Merge commit '6e92d2345e8231a44556ce7d416451f5f3e6c398' as 'engine262'

engine262/src/runtime-semantics/RestBindingInitialization.mts

@@ -0,0 +1,29 @@
+import { Value } from '../value.mts';
+import { surroundingAgent } from '../host-defined/engine.mts';
+import { StringValue } from '../static-semantics/all.mts';
+import { Q } from '../completion.mts';
+import type { ParseNode } from '../parser/ParseNode.mts';
+import {
+  CopyDataProperties,
+  InitializeReferencedBinding,
+  OrdinaryObjectCreate,
+  PutValue,
+  ResolveBinding,
+} from '#self';
+import type { EnvironmentRecord, PropertyKeyValue, UndefinedValue } from '#self';
+
+// BindingRestProperty : `...` BindingIdentifier
+export function* RestBindingInitialization({ BindingIdentifier }: ParseNode.BindingRestProperty, value: Value, environment: EnvironmentRecord | UndefinedValue, excludedNames: readonly PropertyKeyValue[]) {
+  // 1. Let lhs be ? ResolveBinding(StringValue of BindingIdentifier, environment).
+  const lhs = Q(yield* ResolveBinding(StringValue(BindingIdentifier), environment, BindingIdentifier.strict));
+  // 2. Let restObj be OrdinaryObjectCreate(%Object.prototype%).
+  const restObj = OrdinaryObjectCreate(surroundingAgent.intrinsic('%Object.prototype%'));
+  // 3. Perform ? CopyDataProperties(restObj, value, excludedNames).
+  Q(yield* CopyDataProperties(restObj, value, excludedNames));
+  // 4. If environment is undefined, return PutValue(lhs, restObj).
+  if (environment === Value.undefined) {
+    return yield* PutValue(lhs, restObj);
+  }
+  // 5. Return InitializeReferencedBinding(lhs, restObj).
+  return yield* InitializeReferencedBinding(lhs, restObj);
+}