buffer: make File cloneable

Fixes: nodejs#47612
KhafraDev · Apr 23, 2023 · 82e6b71 · 82e6b71
1 parent 95e40b5
commit 82e6b71
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Showing 2 changed files with 69 additions and 11 deletions.
diff --git a/lib/internal/file.js b/lib/internal/file.js
@@ -4,6 +4,8 @@ const {
   DateNow,
   NumberIsNaN,
   ObjectDefineProperties,
+  ReflectConstruct,
+  Symbol,
   SymbolToStringTag,
 } = primordials;
 
@@ -21,19 +23,28 @@ const {
 const {
   codes: {
     ERR_MISSING_ARGS,
+    ERR_INVALID_THIS,
   },
 } = require('internal/errors');
 
 const {
   inspect,
 } = require('internal/util/inspect');
 
-class File extends Blob {
-  /** @type {string} */
-  #name;
+const {
+  makeTransferable,
+  kClone,
+  kDeserialize,
+} = require('internal/worker/js_transferable');
 
-  /** @type {number} */
-  #lastModified;
+const kState = Symbol('state');
+
+function isFile(object) {
+  return object?.[kState] !== undefined;
+}
+
+class File extends Blob {
+  [kState] = { __proto__: null };
 
   constructor(fileBits, fileName, options = kEmptyObject) {
     if (arguments.length < 2) {
@@ -55,16 +66,24 @@ class File extends Blob {
       lastModified = DateNow();
     }
 
-    this.#name = toUSVString(fileName);
-    this.#lastModified = lastModified;
+    this[kState].name = toUSVString(fileName);
+    this[kState].lastModified = lastModified;
+
+    makeTransferable(this);
   }
 
   get name() {
-    return this.#name;
+    if (!isFile(this))
+      throw new ERR_INVALID_THIS('File');
+
+    return this[kState].name;
   }
 
   get lastModified() {
-    return this.#lastModified;
+    if (!isFile(this))
+      throw new ERR_INVALID_THIS('File');
+
+    return this[kState].lastModified;
   }
 
   [kInspect](depth, options) {
@@ -80,11 +99,33 @@ class File extends Blob {
     return `File ${inspect({
       size: this.size,
       type: this.type,
-      name: this.#name,
-      lastModified: this.#lastModified,
+      name: this[kState].name,
+      lastModified: this[kState].lastModified,
     }, opts)}`;
   }
+
+  [kClone]() {
+    return {
+      data: { ...super[kClone]().data, ...this[kState] },
+      deserializeInfo: 'internal/file:ClonedFile',
+    };
+  }
+
+  [kDeserialize](data) {
+    super[kDeserialize](data);
+
+    this[kState] = {
+      __proto__: null,
+      name: data.name,
+      lastModified: data.lastModified,
+    };
+  }
+}
+
+function ClonedFile() {
+  return makeTransferable(ReflectConstruct(function() {}, [], File));
 }
+ClonedFile.prototype[kDeserialize] = () => {};
 
 ObjectDefineProperties(File.prototype, {
   name: kEnumerableProperty,
@@ -98,4 +139,5 @@ ObjectDefineProperties(File.prototype, {
 
 module.exports = {
   File,
+  ClonedFile,
 };
diff --git a/test/parallel/test-file.js b/test/parallel/test-file.js
@@ -158,3 +158,19 @@ const { inspect } = require('util');
     );
   });
 }
+
+(async () => {
+  // File should be cloneable via structuredClone.
+  // Refs: https://github.com/nodejs/node/issues/47612
+
+  const body = ['hello, ', 'world'];
+  const lastModified = Date.now() - 10_000;
+  const name = 'hello_world.txt';
+
+  const file = new File(body, name, { lastModified });
+  const clonedFile = structuredClone(file);
+
+  assert.deepStrictEqual(await file.text(), await clonedFile.text());
+  assert.deepStrictEqual(file.lastModified, clonedFile.lastModified);
+  assert.deepStrictEqual(file.name, clonedFile.name);
+})().then(common.mustCall());