chai assert missing function deepStrictEqual in DefinitelyTyped

missing-chai-assert.js

const assert = require("chai").assert;

console.log (typeof assert);
console.log (Object.keys(assert).indexOf("deepStrictEqual"));
console.log (typeof (assert.deepStrictEqual));

assert.deepStrictEqual(2, 2);
assert.deepStrictEqual({ a: 2, b: { c: 4}}, { a: 2, b: { c: 4}});
assert.throws(() => assert.deepStrictEqual({ a: 2, b: { c: 4}}, { a: 2, b: { c: 6}}));