Added minimal testing of UDPv4Probe

.gitmodules

@@ -4,3 +4,6 @@
 [submodule "dependencies/libtins"]
 	path = external/libtins
 	url = https://github.com/mfontanini/libtins.git
+[submodule "tests/googletest"]
+	path = googletest
+	url = https://github.com/google/googletest.git

CMakeLists.txt

@@ -94,3 +94,33 @@ if (SETCAP_EXECUTABLE)
         endif()"
     )
 endif()
+
+
+# Testing
+INCLUDE(ExternalProject)
+# Only include googletest if the git submodule has been fetched
+IF(EXISTS "${CMAKE_SOURCE_DIR}/googletest/CMakeLists.txt")
+    # Enable tests and add the test directory
+    MESSAGE(STATUS "Tests have been enabled")
+    SET(GOOGLETEST_ROOT ${CMAKE_SOURCE_DIR}/googletest)
+    SET(GOOGLETEST_INCLUDE ${GOOGLETEST_ROOT}/googletest/include)
+    SET(GOOGLETEST_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/googletest)
+    SET(GOOGLETEST_LIBRARY ${GOOGLETEST_BINARY_DIR}/googletest)
+
+    ExternalProject_Add(
+        googletest
+        DOWNLOAD_COMMAND ""
+        SOURCE_DIR ${GOOGLETEST_ROOT}
+        BINARY_DIR ${GOOGLETEST_BINARY_DIR}
+        CMAKE_CACHE_ARGS "-DBUILD_GTEST:bool=ON" "-DBUILD_GMOCK:bool=OFF"
+                         "-Dgtest_force_shared_crt:bool=ON"
+        INSTALL_COMMAND ""
+    )
+    # Make sure we build googletest before anything else
+    ADD_DEPENDENCIES(dublintraceroute googletest)
+    ENABLE_TESTING()
+    ADD_SUBDIRECTORY(tests)
+ELSE()
+    MESSAGE(STATUS "googletest git submodule is absent. Run `git submodule init && git submodule update` to get it")
+ENDIF()
+

include/dublintraceroute/udpv4probe.h

@@ -10,7 +10,7 @@
  * \sa udpv4probe.cc
  */
 
- #ifndef _UDPV4PROBE_H
+#ifndef _UDPV4PROBE_H
 #define _UDPV4PROBE_H
 
 #include <tins/tins.h>
@@ -30,6 +30,7 @@ class UDPv4Probe {
 	const IPv4Address remote_addr() const { return remote_addr_; }
 	const uint16_t local_port() const { return local_port_; };
 	const uint16_t remote_port() const { return remote_port_; };
+	const uint8_t ttl() const { return ttl_; };
 
 	UDPv4Probe(
 		IPv4Address remote_addr,

tests/CMakeLists.txt

@@ -0,0 +1,3 @@
+INCLUDE_DIRECTORIES(${gtest_INCLUDE_DIRS})
+ADD_SUBDIRECTORY(src)
+

tests/src/CMakeLists.txt

@@ -0,0 +1,36 @@
+# This file is shamelessly copied and modified from libtins.
+# Use dublintraceroute's include directories + test include directories
+INCLUDE_DIRECTORIES(
+    ${PROJECT_SOURCE_DIR}/include/dublintraceroute/
+    ${GOOGLETEST_INCLUDE}
+)
+
+# Find pthread library
+FIND_PACKAGE(Threads REQUIRED)
+
+LINK_DIRECTORIES(
+    ${GOOGLETEST_LIBRARY}
+)
+# Link against GoogleTest, libdublintraceroute and pthread.
+# Pthread is required by GoogleTest
+LINK_LIBRARIES(
+    gtest
+    gtest_main
+    dublintraceroute
+    ${CMAKE_THREAD_LIBS_INIT}
+)
+
+# Add tests target
+ADD_CUSTOM_TARGET(
+    tests DEPENDS
+    UDPv4Test
+    ${OPTIONAL_TEST_TARGETS}
+)
+
+# Test executables
+
+ADD_EXECUTABLE(UDPv4Test EXCLUDE_FROM_ALL udpv4.cxx)
+
+# Tests
+
+ADD_TEST(UDPv4 UDPv4Test)

tests/src/udpv4.cxx

@@ -0,0 +1,26 @@
+#include <dublintraceroute/udpv4probe.h>
+#include <gtest/gtest.h>
+
+
+namespace {
+
+class UDPv4Test: public ::testing::Test {
+};
+
+TEST_F(UDPv4Test, TestUDPv4Constructor) {
+	UDPv4Probe p = UDPv4Probe(IPv4Address("8.8.8.8"), 33434, 12345, 64, IPv4Address("127.0.0.2"));
+	ASSERT_EQ(p.local_port(), 12345);
+	ASSERT_EQ(p.remote_port(), 33434);
+	ASSERT_EQ(p.ttl(), 64);
+	ASSERT_EQ(p.remote_addr().to_string(), std::string("8.8.8.8"));
+	ASSERT_EQ(p.local_addr().to_string(), std::string("127.0.0.2"));
+}
+
+}
+
+
+int main(int argc, char **argv) {
+	::testing::InitGoogleTest(&argc, argv);
+	std::exit(RUN_ALL_TESTS());
+}
+