Webpack global

关于 global，各种情况下的实现，来源 "version": "3.11.0"/builtin 目录

var g;

// This works in non-strict mode
g = (function() {
	return this;
})();

try {
	// This works if eval is allowed (see CSP)
	g = g || Function("return this")() || (1,eval)("this");
} catch(e) {
	// This works if the window reference is available
	if(typeof window === "object")
		g = window;
}

// g can still be undefined, but nothing to do about it...
// We return undefined, instead of nothing here, so it's
// easier to handle this case. if(!global) { ...}

module.exports = g;