README.md

@@ -62,4 +62,4 @@ See [Contributing Guide](https://github.com/capricorn86/happy-dom/blob/master/do
 
 ## License
 
-MIT License © 2020-Present [David Ortner](https://github.com/capricorn86)
+MIT License © 2019-Present [David Ortner](https://github.com/capricorn86)

packages/happy-dom/src/fetch/utilities/FetchBodyUtility.ts

@@ -103,7 +103,7 @@ export default class FetchBodyUtility {
 	 * @returns New stream.
 	 */
 	public static cloneBodyStream(requestOrResponse: {
-		body: ReadableStream;
+		body: ReadableStream | null;
 		bodyUsed: boolean;
 	}): ReadableStream {
 		if (requestOrResponse.bodyUsed) {
@@ -113,6 +113,10 @@ export default class FetchBodyUtility {
 			);
 		}
 
+		if (requestOrResponse.body === null || requestOrResponse.body === undefined) {
+			return null;
+		}
+
 		// If a buffer is set, use it to create a new stream.
 		if (requestOrResponse[PropertySymbol.buffer]) {
 			return this.toReadableStream(requestOrResponse[PropertySymbol.buffer]);

packages/happy-dom/test/fetch/Response.test.ts

@@ -488,6 +488,40 @@ describe('Response', () => {
 			expect(bodyText).toBe('Hello World');
 		});
 
+		it('Can clone Response without body.', async () => {
+			const response = new window.Response(null, {
+				status: 404,
+				statusText: 'Not Found',
+				headers: { 'Content-Type': 'text/plain' }
+			});
+
+			const clone = response.clone();
+
+			expect(clone).not.toBe(response);
+			expect(clone.status).toBe(404);
+			expect(clone.statusText).toBe('Not Found');
+			expect(clone.headers.get('Content-Type')).toBe('text/plain');
+		});
+
+		it('Can clone Response with empty string as body.', async () => {
+			const response = new window.Response('', {
+				status: 404,
+				statusText: 'Not Found',
+				headers: { 'Content-Type': 'text/plain' }
+			});
+
+			const clone = response.clone();
+
+			expect(clone).not.toBe(response);
+			expect(clone.status).toBe(404);
+			expect(clone.statusText).toBe('Not Found');
+			expect(clone.headers.get('Content-Type')).toBe('text/plain');
+
+			const bodyText = await clone.text();
+
+			expect(bodyText).toBe('');
+		});
+
 		it('Can use the body of the cloned Response with a buffer independently.', async () => {
 			const originalResponse = new window.Response('Hello World', {
 				status: 200,