[Refactor] use generator-function

Author: ljharb

index.js

@@ -9,17 +9,7 @@ var getProto = require('get-proto');
 var toStr = callBound('Object.prototype.toString');
 var fnToStr = callBound('Function.prototype.toString');
 
-var getGeneratorFunc = function () { // eslint-disable-line consistent-return
-	if (!hasToStringTag) {
-		return false;
-	}
-	try {
-		return Function('return function*() {}')();
-	} catch (e) {
-	}
-};
-/** @type {undefined | false | null | GeneratorFunctionConstructor} */
-var GeneratorFunction;
+var getGeneratorFunction = require('generator-function');
 
 /** @type {import('.')} */
 module.exports = function isGeneratorFunction(fn) {
@@ -36,12 +26,6 @@ module.exports = function isGeneratorFunction(fn) {
 	if (!getProto) {
 		return false;
 	}
-	if (typeof GeneratorFunction === 'undefined') {
-		var generatorFunc = getGeneratorFunc();
-		GeneratorFunction = generatorFunc
-			// eslint-disable-next-line no-extra-parens
-			? /** @type {GeneratorFunctionConstructor} */ (getProto(generatorFunc))
-			: false;
-	}
-	return getProto(fn) === GeneratorFunction;
+	var GeneratorFunction = getGeneratorFunction();
+	return GeneratorFunction && getProto(fn) === GeneratorFunction;
 };

package.json

@@ -44,6 +44,7 @@
 	},
 	"dependencies": {
 		"call-bound": "^1.0.3",
+		"generator-function": "^2.0.0",
 		"get-proto": "^1.0.0",
 		"has-tostringtag": "^1.0.2",
 		"safe-regex-test": "^1.1.0"