Allow maxBuffer option to be set to Buffer MAX_LENGTH (#40)

Co-authored-by: Sindre Sorhus <[email protected]>

index.js

@@ -1,4 +1,5 @@
 'use strict';
+const {constants: BufferConstants} = require('buffer');
 const pump = require('pump');
 const bufferStream = require('./buffer-stream');
 
@@ -24,7 +25,8 @@ async function getStream(inputStream, options) {
 	let stream;
 	await new Promise((resolve, reject) => {
 		const rejectPromise = error => {
-			if (error) { // A null check
+			// Don't retrieve an oversized buffer.
+			if (error && stream.getBufferedLength() <= BufferConstants.MAX_LENGTH) {
 				error.bufferedData = stream.getBufferedValue();
 			}
 

test.js

@@ -1,4 +1,5 @@
 import fs from 'fs';
+import {constants as BufferConstants} from 'buffer';
 import {Readable as ReadableStream} from 'stream';
 import test from 'ava';
 import intoStream from 'into-stream';
@@ -70,6 +71,16 @@ test('maxBuffer throws a MaxBufferError', async t => {
 	await t.throwsAsync(setup(['abcd'], {maxBuffer: 3}), getStream.MaxBufferError);
 });
 
+test('maxBuffer throws a MaxBufferError even if the stream is larger than Buffer MAX_LENGTH', async t => {
+	// Create a stream 1 byte larger than the maximum size a buffer is allowed to be
+	function * largeStream() {
+		yield Buffer.allocUnsafe(BufferConstants.MAX_LENGTH);
+		yield Buffer.allocUnsafe(1);
+	}
+
+	await t.throwsAsync(setup(largeStream(), {maxBuffer: BufferConstants.MAX_LENGTH, encoding: 'buffer'}), /maxBuffer exceeded/);
+});
+
 test('Promise rejects when input stream emits an error', async t => {
 	const readable = new ReadableStream();
 	const data = 'invisible pink unicorn';