fix(Body.body): Normalize Body.body into a node:stream (#924)

* body conversion and test

* also handle blobs

* typeof null is object

* test for blob also

* lowercase boundary are easier

* unreachable code, body should never be a blob or buffer any more.

* stream singleton

* use let

* typo

* convert blob stream into a whatwg stream

* lint fix

* update changelog

Co-authored-by: Antoni Kepinski <xxczaki@pm.me>

docs/CHANGELOG.md

@@ -4,6 +4,11 @@ All notable changes will be recorded here.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## unreleased
+
+- other: Deprecated/Discourage [form-data](https://www.npmjs.com/package/form-data) and body.buffer() (#1212)
+- fix: Normalize `Body.body` into a `node:stream` (#924)
+
 ## v3.0.0
 
 - other: Marking v3 as stable

src/body.js

@@ -36,7 +36,7 @@ export default class Body {
 			// Body is undefined or null
 			body = null;
 		} else if (isURLSearchParameters(body)) {
-		// Body is a URLSearchParams
+			// Body is a URLSearchParams
 			body = Buffer.from(body.toString());
 		} else if (isBlob(body)) {
 			// Body is blob
@@ -52,16 +52,25 @@ export default class Body {
 			// Body is stream
 		} else if (isFormData(body)) {
 			// Body is an instance of formdata-node
-			boundary = `NodeFetchFormDataBoundary${getBoundary()}`;
+			boundary = `nodefetchformdataboundary${getBoundary()}`;
 			body = Stream.Readable.from(formDataIterator(body, boundary));
 		} else {
 			// None of the above
 			// coerce to string then buffer
 			body = Buffer.from(String(body));
 		}
 
+		let stream = body;
+
+		if (Buffer.isBuffer(body)) {
+			stream = Stream.Readable.from(body);
+		} else if (isBlob(body)) {
+			stream = Stream.Readable.from(body.stream());
+		}
+
 		this[INTERNALS] = {
 			body,
+			stream,
 			boundary,
 			disturbed: false,
 			error: null
@@ -79,7 +88,7 @@ export default class Body {
 	}
 
 	get body() {
-		return this[INTERNALS].body;
+		return this[INTERNALS].stream;
 	}
 
 	get bodyUsed() {
@@ -170,23 +179,13 @@ async function consumeBody(data) {
 		throw data[INTERNALS].error;
 	}
 
-	let {body} = data;
+	const {body} = data;
 
 	// Body is null
 	if (body === null) {
 		return Buffer.alloc(0);
 	}
 
-	// Body is blob
-	if (isBlob(body)) {
-		body = Stream.Readable.from(body.stream());
-	}
-
-	// Body is buffer
-	if (Buffer.isBuffer(body)) {
-		return body;
-	}
-
 	/* c8 ignore next 3 */
 	if (!(body instanceof Stream)) {
 		return Buffer.alloc(0);
@@ -238,7 +237,7 @@ async function consumeBody(data) {
 export const clone = (instance, highWaterMark) => {
 	let p1;
 	let p2;
-	let {body} = instance;
+	let {body} = instance[INTERNALS];
 
 	// Don't allow cloning a used body
 	if (instance.bodyUsed) {
@@ -254,7 +253,7 @@ export const clone = (instance, highWaterMark) => {
 		body.pipe(p1);
 		body.pipe(p2);
 		// Set instance body to teed body and return the other teed body
-		instance[INTERNALS].body = p1;
+		instance[INTERNALS].stream = p1;
 		body = p2;
 	}
 
@@ -331,7 +330,7 @@ export const extractContentType = (body, request) => {
  * @returns {number | null}
  */
 export const getTotalBytes = request => {
-	const {body} = request;
+	const {body} = request[INTERNALS];
 
 	// Body is null or undefined
 	if (body === null) {
@@ -373,13 +372,6 @@ export const writeToStream = (dest, {body}) => {
 	if (body === null) {
 		// Body is null
 		dest.end();
-	} else if (isBlob(body)) {
-		// Body is Blob
-		Stream.Readable.from(body.stream()).pipe(dest);
-	} else if (Buffer.isBuffer(body)) {
-		// Body is buffer
-		dest.write(body);
-		dest.end();
 	} else {
 		// Body is stream
 		body.pipe(dest);

src/index.js

@@ -12,7 +12,7 @@ import zlib from 'zlib';
 import Stream, {PassThrough, pipeline as pump} from 'stream';
 import dataUriToBuffer from 'data-uri-to-buffer';
 
-import {writeToStream} from './body.js';
+import {writeToStream, clone} from './body.js';
 import Response from './response.js';
 import Headers, {fromRawHeaders} from './headers.js';
 import Request, {getNodeRequestOptions} from './request.js';
@@ -166,7 +166,7 @@ export default async function fetch(url, options_) {
 							agent: request.agent,
 							compress: request.compress,
 							method: request.method,
-							body: request.body,
+							body: clone(request),
 							signal: request.signal,
 							size: request.size
 						};

src/request.js

@@ -77,7 +77,7 @@ export default class Request extends Body {
 		if (inputBody !== null && !headers.has('Content-Type')) {
 			const contentType = extractContentType(inputBody, this);
 			if (contentType) {
-				headers.append('Content-Type', contentType);
+				headers.set('Content-Type', contentType);
 			}
 		}
 

src/utils/is.js

@@ -35,6 +35,7 @@ export const isURLSearchParameters = object => {
  */
 export const isBlob = object => {
 	return (
+		object &&
 		typeof object === 'object' &&
 		typeof object.arrayBuffer === 'function' &&
 		typeof object.type === 'string' &&

test/response.js

@@ -208,6 +208,38 @@ describe('Response', () => {
 		expect(res.url).to.equal('');
 	});
 
+	it('should cast string to stream using res.body', () => {
+		const res = new Response('hi');
+		expect(res.body).to.be.an.instanceof(stream.Readable);
+	});
+
+	it('should cast typed array to stream using res.body', () => {
+		const res = new Response(Uint8Array.from([97]));
+		expect(res.body).to.be.an.instanceof(stream.Readable);
+	});
+
+	it('should cast blob to stream using res.body', () => {
+		const res = new Response(new Blob(['a']));
+		expect(res.body).to.be.an.instanceof(stream.Readable);
+	});
+
+	it('should not cast null to stream using res.body', () => {
+		const res = new Response(null);
+		expect(res.body).to.be.null;
+	});
+
+	it('should cast typed array to text using res.text()', async () => {
+		const res = new Response(Uint8Array.from([97]));
+		expect(await res.text()).to.equal('a');
+	});
+
+	it('should cast stream to text using res.text() in a roundabout way', async () => {
+		const {body} = new Response('a');
+		expect(body).to.be.an.instanceof(stream.Readable);
+		const res = new Response(body);
+		expect(await res.text()).to.equal('a');
+	});
+
 	it('should support error() static method', () => {
 		const res = Response.error();
 		expect(res).to.be.an.instanceof(Response);