typed-array-byte-offset

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

v1.0.4 - 2024-12-18

Commits

• [Tests] split out and enhance "no-proto" tests 64d1a73
• [types] improve types 21f484f
• [Tests] add --disable-proto=delete tests 8f77f2a
• [actions] re-add a finisher; add perms 59c1b7b
• [Deps] update call-bind, gopd, has-proto, reflect.getprototypeof c0c30d5
• [Dev Deps] update @arethetypeswrong/cli, @ljharb/tsconfig, @types/tape 2638bd5
• [Deps] update is-typed-array, reflect.getprototypeof 11540a5
• [Deps] update is-typed-array ad9cb70
• [Dev Deps] update @types/tape 2838854