--- /dev/null
+var $ = require('../internals/export');
+// TODO: in core-js@4, move /modules/ dependencies to public entries for better optimization by tools like `preset-env`
+var Set = require('../modules/es.set');
+var ReflectMetadataModule = require('../internals/reflect-metadata');
+var anObject = require('../internals/an-object');
+var getPrototypeOf = require('../internals/object-get-prototype-of');
+var iterate = require('../internals/iterate');
+
+var ordinaryOwnMetadataKeys = ReflectMetadataModule.keys;
+var toMetadataKey = ReflectMetadataModule.toKey;
+
+var from = function (iter) {
+ var result = [];
+ iterate(iter, result.push, { that: result });
+ return result;
+};
+
+var ordinaryMetadataKeys = function (O, P) {
+ var oKeys = ordinaryOwnMetadataKeys(O, P);
+ var parent = getPrototypeOf(O);
+ if (parent === null) return oKeys;
+ var pKeys = ordinaryMetadataKeys(parent, P);
+ return pKeys.length ? oKeys.length ? from(new Set(oKeys.concat(pKeys))) : pKeys : oKeys;
+};
+
+// `Reflect.getMetadataKeys` method
+// https://github.com/rbuckton/reflect-metadata
+$({ target: 'Reflect', stat: true }, {
+ getMetadataKeys: function getMetadataKeys(target /* , targetKey */) {
+ var targetKey = arguments.length < 2 ? undefined : toMetadataKey(arguments[1]);
+ return ordinaryMetadataKeys(anObject(target), targetKey);
+ }
+});