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node_modules/core-js/modules/es.symbol.description.js

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+// `Symbol.prototype.description` getter
+// https://tc39.es/ecma262/#sec-symbol.prototype.description
+'use strict';
+var $ = require('../internals/export');
+var DESCRIPTORS = require('../internals/descriptors');
+var global = require('../internals/global');
+var uncurryThis = require('../internals/function-uncurry-this');
+var hasOwn = require('../internals/has-own-property');
+var isCallable = require('../internals/is-callable');
+var isPrototypeOf = require('../internals/object-is-prototype-of');
+var toString = require('../internals/to-string');
+var defineBuiltInAccessor = require('../internals/define-built-in-accessor');
+var copyConstructorProperties = require('../internals/copy-constructor-properties');
+
+var NativeSymbol = global.Symbol;
+var SymbolPrototype = NativeSymbol && NativeSymbol.prototype;
+
+if (DESCRIPTORS && isCallable(NativeSymbol) && (!('description' in SymbolPrototype) ||
+  // Safari 12 bug
+  NativeSymbol().description !== undefined
+)) {
+  var EmptyStringDescriptionStore = {};
+  // wrap Symbol constructor for correct work with undefined description
+  var SymbolWrapper = function Symbol() {
+    var description = arguments.length < 1 || arguments[0] === undefined ? undefined : toString(arguments[0]);
+    var result = isPrototypeOf(SymbolPrototype, this)
+      ? new NativeSymbol(description)
+      // in Edge 13, String(Symbol(undefined)) === 'Symbol(undefined)'
+      : description === undefined ? NativeSymbol() : NativeSymbol(description);
+    if (description === '') EmptyStringDescriptionStore[result] = true;
+    return result;
+  };
+
+  copyConstructorProperties(SymbolWrapper, NativeSymbol);
+  SymbolWrapper.prototype = SymbolPrototype;
+  SymbolPrototype.constructor = SymbolWrapper;
+
+  var NATIVE_SYMBOL = String(NativeSymbol('test')) == 'Symbol(test)';
+  var thisSymbolValue = uncurryThis(SymbolPrototype.valueOf);
+  var symbolDescriptiveString = uncurryThis(SymbolPrototype.toString);
+  var regexp = /^Symbol\((.*)\)[^)]+$/;
+  var replace = uncurryThis(''.replace);
+  var stringSlice = uncurryThis(''.slice);
+
+  defineBuiltInAccessor(SymbolPrototype, 'description', {
+    configurable: true,
+    get: function description() {
+      var symbol = thisSymbolValue(this);
+      if (hasOwn(EmptyStringDescriptionStore, symbol)) return '';
+      var string = symbolDescriptiveString(symbol);
+      var desc = NATIVE_SYMBOL ? stringSlice(string, 7, -1) : replace(string, regexp, '$1');
+      return desc === '' ? undefined : desc;
+    }
+  });
+
+  $({ global: true, constructor: true, forced: true }, {
+    Symbol: SymbolWrapper
+  });
+}