feat: add support for application/x-www-form-urlencoded in request.formData() (#60)

Co-authored-by: Irakli Gozalishvili <contact@gozala.io>

Author: brophdawg11

packages/fetch/src/utils/form-data.js

@@ -1,5 +1,6 @@
 import {randomBytes} from 'crypto';
 import { iterateMultipart } from '@web3-storage/multipart-parser';
+import { FormData } from '../package.js';
 import {isBlob} from './is.js';
 
 const carriage = '\r\n';
@@ -86,8 +87,17 @@ export function getFormDataLength(form, boundary) {
 /**
  * @param {Body & {headers?:Headers}} source
  */
-export const toFormData = async ({ body, headers }) => {
+export const toFormData = async (source) => {
+  let { body, headers } = source;
   const contentType = headers?.get('Content-Type') || ''
+
+  if (contentType.startsWith('application/x-www-form-urlencoded') && body != null) {
+	const form = new FormData();
+	let bodyText = await source.text();
+	new URLSearchParams(bodyText).forEach((v, k) => form.append(k, v));
+	return form;
+  }
+
   const [type, boundary] = contentType.split(/\s*;\s*boundary=/)
   if (type === 'multipart/form-data' && boundary != null && body != null) {
     const form = new FormData()

packages/fetch/test/main.js

@@ -1500,6 +1500,25 @@ describe('node-fetch', () => {
 		});
 	});
 
+	it('should support URLSearchParams as POST body', () => {
+		const params = new URLSearchParams();
+		params.set('key1', 'value1');
+		params.set('key2', 'value2');
+
+		const url = `${base}multipart`;
+		const options = {
+			method: 'POST',
+			body: params
+		};
+
+		return fetch(url, options).then(res => res.json()).then(res => {
+			expect(res.method).to.equal('POST');
+			expect(res.headers['content-type']).to.startWith('application/x-www-form-urlencoded');
+			expect(res.body).to.contain('key1=');
+			expect(res.body).to.contain('key2=');
+		});
+	});
+
 	it('should allow POST request with object body', () => {
 		const url = `${base}inspect`;
 		// Note that fetch simply calls tostring on an object
@@ -1548,6 +1567,21 @@ describe('node-fetch', () => {
 		});
 	});
 
+	it('constructing a Request with URLSearchParams should provide formData()', () => {
+		const parameters = new URLSearchParams();
+		parameters.append('key', 'value');
+		const request = new Request(base, {
+			method: 'POST', 
+			headers: {
+				'Content-Type': 'application/x-www-form-urlencoded',
+			},
+			body: parameters,
+		});
+		return request.formData().then(formData => {
+			expect(formData.get('key')).to.equal('value');
+		});
+	});
+
 	it('should allow POST request with URLSearchParams as body', () => {
 		const parameters = new URLSearchParams();
 		parameters.append('a', '1');