Fix premature close with chunked Transfer-encoding in Node 12

Author: tekwiz

src/index.js

@@ -95,6 +95,10 @@ export default async function fetch(url, options_) {
 			finalize();
 		});
 
+		fixResponseChunkedTransferBadEnding(request_, err => {
+			response.body.destroy(err);
+		});
+
 		request_.on('response', response_ => {
 			request_.setTimeout(0);
 			const headers = fromRawHeaders(response_.rawHeaders);
@@ -265,3 +269,31 @@ export default async function fetch(url, options_) {
 		writeToStream(request_, request);
 	});
 }
+
+function fixResponseChunkedTransferBadEnding(request, errorCallback) {
+	const LAST_CHUNK = Buffer.from('0\r\n');
+	let socket;
+
+	request.on('socket', s => {
+		socket = s;
+	});
+
+	request.on('response', response => {
+		const {headers} = response;
+		if (headers['transfer-encoding'] === 'chunked' && !headers['content-length']) {
+			let properLastChunkReceived = false;
+
+			socket.on('data', buf => {
+				properLastChunkReceived = Buffer.compare(buf.slice(-3), LAST_CHUNK) === 0;
+			});
+
+			socket.prependListener('close', () => {
+				if (!properLastChunkReceived) {
+					const err = new Error('Premature close');
+					err.code = 'ERR_STREAM_PREMATURE_CLOSE';
+					errorCallback(err);
+				}
+			});
+		}
+	});
+}

test/main.js

@@ -619,15 +619,43 @@ describe('node-fetch', () => {
 			expect(res.status).to.equal(200);
 			expect(res.ok).to.be.true;
 
-			const read = async (body) => {
-				const chunks = [];
-				for await (const chunk of body) {
-					chunks.push(chunk);
-				}
-				return chunks;
-			};
+			return expect(new Promise((resolve, reject) => {
+				res.body.on('error', reject);
+				res.body.on('close', resolve);
+			})).to.eventually.be.rejectedWith(Error, 'Premature close')
+				.and.have.property('code', 'ERR_STREAM_PREMATURE_CLOSE');
+		});
+	});
+
+	// it('should handle network-error in chunked response 2', () => {
+	// 	const url = `${base}error/premature/chunked`;
+	// 	return fetch(url).then(res => {
+	// 		expect(res.status).to.equal(200);
+	// 		expect(res.ok).to.be.true;
+	//
+	// 		const read = async body => {
+	// 			const chunks = [];
+	// 			for await (const chunk of body) {
+	// 				chunks.push(chunk);
+	// 			}
+	//
+	// 			return chunks;
+	// 		};
+	//
+	// 		return expect(read(res.body))
+	// 			.to.eventually.be.rejectedWith(Error, 'Premature close')
+	// 			.and.have.property('code', 'ERR_STREAM_PREMATURE_CLOSE');
+	// 	});
+	// });
+
+	it('should handle network-error in chunked response 2', () => {
+		const url = `${base}error/premature/chunked`;
+		return fetch(url).then(res => {
+			expect(res.status).to.equal(200);
+			expect(res.ok).to.be.true;
 
-			return expect(read(res.body)).to.eventually.be.rejectedWith(Error);
+			return expect(res.text())
+				.to.eventually.be.rejectedWith(Error, 'Premature close');
 		});
 	});
 

test/utils/server.js

@@ -325,19 +325,19 @@ export default class TestServer {
 
 		if (p === '/error/premature/chunked') {
 			res.writeHead(200, {
-				'content-type': 'application/json',
-				'transfer-encoding': 'chunked'
+				'Content-Type': 'application/json',
+				'Transfer-Encoding': 'chunked'
 			});
 
-			res.write(`${JSON.stringify({ data: 'hi' })}\n`);
+			res.write(`${JSON.stringify({data: 'hi'})}\n`);
 
 			setTimeout(() => {
-				res.write(`${JSON.stringify({ data: 'bye' })}\n`);
-			}, 100);
+				res.write(`${JSON.stringify({data: 'bye'})}\n`);
+			}, 200);
 
 			setTimeout(() => {
-				res.destroy()
-			}, 200);
+				res.destroy();
+			}, 400);
 		}
 
 		if (p === '/error/json') {