refactor: nit

Author: hi-ogawa

packages/plugin-rsc/src/transforms/hoist.ts

@@ -288,27 +288,23 @@ function synthesizePartialObject(root: string, bindPaths: BindPath[]): string {
     if (node.size === 0) {
       return root + segments.map((segment) => `.${segment}`).join('')
     }
-    const entries = [...node.entries()]
-      .map(
-        ([k, child]) =>
-          `${serializeObjectKey(k)}: ${serialize(child, [...segments, k])}`,
-      )
-      .join(', ')
-    return `{ ${entries} }`
+    const entries: string[] = []
+    for (const [key, child] of node) {
+      // ECMAScript object literals treat `__proto__: value` specially: when the
+      // property name is non-computed and equals "__proto__", evaluation performs
+      // [[SetPrototypeOf]] instead of creating a normal own data property. Emit a
+      // computed key here so synthesized partial objects preserve the original
+      // member-path shape rather than mutating the new object's prototype.
+      // Spec: https://tc39.es/ecma262/#sec-runtime-semantics-propertydefinitionevaluation
+      const safeKey = key === '__proto__' ? `["__proto__"]` : key
+      entries.push(`${safeKey}: ${serialize(child, [...segments, key])}`)
+    }
+    return `{ ${entries.join(', ')} }`
   }
 
   return serialize(trie, [])
 }
 
-function serializeObjectKey(key: string): string {
-  // ECMAScript object literals treat `__proto__: value` specially: when the
-  // property name is non-computed and equals "__proto__", evaluation performs
-  // [[SetPrototypeOf]] instead of creating a normal own data property. Emit a
-  // computed key here so synthesized partial objects preserve the original
-  // member-path shape rather than mutating the new object's prototype.
-  return key === '__proto__' ? `[${JSON.stringify(key)}]` : key
-}
-
 // e.g.
 // [x.y, x.y.z, x.w] -> [x.y, x.w]
 // [x.y.z, x.y.z.w] -> [x.y.z]