Fix missing memoization of scope-less variable being reassigned

compiler/forget/packages/babel-plugin-react-forget/src/ReactiveScopes/PropagateScopeDependencies.ts

@@ -419,15 +419,12 @@ class Context {
    * current one as a {@link ReactiveScope.reassignments}
    */
   visitReassignment(place: Place): void {
-    const declaration = this.#declarations.get(place.identifier.id);
     if (
       this.currentScope.value != null &&
-      place.identifier.scope != null &&
-      declaration !== undefined &&
-      declaration.scope.value !== place.identifier.scope &&
       !Array.from(this.currentScope.value.reassignments).some(
-        (ident) => ident.id === place.identifier.id
-      )
+        (identifier) => identifier.id === place.identifier.id
+      ) &&
+      this.#checkValidDependency({ identifier: place.identifier, path: [] })
     ) {
       this.currentScope.value.reassignments.add(place.identifier);
     }

compiler/forget/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/repro-reassign-to-variable-without-mutable-range.expect.md

@@ -0,0 +1,81 @@
+
+## Input
+
+```javascript
+// @debug
+function Component(a, b) {
+  let x = [];
+  let y = [];
+  let z = foo(a);
+  if (FLAG) {
+    x = bar(z);
+    y = baz(b);
+  }
+  return [x, y];
+}
+
+```
+
+## Code
+
+```javascript
+import { unstable_useMemoCache as useMemoCache } from "react"; // @debug
+function Component(a, b) {
+  const $ = useMemoCache(11);
+  let t0;
+  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+    t0 = [];
+    $[0] = t0;
+  } else {
+    t0 = $[0];
+  }
+  let x = t0;
+  let t1;
+  if ($[1] === Symbol.for("react.memo_cache_sentinel")) {
+    t1 = [];
+    $[1] = t1;
+  } else {
+    t1 = $[1];
+  }
+  let y = t1;
+  const c_2 = $[2] !== a;
+  const c_3 = $[3] !== b;
+  if (c_2 || c_3) {
+    const z = foo(a);
+    if (FLAG) {
+      x = bar(z);
+      const c_6 = $[6] !== b;
+      let t2;
+      if (c_6) {
+        t2 = baz(b);
+        $[6] = b;
+        $[7] = t2;
+      } else {
+        t2 = $[7];
+      }
+      y = t2;
+    }
+    $[2] = a;
+    $[3] = b;
+    $[4] = x;
+    $[5] = y;
+  } else {
+    x = $[4];
+    y = $[5];
+  }
+  const c_8 = $[8] !== x;
+  const c_9 = $[9] !== y;
+  let t3;
+  if (c_8 || c_9) {
+    t3 = [x, y];
+    $[8] = x;
+    $[9] = y;
+    $[10] = t3;
+  } else {
+    t3 = $[10];
+  }
+  return t3;
+}
+
+```
+      

compiler/forget/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/repro-reassign-to-variable-without-mutable-range.js

@@ -0,0 +1,11 @@
+// @debug
+function Component(a, b) {
+  let x = [];
+  let y = [];
+  let z = foo(a);
+  if (FLAG) {
+    x = bar(z);
+    y = baz(b);
+  }
+  return [x, y];
+}

compiler/forget/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/ssa-cascading-eliminated-phis.expect.md

@@ -25,7 +25,7 @@ function Component(props) {
 ```javascript
 import { unstable_useMemoCache as useMemoCache } from "react";
 function Component(props) {
-  const $ = useMemoCache(2);
+  const $ = useMemoCache(3);
   let x = 0;
   const c_0 = $[0] !== props;
   let values;
@@ -45,8 +45,10 @@ function Component(props) {
     values.push(x);
     $[0] = props;
     $[1] = values;
+    $[2] = x;
   } else {
     values = $[1];
+    x = $[2];
   }
   return values;
 }