typed-array-byte-length

typed-array-byte-offset

Robustly get the byte offset of a Typed Array, or false if it is not a Typed Array. Works cross-realm, in every engine, even if the byteOffset property is overridden.

Example

var typedArrayByteOffset = require('typed-array-byte-offset');
var assert = require('assert');

assert.equal(false, typedArrayByteOffset(undefined));
assert.equal(false, typedArrayByteOffset(null));
assert.equal(false, typedArrayByteOffset(false));
assert.equal(false, typedArrayByteOffset(true));
assert.equal(false, typedArrayByteOffset([]));
assert.equal(false, typedArrayByteOffset({}));
assert.equal(false, typedArrayByteOffset(/a/g));
assert.equal(false, typedArrayByteOffset(new RegExp('a', 'g')));
assert.equal(false, typedArrayByteOffset(new Date()));
assert.equal(false, typedArrayByteOffset(42));
assert.equal(false, typedArrayByteOffset(NaN));
assert.equal(false, typedArrayByteOffset(Infinity));
assert.equal(false, typedArrayByteOffset(new Number(42)));
assert.equal(false, typedArrayByteOffset('foo'));
assert.equal(false, typedArrayByteOffset(Object('foo')));
assert.equal(false, typedArrayByteOffset(function () {}));
assert.equal(false, typedArrayByteOffset(function* () {}));
assert.equal(false, typedArrayByteOffset(x => x * x));
assert.equal(false, typedArrayByteOffset([]));

const buffer = new ArrayBuffer(32);

assert.equal(8, typedArrayByteOffset(new Int8Array(buffer, 8)));
assert.equal(8, typedArrayByteOffset(new Uint8Array(buffer, 8)));
assert.equal(8, typedArrayByteOffset(new Uint8ClampedArray(buffer, 8)));
assert.equal(4, typedArrayByteOffset(new Int16Array(buffer, 4)));
assert.equal(4, typedArrayByteOffset(new Uint16Array(buffer, 4)));
assert.equal(8, typedArrayByteOffset(new Int32Array(buffer, 8)));
assert.equal(8, typedArrayByteOffset(new Uint32Array(buffer, 8)));
assert.equal(16, typedArrayByteOffset(new Float32Array(buffer, 16)));
assert.equal(16, typedArrayByteOffset(new Float64Array(buffer, 16)));
assert.equal(16, typedArrayByteOffset(new BigInt64Array(buffer, 16)));
assert.equal(16, typedArrayByteOffset(new BigUint64Array(buffer, 16)));

Tests

Simply clone the repo, npm install, and run npm test

Changelog

v1.0.2 - 2024-12-17

Commits

• [types] improve types fcc9606
• [types] use shared config ca29c46
• [actions] split out node 10-20, and 20+ 9a38c81
• [Dev Deps] update @arethetypeswrong/cli, @ljharb/eslint-config, @ljharb/tsconfig, @types/object-inspect, @types/tape, auto-changelog, object-inspect, tape 78cd1f2
• [Deps] update call-bind, gopd, has-proto, is-typed-array 8c13b84
• [Tests] replace aud with npm audit 0d9aee3
• [Tests] use @arethetypeswrong/cli abf28fa
• [Dev Deps] add missing peer dep dfd248d