build+ci: add code coverage support

This commit also adds GlobalConfigurationFixture to ensure that running
unit tests doesn't interact with system configuration (e.g., doesn't use
or alter user certificates).

Change-Id: I621ce14425a777c94d41b8132cd2858d91235b4d
Refs: #3808
diff --git a/tests/global-configuration-fixture.cpp b/tests/global-configuration-fixture.cpp
new file mode 100644
index 0000000..35ceeed
--- /dev/null
+++ b/tests/global-configuration-fixture.cpp
@@ -0,0 +1,83 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2017,  Regents of the University of California.
+ *
+ * This file is part of ndn-tools (Named Data Networking Essential Tools).
+ * See AUTHORS.md for complete list of ndn-tools authors and contributors.
+ *
+ * ndn-tools is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-tools 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * ndn-tools, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <boost/version.hpp>
+#include <boost/filesystem.hpp>
+
+#include "test-common.hpp"
+
+namespace ndn {
+namespace tools {
+namespace tests {
+
+class GlobalConfigurationFixture : boost::noncopyable
+{
+public:
+  GlobalConfigurationFixture()
+  {
+    if (getenv("HOME") != nullptr) {
+      m_home = getenv("HOME");
+    }
+    if (getenv("NDN_CLIENT_PIB") != nullptr) {
+      m_pib = getenv("NDN_CLIENT_PIB");
+    }
+    if (getenv("NDN_CLIENT_TPM") != nullptr) {
+      m_tpm = getenv("NDN_CLIENT_TPM");
+    }
+
+    boost::filesystem::path dir(TMP_TESTS_PATH);
+    dir /= "test-home";
+    setenv("HOME", dir.generic_string().c_str(), 1);
+
+    if (exists(dir)) {
+      remove_all(dir);
+    }
+
+    setenv("NDN_CLIENT_PIB", ("pib-sqlite3:" + dir.string()).c_str(), 1);
+    setenv("NDN_CLIENT_TPM", ("tpm-file:" + dir.string()).c_str(), 1);
+    create_directories(dir);
+  }
+
+  ~GlobalConfigurationFixture()
+  {
+    if (!m_home.empty()) {
+      setenv("HOME", m_home.c_str(), 1);
+    }
+    if (!m_pib.empty()) {
+      setenv("NDN_CLIENT_PIB", m_pib.c_str(), 1);
+    }
+    if (!m_tpm.empty()) {
+      setenv("NDN_CLIENT_TPM", m_tpm.c_str(), 1);
+    }
+  }
+
+private:
+  std::string m_home;
+  std::string m_pib;
+  std::string m_tpm;
+};
+
+BOOST_GLOBAL_FIXTURE(GlobalConfigurationFixture)
+#if (BOOST_VERSION >= 105900)
+;
+#endif // BOOST_VERSION >= 105900
+
+} // namespace tests
+} // namespace tools
+} // namespace ndn