net: add NetworkMonitorStub

refs #4024

Change-Id: I20da6f3351f51667b045987dc07e88ba814a4456
diff --git a/src/net/network-monitor-stub.hpp b/src/net/network-monitor-stub.hpp
new file mode 100644
index 0000000..97b9d46
--- /dev/null
+++ b/src/net/network-monitor-stub.hpp
@@ -0,0 +1,88 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2017 Regents of the University of California.
+ *
+ * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
+ *
+ * ndn-cxx library is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License and GNU Lesser
+ * General Public License along with ndn-cxx, e.g., in COPYING.md file.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ */
+
+#ifndef NDN_NET_NETWORK_MONITOR_STUB_HPP
+#define NDN_NET_NETWORK_MONITOR_STUB_HPP
+
+#include "network-monitor.hpp"
+
+namespace ndn {
+namespace net {
+
+class NetworkMonitorImplStub;
+
+/** \brief a stub NetworkMonitor for unit testing
+ */
+class NetworkMonitorStub : public NetworkMonitor
+{
+public:
+  /** \brief constructor
+   *  \param capabilities capabilities reported by \p getCapabilities
+   */
+  explicit
+  NetworkMonitorStub(uint32_t capabilities);
+
+  /** \brief create a NetworkInterface instance
+   */
+  static shared_ptr<NetworkInterface>
+  makeNetworkInterface();
+
+  /** \brief emit the \p onInterfaceAdded signal and add \p netif internally
+   *  \param netif new network interface
+   *  \post getNetworkInterface(netif->getName()) == netif
+   *  \post listNetworkInterface() contains netif
+   *  \throw std::invalid_argument a network interface with same name already exists
+   */
+  void
+  addInterface(shared_ptr<NetworkInterface> netif);
+
+  /** \brief emit the \p onInterfaceRemoved signal and remove \p netif internally
+   *  \param ifname network interface name
+   *  \post getNetworkInterface(ifname) == nullptr
+   *  \post listNetworkInterface() does not contains an interface with specified name
+   *  \note If specified interface name does not exist, this operation has no effect.
+   */
+  void
+  removeInterface(const std::string& ifname);
+
+  /** \brief emit the \p onEnumerationCompleted signal
+   *
+   *  A real NetworkMonitor starts with an "enumerating" state, during which the initial
+   *  information about network interfaces is collected from the OS. Upon discovering a network
+   *  interface, it emits the \p onInterfaceAdded signal. When the initial enumerating completes,
+   *  it emits the onEnumerationCompleted signal.
+   *
+   *  To simulate this procedure on a newly constructed MockNetworkMonitor, the caller should
+   *  invoke \p addInterface once for each network interface that already exists, and then invoke
+   *  \p signalEnumerationCompleted .
+   */
+  void
+  emitEnumerationCompleted();
+
+private:
+  NetworkMonitorImplStub&
+  getImpl();
+};
+
+} // namespace net
+} // namespace ndn
+
+#endif // NDN_NET_NETWORK_MONITOR_STUB_HPP