diff --git a/lib/buffer.js b/lib/buffer.js index b2325098bcbb9d..94bf9cdca30408 100644 --- a/lib/buffer.js +++ b/lib/buffer.js @@ -238,7 +238,7 @@ function fromArrayLike(obj) { } function fromArrayBuffer(obj, byteOffset, length) { - byteOffset >>>= 0; + byteOffset = internalUtil.toInteger(byteOffset); const maxLength = obj.byteLength - byteOffset; @@ -248,7 +248,7 @@ function fromArrayBuffer(obj, byteOffset, length) { if (length === undefined) { length = maxLength; } else { - length >>>= 0; + length = internalUtil.toLength(length); if (length > maxLength) throw new RangeError("'length' is out of bounds"); } diff --git a/lib/internal/util.js b/lib/internal/util.js index 4ada8dd0cc16f0..ae8b1e0b649486 100644 --- a/lib/internal/util.js +++ b/lib/internal/util.js @@ -161,3 +161,21 @@ exports.cachedResult = function cachedResult(fn) { return result; }; }; + +/* + * Implementation of ToInteger as per ECMAScript Specification + * Refer: http://www.ecma-international.org/ecma-262/6.0/#sec-tointeger + */ +const toInteger = exports.toInteger = function toInteger(argument) { + const number = +argument; + return Number.isNaN(number) ? 0 : Math.trunc(number); +}; + +/* + * Implementation of ToLength as per ECMAScript Specification + * Refer: http://www.ecma-international.org/ecma-262/6.0/#sec-tolength + */ +exports.toLength = function toLength(argument) { + const len = toInteger(argument); + return len <= 0 ? 0 : Math.min(len, Number.MAX_SAFE_INTEGER); +}; diff --git a/test/parallel/test-buffer-creation-regression.js b/test/parallel/test-buffer-creation-regression.js new file mode 100644 index 00000000000000..3432d81bf6eddd --- /dev/null +++ b/test/parallel/test-buffer-creation-regression.js @@ -0,0 +1,21 @@ +'use strict'; + +require('../common'); +const assert = require('assert'); + +function test(size, offset, length) { + const arrayBuffer = new ArrayBuffer(size); + + const uint8Array = new Uint8Array(arrayBuffer, offset, length); + for (let i = 0; i < length; i += 1) { + uint8Array[i] = 1; + } + + const buffer = Buffer.from(arrayBuffer, offset, length); + for (let i = 0; i < length; i += 1) { + assert.strictEqual(buffer[i], 1); + } +} + +test(200, 50, 100); +test(8589934592 /* 1 << 40 */, 4294967296 /* 1 << 39 */, 1000); diff --git a/test/parallel/test-internal-util-toInteger.js b/test/parallel/test-internal-util-toInteger.js new file mode 100644 index 00000000000000..57a411964da90f --- /dev/null +++ b/test/parallel/test-internal-util-toInteger.js @@ -0,0 +1,32 @@ +// Flags: --expose-internals +'use strict'; + +require('../common'); +const assert = require('assert'); +const {toInteger} = require('internal/util'); + +const expectZero = [ + '0', '-0', NaN, {}, [], {'a': 'b'}, [1, 2], '0x', '0o', '0b', false, + '', ' ', undefined, null +]; +expectZero.forEach(function(value) { + assert.strictEqual(toInteger(value), 0); +}); + +assert.strictEqual(toInteger(Infinity), Infinity); +assert.strictEqual(toInteger(-Infinity), -Infinity); + +const expectSame = [ + '0x100', '0o100', '0b100', 0x100, -0x100, 0o100, -0o100, 0b100, -0b100, true +]; +expectSame.forEach(function(value) { + assert.strictEqual(toInteger(value), +value, `${value} is not an Integer`); +}); + +const expectIntegers = new Map([ + [[1], 1], [[-1], -1], [['1'], 1], [['-1'], -1], + [3.14, 3], [-3.14, -3], ['3.14', 3], ['-3.14', -3], +]); +expectIntegers.forEach(function(expected, value) { + assert.strictEqual(toInteger(value), expected); +}); diff --git a/test/parallel/test-internal-util-toLength.js b/test/parallel/test-internal-util-toLength.js new file mode 100644 index 00000000000000..ce594c47c1db19 --- /dev/null +++ b/test/parallel/test-internal-util-toLength.js @@ -0,0 +1,35 @@ +// Flags: --expose-internals +'use strict'; + +require('../common'); +const assert = require('assert'); +const {toLength} = require('internal/util'); +const maxValue = Number.MAX_SAFE_INTEGER; + +const expectZero = [ + '0', '-0', NaN, {}, [], {'a': 'b'}, [1, 2], '0x', '0o', '0b', false, + '', ' ', undefined, null, -1, -1.25, -1.1, -1.9, -Infinity +]; +expectZero.forEach(function(value) { + assert.strictEqual(toLength(value), 0); +}); + +assert.strictEqual(toLength(maxValue - 1), maxValue - 1); +assert.strictEqual(maxValue, maxValue); +assert.strictEqual(toLength(Infinity), maxValue); +assert.strictEqual(toLength(maxValue + 1), maxValue); + + +[ + '0x100', '0o100', '0b100', 0x100, -0x100, 0o100, -0o100, 0b100, -0b100, true +].forEach(function(value) { + assert.strictEqual(toLength(value), +value > 0 ? +value : 0); +}); + +const expectIntegers = new Map([ + [[1], 1], [[-1], 0], [['1'], 1], [['-1'], 0], + [3.14, 3], [-3.14, 0], ['3.14', 3], ['-3.14', 0], +]); +expectIntegers.forEach(function(expected, value) { + assert.strictEqual(toLength(value), expected); +});