extracttype

Attempts to extract the type of a JavaScript object. For built-ins
it returns their internal [[Class]] slot, for custom constructed
objects it attempts to extract the name of their constructor. Exports
a function extractType to that end.

BROWSER COMPATIBILITY NOTES

If using with Internet Explorer this function will work better if
you polyfill the missing Function.prototype.name property.

All of the ES 2015+ stuff (arrow fns, const, Symbol, Promise, class,
Object.entries, Array.prototype.from, Array.prototype.includes, etc.
will obviously have to be transpiled/polyfilled). Uses JavaScript
modules (i.e. import/export) and you will need to use a very new
browser or an appropriate loader (e.g. webpack).

NOTE

The isSameType function IS NOT 100% RELIABLE. I highly
recommend simply duck-typing your objects to see if they have the
appropriate method/attribute but there are some corner cases where
it is handy. Use with care. I've annotated the failure conditions
in the function itself best as I can. Note also that it is recursive
and can blow the stack for deeply nested structures if nominal
typing fails. USE WITH CAUTION: I will close without further
comment any github issues that ignore this warning.