inspect-js
typed-array-length 
Robustly get the length of a Typed Array, or false if it is not a Typed Array. Works cross-realm, in every engine, even if the length property is overridden.
Example
var typedArrayLength = require('typed-array-length');
var assert = require('assert');
assert.equal(false, typedArrayLength(undefined));
assert.equal(false, typedArrayLength(null));
assert.equal(false, typedArrayLength(false));
assert.equal(false, typedArrayLength(true));
assert.equal(false, typedArrayLength([]));
assert.equal(false, typedArrayLength({}));
assert.equal(false, typedArrayLength(/a/g));
assert.equal(false, typedArrayLength(new RegExp('a', 'g')));
assert.equal(false, typedArrayLength(new Date()));
assert.equal(false, typedArrayLength(42));
assert.equal(false, typedArrayLength(NaN));
assert.equal(false, typedArrayLength(Infinity));
assert.equal(false, typedArrayLength(new Number(42)));
assert.equal(false, typedArrayLength('foo'));
assert.equal(false, typedArrayLength(Object('foo')));
assert.equal(false, typedArrayLength(function () {}));
assert.equal(false, typedArrayLength(function* () {}));
assert.equal(false, typedArrayLength(x => x * x));
assert.equal(false, typedArrayLength([]));
assert.equal(1, typedArrayLength(new Int8Array(1)));
assert.equal(2, typedArrayLength(new Uint8Array(2)));
assert.equal(3, typedArrayLength(new Uint8ClampedArray(3)));
assert.equal(4, typedArrayLength(new Int16Array(4)));
assert.equal(5, typedArrayLength(new Uint16Array(5)));
assert.equal(6, typedArrayLength(new Int32Array(6)));
assert.equal(7, typedArrayLength(new Uint32Array(7)));
assert.equal(8, typedArrayLength(new Float32Array(8)));
assert.equal(9, typedArrayLength(new Float64Array(9)));
assert.equal(10, typedArrayLength(new BigInt64Array(10)));
assert.equal(11, typedArrayLength(new BigUint64Array(11)));Tests
Simply clone the repo, npm install, and run npm test