[compiler][optim] more shapes for mixedreadonly

- Add `at`, `indexOf`, and `includes`
- Optimize MixedReadOnly which is currently only used by hook return values. Hook return values are typed as Frozen, this change propagates that to return values of aliasing function calls (such as `at`). One potential issue is that  developers may pass `enableAssumeHooksFollowRulesOfReact:false` and set `transitiveMixedData`, expecting their transitive mixed data to be mutable. This is a bit of an edge case and already doesn't have clear semantics.

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

@@ -1126,9 +1126,32 @@ export class Environment {
     );
   }
 
+  getFallthroughPropertyType(
+    receiver: Type,
+    _property: Type,
+  ): BuiltInType | PolyType | null {
+    let shapeId = null;
+    if (receiver.kind === 'Object' || receiver.kind === 'Function') {
+      shapeId = receiver.shapeId;
+    }
+
+    if (shapeId !== null) {
+      const shape = this.#shapes.get(shapeId);
+
+      CompilerError.invariant(shape !== undefined, {
+        reason: `[HIR] Forget internal error: cannot resolve shape ${shapeId}`,
+        description: null,
+        loc: null,
+        suggestions: null,
+      });
+      return shape.properties.get('*') ?? null;
+    }
+    return null;
+  }
+
   getPropertyType(
     receiver: Type,
-    property: string,
+    property: string | number,
   ): BuiltInType | PolyType | null {
     let shapeId = null;
     if (receiver.kind === 'Object' || receiver.kind === 'Function') {
@@ -1146,17 +1169,19 @@ export class Environment {
         loc: null,
         suggestions: null,
       });
-      let value =
+      if (typeof property === 'string') {
-        shape.properties.get(property) ?? shape.properties.get('*') ?? null;
+        return (
-      if (value === null && isHookName(property)) {
+          shape.properties.get(property) ??
-        value = this.#getCustomHookType();
+          shape.properties.get('*') ??
+          (isHookName(property) ? this.#getCustomHookType() : null)
+        );
+      } else {
+        return shape.properties.get('*') ?? null;
       }
-      return value;
+    } else if (typeof property === 'string' && isHookName(property)) {
-    } else if (isHookName(property)) {
       return this.#getCustomHookType();
-    } else {
-      return null;
     }
+    return null;
   }
 
   getFunctionSignature(type: FunctionType): FunctionSignature | null {

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

@@ -119,8 +119,8 @@ const TYPED_GLOBALS: Array<[string, BuiltInType]> = [
       ],
       /*
        * https://tc39.es/ecma262/multipage/indexed-collections.html#sec-array.from
-       * Array.from(arrayLike, optionalFn, optionalThis) not added because
+       * Array.from(arrayLike, optionalFn, optionalThis)
-       * the Effect of `arrayLike` is polymorphic i.e.
+       * Note that the Effect of `arrayLike` is polymorphic i.e.
        *  - Effect.read if
        *     - it does not have an @iterator property and is array-like
        *       (i.e. has a length property)
@@ -128,6 +128,20 @@ const TYPED_GLOBALS: Array<[string, BuiltInType]> = [
        *  - Effect.mutate if it is a self-mutative iterator (e.g. a generator
        *    function)
        */
+      [
+        'from',
+        addFunction(DEFAULT_SHAPES, [], {
+          positionalParams: [
+            Effect.ConditionallyMutate,
+            Effect.ConditionallyMutate,
+            Effect.ConditionallyMutate,
+          ],
+          restParam: Effect.Read,
+          returnType: {kind: 'Object', shapeId: BuiltInArrayId},
+          calleeEffect: Effect.Read,
+          returnValueKind: ValueKind.Mutable,
+        }),
+      ],
       [
         'of',
         // Array.of(element0, ..., elementN)

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

@@ -535,6 +535,30 @@ addObject(BUILTIN_SHAPES, BuiltInRefValueId, [
   ['*', {kind: 'Object', shapeId: BuiltInRefValueId}],
 ]);
 
+/**
+ * MixedReadOnly =
+ *   | primitive
+ *   | simple objects (Record<string, MixedReadOnly>)
+ *   | Array<MixedReadOnly>
+ *
+ * APIs such as Relay — but also Flux and other data stores — often return a
+ * union of types with some interesting properties in terms of analysis.
+ *
+ * Given this constraint, if data came from Relay, then we should be able to
+ * infer things like `data.items.map(): Array`. That may seem like a leap at
+ * first but remember, we assume you're not patching builtins. Thus the only way
+ * data.items.map can exist and be a function, given the above set of data types
+ * and builtin JS methods, is if `data.items` was an Array, and `data.items.map`
+ * is therefore calling Array.prototype.map. Then we know that function returns
+ * an Array as well. This relies on the fact that map() is being called, so if
+ * data.items was some other type it would error at runtime - so it's sound.
+ *
+ * Note that this shape is currently only used for hook return values, which
+ * means that it's safe to type aliasing method-call return kinds as `Frozen`.
+ *
+ * Also note that all newly created arrays from method-calls (e.g. `.map`)
+ * have the appropriate mutable `BuiltInArray` shape
+ */
 addObject(BUILTIN_SHAPES, BuiltInMixedReadonlyId, [
   [
     'toString',
@@ -546,6 +570,36 @@ addObject(BUILTIN_SHAPES, BuiltInMixedReadonlyId, [
       returnValueKind: ValueKind.Primitive,
     }),
   ],
+  [
+    'indexOf',
+    addFunction(BUILTIN_SHAPES, [], {
+      positionalParams: [],
+      restParam: Effect.Read,
+      returnType: {kind: 'Primitive'},
+      calleeEffect: Effect.Read,
+      returnValueKind: ValueKind.Primitive,
+    }),
+  ],
+  [
+    'includes',
+    addFunction(BUILTIN_SHAPES, [], {
+      positionalParams: [],
+      restParam: Effect.Read,
+      returnType: {kind: 'Primitive'},
+      calleeEffect: Effect.Read,
+      returnValueKind: ValueKind.Primitive,
+    }),
+  ],
+  [
+    'at',
+    addFunction(BUILTIN_SHAPES, [], {
+      positionalParams: [Effect.Read],
+      restParam: null,
+      returnType: {kind: 'Object', shapeId: BuiltInMixedReadonlyId},
+      calleeEffect: Effect.Capture,
+      returnValueKind: ValueKind.Frozen,
+    }),
+  ],
   [
     'map',
     addFunction(BUILTIN_SHAPES, [], {
@@ -642,9 +696,9 @@ addObject(BUILTIN_SHAPES, BuiltInMixedReadonlyId, [
     addFunction(BUILTIN_SHAPES, [], {
       positionalParams: [],
       restParam: Effect.ConditionallyMutate,
-      returnType: {kind: 'Poly'},
+      returnType: {kind: 'Object', shapeId: BuiltInMixedReadonlyId},
       calleeEffect: Effect.ConditionallyMutate,
-      returnValueKind: ValueKind.Mutable,
+      returnValueKind: ValueKind.Frozen,
       noAlias: true,
       mutableOnlyIfOperandsAreMutable: true,
     }),

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

@@ -60,7 +60,15 @@ export type PropType = {
   kind: 'Property';
   objectType: Type;
   objectName: string;
-  propertyName: PropertyLiteral;
+  propertyName:
+    | {
+        kind: 'literal';
+        value: PropertyLiteral;
+      }
+    | {
+        kind: 'computed';
+        value: Type;
+      };
 };
 
 export type ObjectMethod = {

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

@@ -872,11 +872,33 @@ function inferBlock(
                 reason: new Set([ValueReason.Other]),
                 context: new Set(),
               };
+
+        for (const element of instrValue.elements) {
+          if (element.kind === 'Spread') {
+            state.referenceAndRecordEffects(
+              freezeActions,
+              element.place,
+              isArrayType(element.place.identifier)
+                ? Effect.Capture
+                : Effect.ConditionallyMutate,
+              ValueReason.Other,
+            );
+          } else if (element.kind === 'Identifier') {
+            state.referenceAndRecordEffects(
+              freezeActions,
+              element,
+              Effect.Capture,
+              ValueReason.Other,
+            );
+          } else {
+            let _: 'Hole' = element.kind;
+          }
+        }
+        state.initialize(instrValue, valueKind);
+        state.define(instr.lvalue, instrValue);
+        instr.lvalue.effect = Effect.Store;
         continuation = {
-          kind: 'initialize',
+          kind: 'funeffects',
-          valueKind,
-          effect: {kind: Effect.Capture, reason: ValueReason.Other},
-          lvalueEffect: Effect.Store,
         };
         break;
       }
@@ -1241,21 +1263,12 @@ function inferBlock(
         for (let i = 0; i < instrValue.args.length; i++) {
           const arg = instrValue.args[i];
           const place = arg.kind === 'Identifier' ? arg : arg.place;
-          if (effects !== null) {
+          state.referenceAndRecordEffects(
-            state.referenceAndRecordEffects(
+            freezeActions,
-              freezeActions,
+            place,
-              place,
+            getArgumentEffect(effects != null ? effects[i] : null, arg),
-              effects[i],
+            ValueReason.Other,
-              ValueReason.Other,
+          );
-            );
-          } else {
-            state.referenceAndRecordEffects(
-              freezeActions,
-              place,
-              Effect.ConditionallyMutate,
-              ValueReason.Other,
-            );
-          }
           hasCaptureArgument ||= place.effect === Effect.Capture;
         }
         if (signature !== null) {
@@ -1307,7 +1320,10 @@ function inferBlock(
           signature !== null
             ? {
                 kind: signature.returnValueKind,
-                reason: new Set([ValueReason.Other]),
+                reason: new Set([
+                  signature.returnValueReason ??
+                    ValueReason.KnownReturnSignature,
+                ]),
                 context: new Set(),
               }
             : {
@@ -1356,25 +1372,16 @@ function inferBlock(
         for (let i = 0; i < instrValue.args.length; i++) {
           const arg = instrValue.args[i];
           const place = arg.kind === 'Identifier' ? arg : arg.place;
-          if (effects !== null) {
+          /*
-            /*
+           * If effects are inferred for an argument, we should fail invalid
-             * If effects are inferred for an argument, we should fail invalid
+           * mutating effects
-             * mutating effects
+           */
-             */
+          state.referenceAndRecordEffects(
-            state.referenceAndRecordEffects(
+            freezeActions,
-              freezeActions,
+            place,
-              place,
+            getArgumentEffect(effects != null ? effects[i] : null, arg),
-              effects[i],
+            ValueReason.Other,
-              ValueReason.Other,
+          );
-            );
-          } else {
-            state.referenceAndRecordEffects(
-              freezeActions,
-              place,
-              Effect.ConditionallyMutate,
-              ValueReason.Other,
-            );
-          }
           hasCaptureArgument ||= place.effect === Effect.Capture;
         }
         if (signature !== null) {
@@ -2049,3 +2056,31 @@ function areArgumentsImmutableAndNonMutating(
   }
   return true;
 }
+
+function getArgumentEffect(
+  signatureEffect: Effect | null,
+  arg: Place | SpreadPattern,
+): Effect {
+  if (signatureEffect != null) {
+    if (arg.kind === 'Identifier') {
+      return signatureEffect;
+    } else if (
+      signatureEffect === Effect.Mutate ||
+      signatureEffect === Effect.ConditionallyMutate
+    ) {
+      return signatureEffect;
+    } else {
+      // see call-spread-argument-mutable-iterator test fixture
+      if (signatureEffect === Effect.Freeze) {
+        CompilerError.throwTodo({
+          reason: 'Support spread syntax for hook arguments',
+          loc: arg.place.loc,
+        });
+      }
+      // effects[i] is Effect.Capture | Effect.Read | Effect.Store
+      return Effect.ConditionallyMutate;
+    }
+  } else {
+    return Effect.ConditionallyMutate;
+  }
+}

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

@@ -307,11 +307,26 @@ function* generateInstructionTypes(
         kind: 'Property',
         objectType: value.object.identifier.type,
         objectName: getName(names, value.object.identifier.id),
-        propertyName: value.property,
+        propertyName: {
+          kind: 'literal',
+          value: value.property,
+        },
       });
       break;
     }
 
+    case 'ComputedLoad': {
+      yield equation(left, {
+        kind: 'Property',
+        objectType: value.object.identifier.type,
+        objectName: getName(names, value.object.identifier.id),
+        propertyName: {
+          kind: 'computed',
+          value: value.property.identifier.type,
+        },
+      });
+      break;
+    }
     case 'MethodCall': {
       const returnType = makeType();
       yield equation(value.property.identifier.type, {
@@ -336,7 +351,10 @@ function* generateInstructionTypes(
               kind: 'Property',
               objectType: value.value.identifier.type,
               objectName: getName(names, value.value.identifier.id),
-              propertyName: makePropertyLiteral(propertyName),
+              propertyName: {
+                kind: 'literal',
+                value: makePropertyLiteral(propertyName),
+              },
             });
           } else {
             break;
@@ -353,7 +371,10 @@ function* generateInstructionTypes(
                 kind: 'Property',
                 objectType: value.value.identifier.type,
                 objectName: getName(names, value.value.identifier.id),
-                propertyName: makePropertyLiteral(property.key.name),
+                propertyName: {
+                  kind: 'literal',
+                  value: makePropertyLiteral(property.key.name),
+                },
               });
             }
           }
@@ -410,7 +431,6 @@ function* generateInstructionTypes(
     case 'RegExpLiteral':
     case 'MetaProperty':
     case 'ComputedStore':
-    case 'ComputedLoad':
     case 'Await':
     case 'GetIterator':
     case 'IteratorNext':
@@ -454,12 +474,13 @@ class Unifier {
         return;
       }
       const objectType = this.get(tB.objectType);
-      let propertyType;
+      const propertyType =
-      if (typeof tB.propertyName === 'number') {
+        tB.propertyName.kind === 'literal'
-        propertyType = null;
+          ? this.env.getPropertyType(objectType, tB.propertyName.value)
-      } else {
+          : this.env.getFallthroughPropertyType(
-        propertyType = this.env.getPropertyType(objectType, tB.propertyName);
+              objectType,
-      }
+              tB.propertyName.value,
+            );
       if (propertyType !== null) {
         this.unify(tA, propertyType);
       }
@@ -677,7 +698,11 @@ class Unifier {
 const RefLikeNameRE = /^(?:[a-zA-Z$_][a-zA-Z$_0-9]*)Ref$|^ref$/;
 
 function isRefLikeName(t: PropType): boolean {
-  return RefLikeNameRE.test(t.objectName) && t.propertyName === 'current';
+  return (
+    t.propertyName.kind === 'literal' &&
+    RefLikeNameRE.test(t.objectName) &&
+    t.propertyName.value === 'current'
+  );
 }
 
 function tryUnionTypes(ty1: Type, ty2: Type): Type | null {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-from-arg1-captures-arg0.expect.md

@@ -0,0 +1,91 @@
+
+## Input
+
+```javascript
+import {useIdentity, Stringify} from 'shared-runtime';
+
+/**
+ * TODO: Note that this `Array.from` is inferred to be mutating its first
+ * argument. This is because React Compiler's typing system does not yet support
+ * annotating a function with a set of argument match cases + distinct
+ * definitions (polymorphism).
+ *
+ * In this case, we should be able to infer that the `Array.from` call is
+ * not mutating its 0th argument.
+ * The 0th argument should be typed as having `effect:Mutate` only when
+ * (1) it might be a mutable iterable or
+ * (2) the 1st argument might mutate its callee
+ */
+function Component({value}) {
+  const arr = [{value: 'foo'}, {value: 'bar'}, {value}];
+  useIdentity();
+  const derived = Array.from(arr, (x, idx) => ({...x, id: idx}));
+  return <Stringify>{derived.at(-1)}</Stringify>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{value: 5}],
+  sequentialRenders: [{value: 5}, {value: 6}, {value: 6}],
+};
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime";
+import { useIdentity, Stringify } from "shared-runtime";
+
+/**
+ * TODO: Note that this `Array.from` is inferred to be mutating its first
+ * argument. This is because React Compiler's typing system does not yet support
+ * annotating a function with a set of argument match cases + distinct
+ * definitions (polymorphism).
+ *
+ * In this case, we should be able to infer that the `Array.from` call is
+ * not mutating its 0th argument.
+ * The 0th argument should be typed as having `effect:Mutate` only when
+ * (1) it might be a mutable iterable or
+ * (2) the 1st argument might mutate its callee
+ */
+function Component(t0) {
+  const $ = _c(4);
+  const { value } = t0;
+  const arr = [{ value: "foo" }, { value: "bar" }, { value }];
+  useIdentity();
+  const derived = Array.from(arr, _temp);
+  let t1;
+  if ($[0] !== derived) {
+    t1 = derived.at(-1);
+    $[0] = derived;
+    $[1] = t1;
+  } else {
+    t1 = $[1];
+  }
+  let t2;
+  if ($[2] !== t1) {
+    t2 = <Stringify>{t1}</Stringify>;
+    $[2] = t1;
+    $[3] = t2;
+  } else {
+    t2 = $[3];
+  }
+  return t2;
+}
+function _temp(x, idx) {
+  return { ...x, id: idx };
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{ value: 5 }],
+  sequentialRenders: [{ value: 5 }, { value: 6 }, { value: 6 }],
+};
+
+```
+      
+### Eval output
+(kind: ok) <div>{"children":{"value":5,"id":2}}</div>
+<div>{"children":{"value":6,"id":2}}</div>
+<div>{"children":{"value":6,"id":2}}</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-from-arg1-captures-arg0.js

@@ -0,0 +1,26 @@
+import {useIdentity, Stringify} from 'shared-runtime';
+
+/**
+ * TODO: Note that this `Array.from` is inferred to be mutating its first
+ * argument. This is because React Compiler's typing system does not yet support
+ * annotating a function with a set of argument match cases + distinct
+ * definitions (polymorphism).
+ *
+ * In this case, we should be able to infer that the `Array.from` call is
+ * not mutating its 0th argument.
+ * The 0th argument should be typed as having `effect:Mutate` only when
+ * (1) it might be a mutable iterable or
+ * (2) the 1st argument might mutate its callee
+ */
+function Component({value}) {
+  const arr = [{value: 'foo'}, {value: 'bar'}, {value}];
+  useIdentity();
+  const derived = Array.from(arr, (x, idx) => ({...x, id: idx}));
+  return <Stringify>{derived.at(-1)}</Stringify>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{value: 5}],
+  sequentialRenders: [{value: 5}, {value: 6}, {value: 6}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-from-captures-arg0.expect.md

@@ -0,0 +1,88 @@
+
+## Input
+
+```javascript
+import {useIdentity, Stringify} from 'shared-runtime';
+
+/**
+ * TODO: Note that this `Array.from` is inferred to be mutating its first
+ * argument. This is because React Compiler's typing system does not yet support
+ * annotating a function with a set of argument match cases + distinct
+ * definitions (polymorphism)
+ *
+ * In this case, we should be able to infer that the `Array.from` call is
+ * not mutating its 0th argument.
+ * The 0th argument should be typed as having `effect:Mutate` only when
+ * (1) it might be a mutable iterable or
+ * (2) the 1st argument might mutate its callee
+ */
+function Component({value}) {
+  const arr = [{value: 'foo'}, {value: 'bar'}, {value}];
+  useIdentity();
+  const derived = Array.from(arr);
+  return <Stringify>{derived.at(-1)}</Stringify>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{value: 5}],
+  sequentialRenders: [{value: 5}, {value: 6}, {value: 6}],
+};
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime";
+import { useIdentity, Stringify } from "shared-runtime";
+
+/**
+ * TODO: Note that this `Array.from` is inferred to be mutating its first
+ * argument. This is because React Compiler's typing system does not yet support
+ * annotating a function with a set of argument match cases + distinct
+ * definitions (polymorphism)
+ *
+ * In this case, we should be able to infer that the `Array.from` call is
+ * not mutating its 0th argument.
+ * The 0th argument should be typed as having `effect:Mutate` only when
+ * (1) it might be a mutable iterable or
+ * (2) the 1st argument might mutate its callee
+ */
+function Component(t0) {
+  const $ = _c(4);
+  const { value } = t0;
+  const arr = [{ value: "foo" }, { value: "bar" }, { value }];
+  useIdentity();
+  const derived = Array.from(arr);
+  let t1;
+  if ($[0] !== derived) {
+    t1 = derived.at(-1);
+    $[0] = derived;
+    $[1] = t1;
+  } else {
+    t1 = $[1];
+  }
+  let t2;
+  if ($[2] !== t1) {
+    t2 = <Stringify>{t1}</Stringify>;
+    $[2] = t1;
+    $[3] = t2;
+  } else {
+    t2 = $[3];
+  }
+  return t2;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{ value: 5 }],
+  sequentialRenders: [{ value: 5 }, { value: 6 }, { value: 6 }],
+};
+
+```
+      
+### Eval output
+(kind: ok) <div>{"children":{"value":5}}</div>
+<div>{"children":{"value":6}}</div>
+<div>{"children":{"value":6}}</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-from-captures-arg0.js

@@ -0,0 +1,26 @@
+import {useIdentity, Stringify} from 'shared-runtime';
+
+/**
+ * TODO: Note that this `Array.from` is inferred to be mutating its first
+ * argument. This is because React Compiler's typing system does not yet support
+ * annotating a function with a set of argument match cases + distinct
+ * definitions (polymorphism)
+ *
+ * In this case, we should be able to infer that the `Array.from` call is
+ * not mutating its 0th argument.
+ * The 0th argument should be typed as having `effect:Mutate` only when
+ * (1) it might be a mutable iterable or
+ * (2) the 1st argument might mutate its callee
+ */
+function Component({value}) {
+  const arr = [{value: 'foo'}, {value: 'bar'}, {value}];
+  useIdentity();
+  const derived = Array.from(arr);
+  return <Stringify>{derived.at(-1)}</Stringify>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{value: 5}],
+  sequentialRenders: [{value: 5}, {value: 6}, {value: 6}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-from-maybemutates-arg0.expect.md

@@ -0,0 +1,64 @@
+
+## Input
+
+```javascript
+import {mutateAndReturn, Stringify, useIdentity} from 'shared-runtime';
+
+function Component({value}) {
+  const arr = [{value: 'foo'}, {value: 'bar'}, {value}];
+  useIdentity();
+  const derived = Array.from(arr, mutateAndReturn);
+  return <Stringify>{derived.at(-1)}</Stringify>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{value: 5}],
+  sequentialRenders: [{value: 5}, {value: 6}, {value: 6}],
+};
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime";
+import { mutateAndReturn, Stringify, useIdentity } from "shared-runtime";
+
+function Component(t0) {
+  const $ = _c(4);
+  const { value } = t0;
+  const arr = [{ value: "foo" }, { value: "bar" }, { value }];
+  useIdentity();
+  const derived = Array.from(arr, mutateAndReturn);
+  let t1;
+  if ($[0] !== derived) {
+    t1 = derived.at(-1);
+    $[0] = derived;
+    $[1] = t1;
+  } else {
+    t1 = $[1];
+  }
+  let t2;
+  if ($[2] !== t1) {
+    t2 = <Stringify>{t1}</Stringify>;
+    $[2] = t1;
+    $[3] = t2;
+  } else {
+    t2 = $[3];
+  }
+  return t2;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{ value: 5 }],
+  sequentialRenders: [{ value: 5 }, { value: 6 }, { value: 6 }],
+};
+
+```
+      
+### Eval output
+(kind: ok) <div>{"children":{"value":5,"wat0":"joe"}}</div>
+<div>{"children":{"value":6,"wat0":"joe"}}</div>
+<div>{"children":{"value":6,"wat0":"joe"}}</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-from-maybemutates-arg0.js

@@ -0,0 +1,14 @@
+import {mutateAndReturn, Stringify, useIdentity} from 'shared-runtime';
+
+function Component({value}) {
+  const arr = [{value: 'foo'}, {value: 'bar'}, {value}];
+  useIdentity();
+  const derived = Array.from(arr, mutateAndReturn);
+  return <Stringify>{derived.at(-1)}</Stringify>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{value: 5}],
+  sequentialRenders: [{value: 5}, {value: 6}, {value: 6}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-spread-later-mutated.expect.md

@@ -0,0 +1,62 @@
+
+## Input
+
+```javascript
+function useBar({arg}) {
+  /**
+   * Note that mutableIterator is mutated by the later object spread. Therefore,
+   * `s.values()` should be memoized within the same block as the object spread.
+   * In terms of compiler internals, they should have the same reactive scope.
+   */
+  const obj = {};
+  const s = new Set([obj, 5, 4]);
+  const mutableIterator = s.values();
+  const arr = [...mutableIterator];
+
+  obj.x = arg;
+  return arr;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useBar,
+  params: [{arg: 3}],
+  sequentialRenders: [{arg: 3}, {arg: 3}, {arg: 4}],
+};
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime";
+function useBar(t0) {
+  const $ = _c(2);
+  const { arg } = t0;
+  let arr;
+  if ($[0] !== arg) {
+    const obj = {};
+    const s = new Set([obj, 5, 4]);
+    const mutableIterator = s.values();
+    arr = [...mutableIterator];
+
+    obj.x = arg;
+    $[0] = arg;
+    $[1] = arr;
+  } else {
+    arr = $[1];
+  }
+  return arr;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useBar,
+  params: [{ arg: 3 }],
+  sequentialRenders: [{ arg: 3 }, { arg: 3 }, { arg: 4 }],
+};
+
+```
+      
+### Eval output
+(kind: ok) [{"x":3},5,4]
+[{"x":3},5,4]
+[{"x":4},5,4]

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-spread-later-mutated.js

@@ -0,0 +1,20 @@
+function useBar({arg}) {
+  /**
+   * Note that mutableIterator is mutated by the later object spread. Therefore,
+   * `s.values()` should be memoized within the same block as the object spread.
+   * In terms of compiler internals, they should have the same reactive scope.
+   */
+  const obj = {};
+  const s = new Set([obj, 5, 4]);
+  const mutableIterator = s.values();
+  const arr = [...mutableIterator];
+
+  obj.x = arg;
+  return arr;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useBar,
+  params: [{arg: 3}],
+  sequentialRenders: [{arg: 3}, {arg: 3}, {arg: 4}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-spread-mutable-iterator.expect.md

@@ -55,26 +55,20 @@ import { c as _c } from "react/compiler-runtime"; /**
 
 function useBar(t0) {
   "use memo";
-  const $ = _c(3);
+  const $ = _c(2);
   const { arg } = t0;
   let t1;
-  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+  if ($[0] !== arg) {
     const s = new Set([1, 5, 4]);
-    t1 = s.values();
+    const mutableIterator = s.values();
-    $[0] = t1;
+
+    t1 = [arg, ...mutableIterator];
+    $[0] = arg;
+    $[1] = t1;
   } else {
-    t1 = $[0];
+    t1 = $[1];
   }
-  const mutableIterator = t1;
+  return t1;
-  let t2;
-  if ($[1] !== arg) {
-    t2 = [arg, ...mutableIterator];
-    $[1] = arg;
-    $[2] = t2;
-  } else {
-    t2 = $[2];
-  }
-  return t2;
 }
 
 export const FIXTURE_ENTRYPOINT = {
@@ -84,4 +78,8 @@ export const FIXTURE_ENTRYPOINT = {
 };
 
 ```
-      
+      
+### Eval output
+(kind: ok) [3,1,5,4]
+[3,1,5,4]
+[4,1,5,4]

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/call-spread-argument-mutable-iterator.expect.md

@@ -0,0 +1,42 @@
+
+## Input
+
+```javascript
+import {useIdentity} from 'shared-runtime';
+
+function useFoo() {
+  const it = new Set([1, 2]).values();
+  useIdentity();
+  return Math.max(...it);
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useFoo,
+  params: [{}],
+  sequentialRenders: [{}, {}],
+};
+
+```
+
+## Code
+
+```javascript
+import { useIdentity } from "shared-runtime";
+
+function useFoo() {
+  const it = new Set([1, 2]).values();
+  useIdentity();
+  return Math.max(...it);
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useFoo,
+  params: [{}],
+  sequentialRenders: [{}, {}],
+};
+
+```
+      
+### Eval output
+(kind: ok) 2
+2

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/call-spread-argument-mutable-iterator.js

@@ -0,0 +1,13 @@
+import {useIdentity} from 'shared-runtime';
+
+function useFoo() {
+  const it = new Set([1, 2]).values();
+  useIdentity();
+  return Math.max(...it);
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useFoo,
+  params: [{}],
+  sequentialRenders: [{}, {}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.todo-hook-call-spreads-mutable-iterator.expect.md

@@ -0,0 +1,33 @@
+
+## Input
+
+```javascript
+import {useIdentity} from 'shared-runtime';
+
+function Component() {
+  const items = makeArray(0, 1, 2, null, 4, false, 6);
+  return useIdentity(...items.values());
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [],
+  sequentialRenders: [{}, {}],
+};
+
+```
+
+
+## Error
+
+```
+  3 | function Component() {
+  4 |   const items = makeArray(0, 1, 2, null, 4, false, 6);
+> 5 |   return useIdentity(...items.values());
+    |                         ^^^^^^^^^^^^^^ Todo: Support spread syntax for hook arguments (5:5)
+  6 | }
+  7 |
+  8 | export const FIXTURE_ENTRYPOINT = {
+```
+          
+      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.todo-hook-call-spreads-mutable-iterator.js

@@ -0,0 +1,12 @@
+import {useIdentity} from 'shared-runtime';
+
+function Component() {
+  const items = makeArray(0, 1, 2, null, 4, false, 6);
+  return useIdentity(...items.values());
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [],
+  sequentialRenders: [{}, {}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.todo-nested-method-calls-lower-property-load-into-temporary.expect.md

@@ -4,9 +4,10 @@
 ```javascript
 import {makeArray} from 'shared-runtime';
 
-function Component(props) {
+const other = [0, 1];
+function Component({}) {
   const items = makeArray(0, 1, 2, null, 4, false, 6);
-  const max = Math.max(...items.filter(Boolean));
+  const max = Math.max(2, items.push(5), ...other);
   return max;
 }
 
@@ -21,13 +22,13 @@ export const FIXTURE_ENTRYPOINT = {
 ## Error
 
 ```
-  3 | function Component(props) {
+  4 | function Component({}) {
-  4 |   const items = makeArray(0, 1, 2, null, 4, false, 6);
+  5 |   const items = makeArray(0, 1, 2, null, 4, false, 6);
-> 5 |   const max = Math.max(...items.filter(Boolean));
+> 6 |   const max = Math.max(2, items.push(5), ...other);
-    |               ^^^^^^^^ Invariant: [Codegen] Internal error: MethodCall::property must be an unpromoted + unmemoized MemberExpression. Got a `Identifier` (5:5)
+    |               ^^^^^^^^ Invariant: [Codegen] Internal error: MethodCall::property must be an unpromoted + unmemoized MemberExpression. Got a `Identifier` (6:6)
-  6 |   return max;
+  7 |   return max;
-  7 | }
+  8 | }
-  8 |
+  9 |
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.todo-nested-method-calls-lower-property-load-into-temporary.js

@@ -1,8 +1,9 @@
 import {makeArray} from 'shared-runtime';
 
-function Component(props) {
+const other = [0, 1];
+function Component({}) {
   const items = makeArray(0, 1, 2, null, 4, false, 6);
-  const max = Math.max(...items.filter(Boolean));
+  const max = Math.max(2, items.push(5), ...other);
   return max;
 }
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/relay-transitive-mixeddata.expect.md

@@ -0,0 +1,61 @@
+
+## Input
+
+```javascript
+import {useFragment} from 'shared-runtime';
+
+/**
+ * React compiler should infer that the returned value is a primitive and avoid
+ * memoizing it.
+ */
+function useRelayData({query, idx}) {
+  'use memo';
+  const data = useFragment('', query);
+  return data.a[idx].toString();
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useRelayData,
+  params: [{query: '', idx: 0}],
+  sequentialRenders: [
+    {query: '', idx: 0},
+    {query: '', idx: 0},
+    {query: '', idx: 1},
+  ],
+};
+
+```
+
+## Code
+
+```javascript
+import { useFragment } from "shared-runtime";
+
+/**
+ * React compiler should infer that the returned value is a primitive and avoid
+ * memoizing it.
+ */
+function useRelayData(t0) {
+  "use memo";
+  const { query, idx } = t0;
+
+  const data = useFragment("", query);
+  return data.a[idx].toString();
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useRelayData,
+  params: [{ query: "", idx: 0 }],
+  sequentialRenders: [
+    { query: "", idx: 0 },
+    { query: "", idx: 0 },
+    { query: "", idx: 1 },
+  ],
+};
+
+```
+      
+### Eval output
+(kind: ok) "1"
+"1"
+"2"

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/relay-transitive-mixeddata.js

@@ -0,0 +1,21 @@
+import {useFragment} from 'shared-runtime';
+
+/**
+ * React compiler should infer that the returned value is a primitive and avoid
+ * memoizing it.
+ */
+function useRelayData({query, idx}) {
+  'use memo';
+  const data = useFragment('', query);
+  return data.a[idx].toString();
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useRelayData,
+  params: [{query: '', idx: 0}],
+  sequentialRenders: [
+    {query: '', idx: 0},
+    {query: '', idx: 0},
+    {query: '', idx: 1},
+  ],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/todo-granular-iterator-semantics.expect.md

@@ -68,21 +68,29 @@ function Validate({ x, input }) {
 }
 function useFoo(input) {
   "use memo";
-  const $ = _c(3);
+  const $ = _c(5);
 
   const x = Array.from([{}]);
   useIdentity();
-  x.push([input]);
   let t0;
-  if ($[0] !== input || $[1] !== x) {
+  if ($[0] !== input) {
-    t0 = <Validate x={x} input={input} />;
+    t0 = [input];
     $[0] = input;
-    $[1] = x;
+    $[1] = t0;
-    $[2] = t0;
   } else {
-    t0 = $[2];
+    t0 = $[1];
   }
-  return t0;
+  x.push(t0);
+  let t1;
+  if ($[2] !== input || $[3] !== x) {
+    t1 = <Validate x={x} input={input} />;
+    $[2] = input;
+    $[3] = x;
+    $[4] = t1;
+  } else {
+    t1 = $[4];
+  }
+  return t1;
 }
 
 export const FIXTURE_ENTRYPOINT = {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/type-inference-array-from.expect.md

@@ -37,6 +37,12 @@ function useFoo({val1, val2}) {
 export const FIXTURE_ENTRYPOINT = {
   fn: useFoo,
   params: [{val1: 1, val2: 2}],
+  params: [
+    {val1: 1, val2: 2},
+    {val1: 1, val2: 2},
+    {val1: 1, val2: 3},
+    {val1: 4, val2: 2},
+  ],
 };
 
 ```
@@ -71,29 +77,51 @@ function Validate({ x, val1, val2 }) {
 }
 function useFoo(t0) {
   "use memo";
-  const $ = _c(4);
+  const $ = _c(8);
   const { val1, val2 } = t0;
 
   const x = Array.from([]);
   useIdentity();
-  x.push([val1]);
-  x.push([val2]);
   let t1;
-  if ($[0] !== val1 || $[1] !== val2 || $[2] !== x) {
+  if ($[0] !== val1) {
-    t1 = <Validate x={x} val1={val1} val2={val2} />;
+    t1 = [val1];
     $[0] = val1;
-    $[1] = val2;
+    $[1] = t1;
-    $[2] = x;
-    $[3] = t1;
   } else {
-    t1 = $[3];
+    t1 = $[1];
   }
-  return t1;
+  x.push(t1);
+  let t2;
+  if ($[2] !== val2) {
+    t2 = [val2];
+    $[2] = val2;
+    $[3] = t2;
+  } else {
+    t2 = $[3];
+  }
+  x.push(t2);
+  let t3;
+  if ($[4] !== val1 || $[5] !== val2 || $[6] !== x) {
+    t3 = <Validate x={x} val1={val1} val2={val2} />;
+    $[4] = val1;
+    $[5] = val2;
+    $[6] = x;
+    $[7] = t3;
+  } else {
+    t3 = $[7];
+  }
+  return t3;
 }
 
 export const FIXTURE_ENTRYPOINT = {
   fn: useFoo,
   params: [{ val1: 1, val2: 2 }],
+  params: [
+    { val1: 1, val2: 2 },
+    { val1: 1, val2: 2 },
+    { val1: 1, val2: 3 },
+    { val1: 4, val2: 2 },
+  ],
 };
 
 ```

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/type-inference-array-from.js

@@ -33,4 +33,10 @@ function useFoo({val1, val2}) {
 export const FIXTURE_ENTRYPOINT = {
   fn: useFoo,
   params: [{val1: 1, val2: 2}],
+  params: [
+    {val1: 1, val2: 2},
+    {val1: 1, val2: 2},
+    {val1: 1, val2: 3},
+    {val1: 4, val2: 2},
+  ],
 };

compiler/packages/snap/src/SproutTodoFilter.ts

@@ -462,7 +462,6 @@ const skipFilter = new Set([
 
   // bugs
   'bug-object-expression-computed-key-modified-during-after-construction-hoisted-sequence-expr',
-  'bug-array-spread-mutable-iterator',
   `bug-capturing-func-maybealias-captured-mutate`,
   'bug-aliased-capture-aliased-mutate',
   'bug-aliased-capture-mutate',