[NgoQuocViet2001]

.empty is meant to throw when given a function, but since v5 async, generator and async generator functions report tags like AsyncFunction. They miss the case 'function' branch and fall through to the object branch, and with no own enumerable keys the assertion passes:

async function fetchList() { return [1]; }
expect(await fetchList).to.be.empty; // passes; chai 4 threw ".empty was passed a function fetchList"
assert.isEmpty(function* () {}); // passes
expect(async function* () {}).to.not.be.empty; // "expected [AsyncGeneratorFunction] not to be empty"

This adds the three function tags to the existing function case, so every function kind throws .empty was passed a function <name> again. That matches chai 4 and what #1566 did for .a('function'). The message and behaviour for plain functions are unchanged.

Ran:

• npm run lint: 0 errors (same 54 warnings as main)
• npm run test-node after building index.js: 512 passing. The new cases in test/expect.js and test/assert.js fail on main (3 failing).

Checked: .empty / .not.empty on objects, arrays and strings behave as before.