chore: add CMake test target; ignore build directories

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I0db5e008e65f5a5109d8eaa6119b3c246a6a6964

.gitignore

@@ -4,3 +4,4 @@ nix/
 nix-irc
 *.so
 **/*.nixir
+cmake_install.cmake

CMakeLists.txt

@@ -73,3 +73,22 @@ set_target_properties(nix-ir-plugin PROPERTIES
 
 # Install to plugin directory
 install(TARGETS nix-ir-plugin LIBRARY DESTINATION "${CMAKE_INSTALL_PREFIX}/lib/nix/plugins")
+
+# Regression tests
+add_executable(regression_test
+    tests/regression_test.cpp
+    src/irc/serializer.cpp
+)
+
+target_include_directories(regression_test PRIVATE
+    ${CMAKE_SOURCE_DIR}/src
+    ${NIX_STORE_INCLUDE_DIRS}
+    ${NIX_EXPR_INCLUDE_DIRS}
+    ${NIX_UTIL_INCLUDE_DIRS}
+)
+
+target_link_libraries(regression_test PRIVATE
+    ${NIX_STORE_LINK_LIBRARIES}
+    ${NIX_EXPR_LINK_LIBRARIES}
+    ${NIX_UTIL_LINK_LIBRARIES}
+)