first

node_modules/core-js/modules/esnext.function.is-callable.js

@@ -0,0 +1,30 @@
+'use strict';
+var $ = require('../internals/export');
+var uncurryThis = require('../internals/function-uncurry-this');
+var $isCallable = require('../internals/is-callable');
+var inspectSource = require('../internals/inspect-source');
+var hasOwn = require('../internals/has-own-property');
+var DESCRIPTORS = require('../internals/descriptors');
+
+// eslint-disable-next-line es/no-object-getownpropertydescriptor -- safe
+var getOwnPropertyDescriptor = Object.getOwnPropertyDescriptor;
+var classRegExp = /^\s*class\b/;
+var exec = uncurryThis(classRegExp.exec);
+
+var isClassConstructor = function (argument) {
+  try {
+    // `Function#toString` throws on some built-it function in some legacy engines
+    // (for example, `DOMQuad` and similar in FF41-)
+    if (!DESCRIPTORS || !exec(classRegExp, inspectSource(argument))) return false;
+  } catch (error) { /* empty */ }
+  var prototype = getOwnPropertyDescriptor(argument, 'prototype');
+  return !!prototype && hasOwn(prototype, 'writable') && !prototype.writable;
+};
+
+// `Function.isCallable` method
+// https://github.com/caitp/TC39-Proposals/blob/trunk/tc39-reflect-isconstructor-iscallable.md
+$({ target: 'Function', stat: true, sham: true, forced: true }, {
+  isCallable: function isCallable(argument) {
+    return $isCallable(argument) && !isClassConstructor(argument);
+  }
+});