[pull] main from facebook:main

.eslintrc.js

@@ -608,6 +608,7 @@ module.exports = {
     symbol: 'readonly',
     SyntheticEvent: 'readonly',
     SyntheticMouseEvent: 'readonly',
+    SyntheticPointerEvent: 'readonly',
     Thenable: 'readonly',
     TimeoutID: 'readonly',
     WheelEventHandler: 'readonly',

compiler/packages/babel-plugin-react-compiler/src/HIR/Environment.ts

@@ -608,7 +608,7 @@ export const EnvironmentConfigSchema = z.object({
    *
    * Here the variables `ref` and `myRef` will be typed as Refs.
    */
-  enableTreatRefLikeIdentifiersAsRefs: z.boolean().default(false),
+  enableTreatRefLikeIdentifiersAsRefs: z.boolean().default(true),
 
   /*
    * If specified a value, the compiler lowers any calls to `useContext` to use

compiler/packages/babel-plugin-react-compiler/src/HIR/ObjectShape.ts

@@ -1211,6 +1211,8 @@ addObject(BUILTIN_SHAPES, BuiltInRefValueId, [
   ['*', {kind: 'Object', shapeId: BuiltInRefValueId}],
 ]);
 
+addObject(BUILTIN_SHAPES, ReanimatedSharedValueId, []);
+
 addFunction(
   BUILTIN_SHAPES,
   [],

compiler/packages/babel-plugin-react-compiler/src/Inference/InferReactivePlaces.ts

@@ -21,7 +21,6 @@ import {
   isStableType,
   isStableTypeContainer,
   isUseOperator,
-  isUseRefType,
 } from '../HIR';
 import {PostDominator} from '../HIR/Dominator';
 import {
@@ -70,13 +69,6 @@ class StableSidemap {
               isStable: false,
             });
           }
-        } else if (
-          this.env.config.enableTreatRefLikeIdentifiersAsRefs &&
-          isUseRefType(lvalue.identifier)
-        ) {
-          this.map.set(lvalue.identifier.id, {
-            isStable: true,
-          });
         }
         break;
       }

compiler/packages/babel-plugin-react-compiler/src/TypeInference/InferTypes.ts

@@ -451,6 +451,18 @@ function* generateInstructionTypes(
 
     case 'JsxExpression':
     case 'JsxFragment': {
+      if (env.config.enableTreatRefLikeIdentifiersAsRefs) {
+        if (value.kind === 'JsxExpression') {
+          for (const prop of value.props) {
+            if (prop.kind === 'JsxAttribute' && prop.name === 'ref') {
+              yield equation(prop.place.identifier.type, {
+                kind: 'Object',
+                shapeId: BuiltInUseRefId,
+              });
+            }
+          }
+        }
+      }
       yield equation(left, {kind: 'Object', shapeId: BuiltInJsxId});
       break;
     }
@@ -466,7 +478,36 @@ function* generateInstructionTypes(
       yield equation(left, returnType);
       break;
     }
-    case 'PropertyStore':
+    case 'PropertyStore': {
+      /**
+       * Infer types based on assignments to known object properties
+       * This is important for refs, where assignment to `<maybeRef>.current`
+       * can help us infer that an object itself is a ref
+       */
+      yield equation(
+        /**
+         * Our property type declarations are best-effort and we haven't tested
+         * using them to drive inference of rvalues from lvalues. We want to emit
+         * a Property type in order to infer refs from `.current` accesses, but
+         * stay conservative by not otherwise inferring anything about rvalues.
+         * So we use a dummy type here.
+         *
+         * TODO: consider using the rvalue type here
+         */
+        makeType(),
+        // unify() only handles properties in the second position
+        {
+          kind: 'Property',
+          objectType: value.object.identifier.type,
+          objectName: getName(names, value.object.identifier.id),
+          propertyName: {
+            kind: 'literal',
+            value: value.property,
+          },
+        },
+      );
+      break;
+    }
     case 'DeclareLocal':
     case 'RegExpLiteral':
     case 'MetaProperty':