has-tostringtag 

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

Example

var hasSymbolToStringTag = require('has-tostringtag');

hasSymbolToStringTag() === true; // if the environment has native Symbol.toStringTag support. Not polyfillable, not forgeable.

var hasSymbolToStringTagKinda = require('has-tostringtag/shams');
hasSymbolToStringTagKinda() === true; // if the environment has a Symbol.toStringTag sham that mostly follows the spec.

Supported Symbol shams

• get-own-property-symbols npm | github
• core-js npm | github

Tests

Simply clone the repo, npm install, and run npm test