lib: add FormData global when fetch is enabled

.eslintrc.js

@@ -319,6 +319,7 @@ module.exports = {
     Crypto: 'readable',
     CryptoKey: 'readable',
     fetch: 'readable',
+    FormData: 'readable',
     globalThis: 'readable',
     Response: 'readable',
     SubtleCrypto: 'readable',

doc/api/globals.md

@@ -389,6 +389,17 @@ added: v17.5.0
 
 A browser-compatible implementation of the [`fetch()`][] function.
 
+## Class `FormData`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+> Stability: 1 - Experimental. Enable this API with the [`--experimental-fetch`][]
+> CLI flag.
+
+A browser-compatible implementation of {FormData}.
+
 ## `global`
 
 <!-- YAML

lib/.eslintrc.yaml

@@ -49,6 +49,8 @@ rules:
       message: Use `const { Event } = require('internal/event_target');` instead of the global.
     - name: EventTarget
       message: Use `const { EventTarget } = require('internal/event_target');` instead of the global.
+    - name: FormData
+      message: Use `const { FormData } = require('internal/deps/undici/undici');` instead of the global.
     - name: Headers
       message: Use `const { Headers } = require('internal/deps/undici/undici');` instead of the global.
       # Intl is not available in primordials because it can be

lib/internal/bootstrap/pre_execution.js

@@ -160,6 +160,7 @@ function setupFetch() {
 
   const undici = require('internal/deps/undici/undici');
   defineOperation(globalThis, 'fetch', undici.fetch);
+  exposeInterface(globalThis, 'FormData', undici.FormData);
   exposeInterface(globalThis, 'Headers', undici.Headers);
   exposeInterface(globalThis, 'Request', undici.Request);
   exposeInterface(globalThis, 'Response', undici.Response);

test/common/index.js

@@ -303,6 +303,7 @@ if (global.structuredClone) {
 if (global.fetch) {
   knownGlobals.push(
     global.fetch,
+    global.FormData,
     global.Request,
     global.Response,
     global.Headers,

test/parallel/test-fetch.mjs

@@ -7,6 +7,7 @@ import events from 'events';
 import http from 'http';
 
 assert.strictEqual(typeof globalThis.fetch, 'function');
+assert.strictEqual(typeof globalThis.FormData, 'function');
 assert.strictEqual(typeof globalThis.Headers, 'function');
 assert.strictEqual(typeof globalThis.Request, 'function');
 assert.strictEqual(typeof globalThis.Response, 'function');

test/wpt/test-url.js

@@ -11,7 +11,7 @@ runner.setScriptModifier((obj) => {
     // created via `document.createElement`. So we need to ignore them and just
     // test `URL`.
     obj.code = obj.code.replace(/\["url", "a", "area"\]/, '[ "url" ]');
-  } else if (typeof FormData === 'undefined' && // eslint-disable-line
+  } else if (typeof FormData === 'undefined' &&
       obj.filename.includes('urlsearchparams-constructor.any.js')) {
     // TODO(XadillaX): Remove this `else if` after `FormData` is supported.
 

tools/doc/type-parser.mjs

@@ -271,6 +271,7 @@ const customTypesMap = {
   'TextDecoderStream':
     'webstreams.md#class-textdecoderstream',
 
+  'FormData': 'https://developer.mozilla.org/en-US/docs/Web/API/FormData',
   'Headers': 'https://developer.mozilla.org/en-US/docs/Web/API/Headers',
   'Response': 'https://developer.mozilla.org/en-US/docs/Web/API/Response',
   'Request': 'https://developer.mozilla.org/en-US/docs/Web/API/Request',