11.1",
+ "futures",
+ "napi-build",
  "napi-sys",
- "once_cell",
+ "nohash-hasher",
+ "rustc-hash",
 ]
 
 [[package]]
@@ -173,12 +208,12 @@ checksum = "d376940fd5b723c6893cd1ee3f33abbfd86acb1cd1ec079f3ab04a2a3bc4d3b1"
 
 [[package]]
 name = "napi-derive"
-version = "2.16.13"
+version = "3.5.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7cbe2585d8ac223f7d34f13701434b9d5f4eb9c332cccce8dee57ea18ab8ab0c"
+checksum = "89b3f766e04667e6da0e181e2da4f85475d5a6513b7cf6a80bea184e224a5b42"
 dependencies = [
- "cfg-if",
  "convert_case",
+ "ctor 1.0.7",
  "napi-derive-backend",
  "proc-macro2",
  "quote",
@@ -187,33 +222,37 @@ dependencies = [
 
 [[package]]
 name = "napi-derive-backend"
-version = "1.0.75"
+version = "5.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1639aaa9eeb76e91c6ae66da8ce3e89e921cd3885e99ec85f4abacae72fc91bf"
+checksum = "0d5af30503edf933ce7377cf6d4c877a62b0f1107ea05585f1b5e430e88d5baf"
 dependencies = [
  "convert_case",
- "once_cell",
  "proc-macro2",
  "quote",
- "regex",
  "semver",
  "syn",
 ]
 
 [[package]]
 name = "napi-sys"
-version = "2.4.0"
+version = "3.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "427802e8ec3a734331fec1035594a210ce1ff4dc5bc1950530920ab717964ea3"
+checksum = "1f5bcdf71abd3a50d00b49c1c2c75251cb3c913777d6139cd37dabc093a5e400"
 dependencies = [
  "libloading",
 ]
 
 [[package]]
-name = "once_cell"
-version = "1.21.4"
+name = "nohash-hasher"
+version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9f7c3e4beb33f85d45ae3e3a1792185706c8e16d043238c593331cc7cd313b50"
+checksum = "2bf50223579dc7cdcfb3bfcacf7069ff68243f8c363f62ffa99cf000a6b9c451"
+
+[[package]]
+name = "pin-project-lite"
+version = "0.2.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a89322df9ebe1c1578d689c92318e070967d1042b512afbe49518723f4e6d5cd"
 
 [[package]]
 name = "proc-macro2"
@@ -334,13 +373,12 @@ dependencies = [
 name = "react_compiler_reactive_scopes"
 version = "0.1.0"
 dependencies = [
- "hmac",
+ "hmac-sha256",
  "indexmap",
  "react_compiler_ast",
  "react_compiler_diagnostics",
  "react_compiler_hir",
  "serde_json",
- "sha2",
 ]
 
 [[package]]
@@ -350,7 +388,6 @@ dependencies = [
  "indexmap",
  "react_compiler_diagnostics",
  "react_compiler_hir",
- "react_compiler_lowering",
 ]
 
 [[package]]
@@ -379,33 +416,10 @@ dependencies = [
 ]
 
 [[package]]
-name = "regex"
-version = "1.12.3"
+name = "rustc-hash"
+version = "2.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e10754a14b9137dd7b1e3e5b0493cc9171fdd105e0ab477f51b72e7f3ac0e276"
-dependencies = [
- "aho-corasick",
- "memchr",
- "regex-automata",
- "regex-syntax",
-]
-
-[[package]]
-name = "regex-automata"
-version = "0.4.14"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6e1dd4122fc1595e8162618945476892eefca7b88c52820e74af6262213cae8f"
-dependencies = [
- "aho-corasick",
- "memchr",
- "regex-syntax",
-]
-
-[[package]]
-name = "regex-syntax"
-version = "0.8.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc897dd8d9e8bd1ed8cdad82b5966c3e0ecae09fb1907d58efaa013543185d0a"
+checksum = "94300abf3f1ae2e2b8ffb7b58043de3d399c73fa6f4b73826402a5c457614dbe"
 
 [[package]]
 name = "same-file"
@@ -475,27 +489,19 @@ dependencies = [
 ]
 
 [[package]]
-name = "sha2"
-version = "0.10.9"
+name = "similar"
+version = "3.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a7507d819769d01a365ab707794a4084392c824f54a7a6a7862f8c3d0892b283"
+checksum = "e6505efef05804732ed8a3f2d4f279429eb485bd69d5b0cc6b19cc02005cda16"
 dependencies = [
- "cfg-if",
- "cpufeatures",
- "digest",
+ "bstr",
 ]
 
 [[package]]
-name = "similar"
-version = "2.7.0"
+name = "slab"
+version = "0.4.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bbbb5d9659141646ae647b42fe094daf6c6192d1620870b449d9557f748b2daa"
-
-[[package]]
-name = "subtle"
-version = "2.6.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
+checksum = "0c790de23124f9ab44544d7ac05d60440adc586479ce501c1d6d7da3cd8c9cf5"
 
 [[package]]
 name = "syn"
@@ -508,12 +514,6 @@ dependencies = [
  "unicode-ident",
 ]
 
-[[package]]
-name = "typenum"
-version = "1.19.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "562d481066bde0658276a35467c4af00bdc6ee726305698a55b86e61d7ad82bb"
-
 [[package]]
 name = "unicode-ident"
 version = "1.0.24"
@@ -526,12 +526,6 @@ version = "1.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f6ccf251212114b54433ec949fd6a7841275f9ada20dddd2f29e9ceea4501493"
 
-[[package]]
-name = "version_check"
-version = "0.9.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
-
 [[package]]
 name = "walkdir"
 version = "2.5.0"
diff --git a/compiler/crates/react_compiler_ast/Cargo.toml b/compiler/crates/react_compiler_ast/Cargo.toml
index a5b504b0de80..49208522fb5e 100644
--- a/compiler/crates/react_compiler_ast/Cargo.toml
+++ b/compiler/crates/react_compiler_ast/Cargo.toml
@@ -12,4 +12,4 @@ indexmap = { version = "2", features = ["serde"] }
 
 [dev-dependencies]
 walkdir = "2"
-similar = "2"
+similar = "3"
diff --git a/compiler/crates/react_compiler_reactive_scopes/Cargo.toml b/compiler/crates/react_compiler_reactive_scopes/Cargo.toml
index 5ec27f2a5f33..83ce70f37f53 100644
--- a/compiler/crates/react_compiler_reactive_scopes/Cargo.toml
+++ b/compiler/crates/react_compiler_reactive_scopes/Cargo.toml
@@ -9,5 +9,4 @@ react_compiler_diagnostics = { path = "../react_compiler_diagnostics" }
 react_compiler_hir = { path = "../react_compiler_hir" }
 indexmap = "2"
 serde_json = "1"
-sha2 = "0.10"
-hmac = "0.12"
+hmac-sha256 = "1"
diff --git a/compiler/crates/react_compiler_reactive_scopes/src/codegen_reactive_function.rs b/compiler/crates/react_compiler_reactive_scopes/src/codegen_reactive_function.rs
index 55264109fe4d..98aa3935868e 100644
--- a/compiler/crates/react_compiler_reactive_scopes/src/codegen_reactive_function.rs
+++ b/compiler/crates/react_compiler_reactive_scopes/src/codegen_reactive_function.rs
@@ -181,6 +181,17 @@ pub struct OutlinedFunction {
 }
 
 /// Top-level entry point: generates code for a reactive function.
+/// Computes the Fast Refresh source hash used to bust the memo cache when the
+/// source file changes. Matches the TS compiler's
+/// `createHmac('sha256', code).digest('hex')`: an HMAC-SHA256 keyed by the
+/// source code, hashing empty data.
+fn source_file_hash(code: &str) -> String {
+    hmac_sha256::HMAC::mac(b"", code.as_bytes())
+        .iter()
+        .map(|b| format!("{b:02x}"))
+        .collect()
+}
+
 pub fn codegen_function(
     func: &ReactiveFunction,
     env: &mut Environment,
@@ -194,15 +205,7 @@ pub fn codegen_function(
     let fast_refresh_state: Option<(u32, String)> =
         if cx.env.config.enable_reset_cache_on_source_file_changes == Some(true) {
             if let Some(ref code) = cx.env.code {
-                use hmac::Hmac;
-                use hmac::Mac;
-                use sha2::Sha256;
-                type HmacSha256 = Hmac<Sha256>;
-                // Match TS: createHmac('sha256', code).digest('hex')
-                // Node's createHmac uses the code as the HMAC key and hashes empty data.
-                let mac = HmacSha256::new_from_slice(code.as_bytes())
-                    .expect("HMAC can take key of any size");
-                let hash = format!("{:x}", mac.finalize().into_bytes());
+                let hash = source_file_hash(code);
                 let cache_index = cx.alloc_cache_index(); // Reserve slot 0 for the hash check
                 Some((cache_index, hash))
             } else {
@@ -382,7 +385,9 @@ pub fn codegen_function(
                                                     arguments: vec![Expression::StringLiteral(
                                                         StringLiteral {
                                                             base: BaseNode::typed("StringLiteral"),
-                                                            value: MEMO_CACHE_SENTINEL.to_string().into(),
+                                                            value: MEMO_CACHE_SENTINEL
+                                                                .to_string()
+                                                                .into(),
                                                         },
                                                     )],
                                                     type_parameters: None,
@@ -4239,6 +4244,27 @@ mod tests {
 
     use super::{UnsupportedOriginalNode, codegen_unsupported_original_node};
 
+    /// The Fast Refresh source hash must match Node's
+    /// `createHmac('sha256', code).digest('hex')` byte-for-byte, or hot-reload
+    /// cache invalidation would diverge from the TS compiler. Reference values
+    /// were computed with Node's `crypto` module.
+    #[test]
+    fn source_file_hash_matches_node_create_hmac() {
+        use super::source_file_hash;
+        assert_eq!(
+            source_file_hash("hello world"),
+            "0de8bee5d7f9c5d209f8c6fabed0ea84cb3fca1244e8ed38079a61b599a84c47"
+        );
+        assert_eq!(
+            source_file_hash(""),
+            "b613679a0814d9ec772f95d778c35fc5ff1697c493715653c6c712144292c5ad"
+        );
+        assert_eq!(
+            source_file_hash("function App(){}"),
+            "d637acb4985c789d6622c70197db2b62dda282f16f3276aa810b598d6e6cab7b"
+        );
+    }
+
     /// A modeled statement tag parses typed and is emitted directly.
     #[test]
     fn unsupported_original_node_modeled_statement_tag_emits_statement() {
diff --git a/compiler/crates/react_compiler_ssa/Cargo.toml b/compiler/crates/react_compiler_ssa/Cargo.toml
index 3334d93d026d..f0b0f08be0ee 100644
--- a/compiler/crates/react_compiler_ssa/Cargo.toml
+++ b/compiler/crates/react_compiler_ssa/Cargo.toml
@@ -6,5 +6,4 @@ edition = "2024"
 [dependencies]
 react_compiler_diagnostics = { path = "../react_compiler_diagnostics" }
 react_compiler_hir = { path = "../react_compiler_hir" }
-react_compiler_lowering = { path = "../react_compiler_lowering" }
 indexmap = "2"
diff --git a/compiler/packages/babel-plugin-react-compiler-rust/native/Cargo.toml b/compiler/packages/babel-plugin-react-compiler-rust/native/Cargo.toml
index 8af091ca97ba..568787480ade 100644
--- a/compiler/packages/babel-plugin-react-compiler-rust/native/Cargo.toml
+++ b/compiler/packages/babel-plugin-react-compiler-rust/native/Cargo.toml
@@ -7,8 +7,8 @@ edition = "2024"
 crate-type = ["cdylib"]
 
 [dependencies]
-napi = { version = "2", features = ["napi4"] }
-napi-derive = "2"
+napi = { version = "3", features = ["napi4"] }
+napi-derive = "3"
 react_compiler = { path = "../../../crates/react_compiler" }
 react_compiler_ast = { path = "../../../crates/react_compiler_ast" }
 serde = "1"