lib,test: do not hardcode Buffer.kMaxLength

V8 will soon support typed arrays as large as the maximum array buffer
length. This patch replaces hardcoded values related to
Buffer.kMaxLength with the actual constant.
It also fixes a test that was passing by accident.

Refs: v8/v8@44b2995
PR-URL: nodejs#49876
Reviewed-By: Richard Lau <[email protected]>
Reviewed-By: Luigi Pinca <[email protected]>
Reviewed-By: Yagiz Nizipli <[email protected]>

Author: targos

lib/internal/blob.js

@@ -24,6 +24,9 @@ const {
   concat,
   getDataObject,
 } = internalBinding('blob');
+const {
+  kMaxLength,
+} = internalBinding('buffer');
 
 const {
   TextDecoder,
@@ -62,7 +65,6 @@ const {
 } = require('internal/errors');
 
 const {
-  isUint32,
   validateDictionary,
 } = require('internal/validators');
 
@@ -160,8 +162,8 @@ class Blob {
       return src;
     });
 
-    if (!isUint32(length))
-      throw new ERR_BUFFER_TOO_LARGE(0xFFFFFFFF);
+    if (length > kMaxLength)
+      throw new ERR_BUFFER_TOO_LARGE(kMaxLength);
 
     this[kHandle] = _createBlob(sources_, length);
     this[kLength] = length;

test/parallel/test-blob-buffer-too-large.js

@@ -3,17 +3,17 @@
 
 const common = require('../common');
 const assert = require('assert');
-const { Blob } = require('buffer');
+const { Blob, kMaxLength } = require('buffer');
 
 if (common.isFreeBSD)
   common.skip('Oversized buffer make the FreeBSD CI runner crash');
 
 try {
-  new Blob([new Uint8Array(0xffffffff), [1]]);
+  new Blob([new Uint8Array(kMaxLength), [1]]);
 } catch (e) {
   if (
     e.message === 'Array buffer allocation failed' ||
-    e.message === 'Invalid typed array length: 4294967295'
+    e.message === `Invalid typed array length: ${kMaxLength}`
   ) {
     common.skip(
       'Insufficient memory on this platform for oversized buffer test.'

test/parallel/test-buffer-alloc.js

@@ -4,13 +4,16 @@ const common = require('../common');
 const assert = require('assert');
 const vm = require('vm');
 
-const SlowBuffer = require('buffer').SlowBuffer;
+const {
+  SlowBuffer,
+  kMaxLength,
+} = require('buffer');
 
 // Verify the maximum Uint8Array size. There is no concrete limit by spec. The
 // internal limits should be updated if this fails.
 assert.throws(
-  () => new Uint8Array(2 ** 32 + 1),
-  { message: 'Invalid typed array length: 4294967297' }
+  () => new Uint8Array(kMaxLength + 1),
+  { message: `Invalid typed array length: ${kMaxLength + 1}` },
 );
 
 const b = Buffer.allocUnsafe(1024);

test/parallel/test-buffer-over-max-length.js

@@ -12,18 +12,8 @@ const bufferMaxSizeMsg = {
   name: 'RangeError',
 };
 
-assert.throws(() => Buffer((-1 >>> 0) + 2), bufferMaxSizeMsg);
-assert.throws(() => SlowBuffer((-1 >>> 0) + 2), bufferMaxSizeMsg);
-assert.throws(() => Buffer.alloc((-1 >>> 0) + 2), bufferMaxSizeMsg);
-assert.throws(() => Buffer.allocUnsafe((-1 >>> 0) + 2), bufferMaxSizeMsg);
-assert.throws(() => Buffer.allocUnsafeSlow((-1 >>> 0) + 2), bufferMaxSizeMsg);
-
 assert.throws(() => Buffer(kMaxLength + 1), bufferMaxSizeMsg);
 assert.throws(() => SlowBuffer(kMaxLength + 1), bufferMaxSizeMsg);
 assert.throws(() => Buffer.alloc(kMaxLength + 1), bufferMaxSizeMsg);
 assert.throws(() => Buffer.allocUnsafe(kMaxLength + 1), bufferMaxSizeMsg);
 assert.throws(() => Buffer.allocUnsafeSlow(kMaxLength + 1), bufferMaxSizeMsg);
-
-// issue GH-4331
-assert.throws(() => Buffer.allocUnsafe(0x100000001), bufferMaxSizeMsg);
-assert.throws(() => Buffer.allocUnsafe(0xFFFFFFFFF), bufferMaxSizeMsg);

test/parallel/test-buffer-tostring-rangeerror.js

@@ -1,17 +1,22 @@
 'use strict';
 require('../common');
 
-// This test ensures that Node.js throws a RangeError when trying to convert a
-// gigantic buffer into a string.
+// This test ensures that Node.js throws an Error when trying to convert a
+// large buffer into a string.
 // Regression test for https://github.com/nodejs/node/issues/649.
 
 const assert = require('assert');
-const SlowBuffer = require('buffer').SlowBuffer;
+const {
+  SlowBuffer,
+  constants: {
+    MAX_STRING_LENGTH,
+  },
+} = require('buffer');
 
-const len = 1422561062959;
+const len = MAX_STRING_LENGTH + 1;
 const message = {
-  code: 'ERR_OUT_OF_RANGE',
-  name: 'RangeError',
+  code: 'ERR_STRING_TOO_LONG',
+  name: 'Error',
 };
 assert.throws(() => Buffer(len).toString('utf8'), message);
 assert.throws(() => SlowBuffer(len).toString('utf8'), message);