node's assert.deepEqual algorithm

Is this specifier a node.js core module?

string representations of objects in node and the browser

Determine if the JS environment has Symbol support. Supports spec, or shams.

Is this value a JS regex?

Is this an ES6 generator function?

Is this an arguments object? It's a harder question than you think.

Is this value a JS Date object? This module works cross-realm/iframe, and despite ES6 @@toStringTag.

Does this JS environment support the `name` property on functions?

Which kind of Typed Array is this JavaScript value? Works cross-realm, without `instanceof`, and despite Symbol.toStringTag.