wanda: restructure source layoutHEADdevelop

36 files changed, 238 insertions, 215 deletions

diff --git a/source/lib/CMakeLists.txt b/source/lib/CMakeLists.txt
index b9cafe7..f8f2bdb 100644
--- a/source/lib/CMakeLists.txt
+++ b/source/lib/CMakeLists.txt
@@ -1,9 +1,67 @@
-if(WANDA_APPLICATIONS_ONLY)
-  set(WANDA_LIBRARY_TYPE OBJECT)
-endif()
-
-add_subdirectory("control")
-add_subdirectory("meta")
-add_subdirectory("proto")
-add_subdirectory("std_ext")
-add_subdirectory("system")
+file(GLOB_RECURSE HEADERS RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}" CONFIGURE_DEPENDS "include/*.hpp")
+file(GLOB_RECURSE SOURCES RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}" CONFIGURE_DEPENDS "src/*.cpp")
+
+find_package("JPEG" REQUIRED)
+find_package("PNG" REQUIRED)
+find_package("PkgConfig" REQUIRED)
+
+pkg_check_modules("GIO"
+  REQUIRED
+  IMPORTED_TARGET
+  GLOBAL
+  "gio-2.0"
+)
+
+pkg_check_modules("libmagic"
+  REQUIRED
+  IMPORTED_TARGET
+  GLOBAL
+  "libmagic"
+)
+
+add_library("wanda"
+  ${SOURCES}
+)
+
+target_sources("wanda" INTERFACE
+  FILE_SET HEADERS
+  FILES ${HEADERS}
+  BASE_DIRS "include"
+)
+
+target_include_directories("wanda" PUBLIC
+  "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>"
+)
+
+target_include_directories("wanda" SYSTEM PUBLIC
+  "$<INSTALL_INTERFACE:include>"
+)
+
+target_compile_features("wanda" PUBLIC
+  "cxx_std_20"
+)
+
+target_link_libraries("wanda" PUBLIC
+  "Boost::headers"
+  "JPEG::JPEG"
+  "PNG::PNG"
+  "spdlog::spdlog_header_only"
+
+  "PkgConfig::libmagic"
+  "PkgConfig::GIO"
+)
+
+add_executable("wanda-tests"
+  "tests/xdg.cpp"
+)
+
+target_link_libraries("wanda-tests" PRIVATE
+  "wanda"
+  "Catch2::Catch2WithMain"
+)
+
+catch_discover_tests("wanda-tests")
+
+install(TARGETS "wanda"
+  FILE_SET HEADERS
+)
diff --git a/source/lib/control/CMakeLists.txt b/source/lib/control/CMakeLists.txt
deleted file mode 100644
index b4a4b02..0000000
--- a/source/lib/control/CMakeLists.txt
+++ /dev/null
@@ -1,43 +0,0 @@
-cmake_path(GET CMAKE_CURRENT_SOURCE_DIR STEM LIB_NAME)
-
-file(GLOB_RECURSE LIB_HEADERS RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}" CONFIGURE_DEPENDS "**/*.hpp")
-file(GLOB_RECURSE LIB_SOURCES RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}" CONFIGURE_DEPENDS "**/*.cpp")
-
-add_library("wanda-${LIB_NAME}" ${WANDA_LIBRARY_TYPE}
-    ${LIB_SOURCES}
-)
-
-target_sources("wanda-${LIB_NAME}" INTERFACE
-    FILE_SET HEADERS
-    FILES ${LIB_HEADERS}
-    BASE_DIRS "include"
-)
-
-target_include_directories("wanda-${LIB_NAME}" PUBLIC
-    "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>"
-)
-
-target_include_directories("wanda-${LIB_NAME}" SYSTEM PUBLIC
-    "$<INSTALL_INTERFACE:include>"
-)
-
-target_compile_features("wanda-${LIB_NAME}" PUBLIC
-    "cxx_std_20"
-)
-
-target_link_libraries("wanda-${LIB_NAME}" PUBLIC
-    "wanda::meta"
-    "wanda::proto"
-    "wanda::system"
-
-    "Boost::headers"
-    "spdlog::spdlog_header_only"
-)
-
-if(NOT WANDA_APPLICATIONS_ONLY)
-    install(TARGETS "wanda-${LIB_NAME}"
-        FILE_SET HEADERS
-    )
-endif()
-
-add_library("wanda::${LIB_NAME}" ALIAS "wanda-${LIB_NAME}")
diff --git a/source/lib/control/include/wanda/control/commander.hpp b/source/lib/include/wanda/control/commander.hpp
index d7ca73d..d7ca73d 100644
--- a/source/lib/control/include/wanda/control/commander.hpp
+++ b/source/lib/include/wanda/control/commander.hpp
diff --git a/source/lib/control/include/wanda/control/connection.hpp b/source/lib/include/wanda/control/connection.hpp
index 0284fd7..0284fd7 100644
--- a/source/lib/control/include/wanda/control/connection.hpp
+++ b/source/lib/include/wanda/control/connection.hpp
diff --git a/source/lib/control/include/wanda/control/interface.hpp b/source/lib/include/wanda/control/interface.hpp
index e895b68..e895b68 100644
--- a/source/lib/control/include/wanda/control/interface.hpp
+++ b/source/lib/include/wanda/control/interface.hpp
diff --git a/source/lib/meta/include/wanda/meta/deferred_failure.hpp b/source/lib/include/wanda/meta/deferred_failure.hpp
index f74d923..f74d923 100644
--- a/source/lib/meta/include/wanda/meta/deferred_failure.hpp
+++ b/source/lib/include/wanda/meta/deferred_failure.hpp
diff --git a/source/lib/meta/include/wanda/meta/keyed.hpp b/source/lib/include/wanda/meta/keyed.hpp
index a09d1eb..a09d1eb 100644
--- a/source/lib/meta/include/wanda/meta/keyed.hpp
+++ b/source/lib/include/wanda/meta/keyed.hpp
diff --git a/source/lib/meta/include/wanda/meta/type_wrapper.hpp b/source/lib/include/wanda/meta/type_wrapper.hpp
index 1d34c09..1d34c09 100644
--- a/source/lib/meta/include/wanda/meta/type_wrapper.hpp
+++ b/source/lib/include/wanda/meta/type_wrapper.hpp
diff --git a/source/lib/proto/include/wanda/proto/command.hpp b/source/lib/include/wanda/proto/command.hpp
index c8dae65..c8dae65 100644
--- a/source/lib/proto/include/wanda/proto/command.hpp
+++ b/source/lib/include/wanda/proto/command.hpp
diff --git a/source/lib/proto/include/wanda/proto/message.hpp b/source/lib/include/wanda/proto/message.hpp
index 03a30c2..03a30c2 100644
--- a/source/lib/proto/include/wanda/proto/message.hpp
+++ b/source/lib/include/wanda/proto/message.hpp
diff --git a/source/lib/proto/include/wanda/proto/version.hpp b/source/lib/include/wanda/proto/version.hpp
index faa17d7..faa17d7 100644
--- a/source/lib/proto/include/wanda/proto/version.hpp
+++ b/source/lib/include/wanda/proto/version.hpp
diff --git a/source/lib/std_ext/include/wanda/std_ext/expected.hpp b/source/lib/include/wanda/std_ext/expected.hpp
index 83629db..83629db 100644
--- a/source/lib/std_ext/include/wanda/std_ext/expected.hpp
+++ b/source/lib/include/wanda/std_ext/expected.hpp
diff --git a/source/lib/std_ext/include/wanda/std_ext/optional.hpp b/source/lib/include/wanda/std_ext/optional.hpp
index 763e8ac..763e8ac 100644
--- a/source/lib/std_ext/include/wanda/std_ext/optional.hpp
+++ b/source/lib/include/wanda/std_ext/optional.hpp
diff --git a/source/lib/system/include/wanda/system/environment.hpp b/source/lib/include/wanda/system/environment.hpp
index 8cd9ecf..8cd9ecf 100644
--- a/source/lib/system/include/wanda/system/environment.hpp
+++ b/source/lib/include/wanda/system/environment.hpp
diff --git a/source/lib/system/include/wanda/system/filesystem.hpp b/source/lib/include/wanda/system/filesystem.hpp
index 971db90..971db90 100644
--- a/source/lib/system/include/wanda/system/filesystem.hpp
+++ b/source/lib/include/wanda/system/filesystem.hpp
diff --git a/source/lib/system/include/wanda/system/logging.hpp b/source/lib/include/wanda/system/logging.hpp
index 8a9a90e..8a9a90e 100644
--- a/source/lib/system/include/wanda/system/logging.hpp
+++ b/source/lib/include/wanda/system/logging.hpp
diff --git a/source/lib/system/include/wanda/system/magic.hpp b/source/lib/include/wanda/system/magic.hpp
index a8ea1ba..a8ea1ba 100644
--- a/source/lib/system/include/wanda/system/magic.hpp
+++ b/source/lib/include/wanda/system/magic.hpp
diff --git a/source/lib/system/include/wanda/system/setting.hpp b/source/lib/include/wanda/system/setting.hpp
index e0be3f4..e0be3f4 100644
--- a/source/lib/system/include/wanda/system/setting.hpp
+++ b/source/lib/include/wanda/system/setting.hpp
diff --git a/source/lib/system/include/wanda/system/wallpaper.hpp b/source/lib/include/wanda/system/wallpaper.hpp
index 7965fb0..7965fb0 100644
--- a/source/lib/system/include/wanda/system/wallpaper.hpp
+++ b/source/lib/include/wanda/system/wallpaper.hpp
diff --git a/source/lib/system/include/wanda/system/xdg.hpp b/source/lib/include/wanda/system/xdg.hpp
index ae01feb..ae01feb 100644
--- a/source/lib/system/include/wanda/system/xdg.hpp
+++ b/source/lib/include/wanda/system/xdg.hpp
diff --git a/source/lib/meta/CMakeLists.txt b/source/lib/meta/CMakeLists.txt
deleted file mode 100644
index d21d45c..0000000
--- a/source/lib/meta/CMakeLists.txt
+++ /dev/null
@@ -1,31 +0,0 @@
-cmake_path(GET CMAKE_CURRENT_SOURCE_DIR STEM LIB_NAME)
-
-file(GLOB_RECURSE LIB_HEADERS RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}" CONFIGURE_DEPENDS "**/*.hpp")
-
-add_library("wanda-${LIB_NAME}" INTERFACE)
-
-target_sources("wanda-${LIB_NAME}" INTERFACE
-    FILE_SET HEADERS
-    FILES ${LIB_HEADERS}
-    BASE_DIRS "include"
-)
-
-target_include_directories("wanda-${LIB_NAME}" INTERFACE
-    "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>"
-)
-
-target_include_directories("wanda-${LIB_NAME}" SYSTEM INTERFACE
-    "$<INSTALL_INTERFACE:include>"
-)
-
-target_compile_features("wanda-${LIB_NAME}" INTERFACE
-    "cxx_std_20"
-)
-
-if(NOT WANDA_APPLICATIONS_ONLY)
-    install(TARGETS "wanda-${LIB_NAME}"
-        FILE_SET HEADERS
-    )
-endif()
-
-add_library("wanda::${LIB_NAME}" ALIAS "wanda-${LIB_NAME}")
diff --git a/source/lib/proto/CMakeLists.txt b/source/lib/proto/CMakeLists.txt
deleted file mode 100644
index b20663c..0000000
--- a/source/lib/proto/CMakeLists.txt
+++ /dev/null
@@ -1,38 +0,0 @@
-cmake_path(GET CMAKE_CURRENT_SOURCE_DIR STEM LIB_NAME)
-
-file(GLOB_RECURSE LIB_HEADERS RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}" CONFIGURE_DEPENDS "**/*.hpp")
-file(GLOB_RECURSE LIB_SOURCES RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}" CONFIGURE_DEPENDS "**/*.cpp")
-
-add_library("wanda-${LIB_NAME}" ${WANDA_LIBRARY_TYPE}
-    ${LIB_SOURCES}
-)
-
-target_sources("wanda-${LIB_NAME}" INTERFACE
-    FILE_SET HEADERS
-    FILES ${LIB_HEADERS}
-    BASE_DIRS "include"
-)
-
-target_include_directories("wanda-${LIB_NAME}" PUBLIC
-    "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>"
-)
-
-target_include_directories("wanda-${LIB_NAME}" SYSTEM PUBLIC
-    "$<INSTALL_INTERFACE:include>"
-)
-
-target_compile_features("wanda-${LIB_NAME}" PUBLIC
-    "cxx_std_20"
-)
-
-target_link_libraries("wanda-${LIB_NAME}" PUBLIC
-    "spdlog::spdlog_header_only"
-)
-
-if(NOT WANDA_APPLICATIONS_ONLY)
-    install(TARGETS "wanda-${LIB_NAME}"
-        FILE_SET HEADERS
-    )
-endif()
-
-add_library("wanda::${LIB_NAME}" ALIAS "wanda-${LIB_NAME}")
diff --git a/source/lib/control/src/commander.cpp b/source/lib/src/control/commander.cpp
index 4490bb7..4490bb7 100644
--- a/source/lib/control/src/commander.cpp
+++ b/source/lib/src/control/commander.cpp
diff --git a/source/lib/control/src/connection.cpp b/source/lib/src/control/connection.cpp
index 97f41dd..97f41dd 100644
--- a/source/lib/control/src/connection.cpp
+++ b/source/lib/src/control/connection.cpp
diff --git a/source/lib/control/src/interface.cpp b/source/lib/src/control/interface.cpp
index 3ebc55a..3ebc55a 100644
--- a/source/lib/control/src/interface.cpp
+++ b/source/lib/src/control/interface.cpp
diff --git a/source/lib/proto/src/command.cpp b/source/lib/src/proto/command.cpp
index 5a669f5..5a669f5 100644
--- a/source/lib/proto/src/command.cpp
+++ b/source/lib/src/proto/command.cpp
diff --git a/source/lib/proto/src/message.cpp b/source/lib/src/proto/message.cpp
index f44ca06..f44ca06 100644
--- a/source/lib/proto/src/message.cpp
+++ b/source/lib/src/proto/message.cpp
diff --git a/source/lib/system/src/environment.cpp b/source/lib/src/system/environment.cpp
index 8f79531..8f79531 100644
--- a/source/lib/system/src/environment.cpp
+++ b/source/lib/src/system/environment.cpp
diff --git a/source/lib/system/src/filesystem.cpp b/source/lib/src/system/filesystem.cpp
index 04dfff3..04dfff3 100644
--- a/source/lib/system/src/filesystem.cpp
+++ b/source/lib/src/system/filesystem.cpp
diff --git a/source/lib/system/src/logging.cpp b/source/lib/src/system/logging.cpp
index 83dc9f6..83dc9f6 100644
--- a/source/lib/system/src/logging.cpp
+++ b/source/lib/src/system/logging.cpp
diff --git a/source/lib/system/src/setting.cpp b/source/lib/src/system/setting.cpp
index 1553eae..1553eae 100644
--- a/source/lib/system/src/setting.cpp
+++ b/source/lib/src/system/setting.cpp
diff --git a/source/lib/system/src/wallpaper.cpp b/source/lib/src/system/wallpaper.cpp
index 11a6402..11a6402 100644
--- a/source/lib/system/src/wallpaper.cpp
+++ b/source/lib/src/system/wallpaper.cpp
diff --git a/source/lib/system/src/xdg.cpp b/source/lib/src/system/xdg.cpp
index 109beb1..109beb1 100644
--- a/source/lib/system/src/xdg.cpp
+++ b/source/lib/src/system/xdg.cpp
diff --git a/source/lib/std_ext/CMakeLists.txt b/source/lib/std_ext/CMakeLists.txt
deleted file mode 100644
index d21d45c..0000000
--- a/source/lib/std_ext/CMakeLists.txt
+++ /dev/null
@@ -1,31 +0,0 @@
-cmake_path(GET CMAKE_CURRENT_SOURCE_DIR STEM LIB_NAME)
-
-file(GLOB_RECURSE LIB_HEADERS RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}" CONFIGURE_DEPENDS "**/*.hpp")
-
-add_library("wanda-${LIB_NAME}" INTERFACE)
-
-target_sources("wanda-${LIB_NAME}" INTERFACE
-    FILE_SET HEADERS
-    FILES ${LIB_HEADERS}
-    BASE_DIRS "include"
-)
-
-target_include_directories("wanda-${LIB_NAME}" INTERFACE
-    "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>"
-)
-
-target_include_directories("wanda-${LIB_NAME}" SYSTEM INTERFACE
-    "$<INSTALL_INTERFACE:include>"
-)
-
-target_compile_features("wanda-${LIB_NAME}" INTERFACE
-    "cxx_std_20"
-)
-
-if(NOT WANDA_APPLICATIONS_ONLY)
-    install(TARGETS "wanda-${LIB_NAME}"
-        FILE_SET HEADERS
-    )
-endif()
-
-add_library("wanda::${LIB_NAME}" ALIAS "wanda-${LIB_NAME}")
diff --git a/source/lib/system/CMakeLists.txt b/source/lib/system/CMakeLists.txt
deleted file mode 100644
index 7589c56..0000000
--- a/source/lib/system/CMakeLists.txt
+++ /dev/null
@@ -1,63 +0,0 @@
-cmake_path(GET CMAKE_CURRENT_SOURCE_DIR STEM LIB_NAME)
-
-file(GLOB_RECURSE LIB_HEADERS RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}" CONFIGURE_DEPENDS "**/*.hpp")
-file(GLOB_RECURSE LIB_SOURCES RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}" CONFIGURE_DEPENDS "**/*.cpp")
-
-find_package("PkgConfig" REQUIRED)
-
-pkg_check_modules("GIO"
-  REQUIRED
-  IMPORTED_TARGET
-  GLOBAL
-  "gio-2.0"
-)
-
-pkg_check_modules("libmagic"
-  REQUIRED
-  IMPORTED_TARGET
-  GLOBAL
-  "libmagic"
-)
-
-add_library("wanda-${LIB_NAME}" ${WANDA_LIBRARY_TYPE}
-    ${LIB_SOURCES}
-)
-
-target_sources("wanda-${LIB_NAME}" INTERFACE
-    FILE_SET HEADERS
-    FILES ${LIB_HEADERS}
-    BASE_DIRS "include"
-)
-
-target_include_directories("wanda-${LIB_NAME}" PUBLIC
-    "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>"
-)
-
-target_include_directories("wanda-${LIB_NAME}" SYSTEM PUBLIC
-    "$<INSTALL_INTERFACE:include>"
-)
-
-target_compile_features("wanda-${LIB_NAME}" PUBLIC
-    "cxx_std_20"
-)
-
-target_link_libraries("wanda-${LIB_NAME}" PUBLIC
-    "wanda::meta"
-    "wanda::std_ext"
-
-    "Boost::headers"
-    "JPEG::JPEG"
-    "PNG::PNG"
-    "spdlog::spdlog_header_only"
-
-    "PkgConfig::libmagic"
-    "PkgConfig::GIO"
-)
-
-if(NOT WANDA_APPLICATIONS_ONLY)
-    install(TARGETS "wanda-${LIB_NAME}"
-        FILE_SET HEADERS
-    )
-endif()
-
-add_library("wanda::${LIB_NAME}" ALIAS "wanda-${LIB_NAME}")
diff --git a/source/lib/tests/xdg.cpp b/source/lib/tests/xdg.cpp
new file mode 100644
index 0000000..5872dc6
--- /dev/null
+++ b/source/lib/tests/xdg.cpp
@@ -0,0 +1,171 @@
+#include "wanda/system/xdg.hpp"
+
+#include "wanda/system/environment.hpp"
+
+#include <catch2/catch_all.hpp>
+#include <unistd.h>
+
+#include <filesystem>
+#include <string>
+#include <utility>
+
+using namespace std::string_literals;
+
+namespace wanda::system::test
+{
+
+  TEST_CASE("XDG variable names match the specification", "[system][xdg][spec]")
+  {
+    REQUIRE(xdg_variable(xdg_directory::data_home) == "XDG_DATA_HOME");
+    REQUIRE(xdg_variable(xdg_directory::config_home) == "XDG_CONFIG_HOME");
+    REQUIRE(xdg_variable(xdg_directory::cache_home) == "XDG_CACHE_HOME");
+    REQUIRE(xdg_variable(xdg_directory::runtime_dir) == "XDG_RUNTIME_DIR");
+  }
+
+  SCENARIO("The values of the XDG variables depend on the environment", "[system][xdg][spec]")
+  {
+    auto const home_directory = std::filesystem::path{"/home/test"};
+    auto const run_directory = std::filesystem::path{"/run/user"};
+    auto const uid = std::to_string(::getuid());
+
+    GIVEN("An environment that only contains HOME")
+    {
+      auto home = "HOME="s + home_directory.native();
+      char const * env_data[] = {home.c_str(), nullptr};
+      auto env = environment{env_data};
+
+      THEN("the data home is '<home_directory>/.local/share")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::data_home, env) == home_directory / ".local/share");
+      }
+
+      THEN("the config home is '<home_directory>/.config")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::config_home, env) == home_directory / ".config");
+      }
+
+      THEN("the cache home is '<home_directory>/.cache")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::cache_home, env) == home_directory / ".cache");
+      }
+
+      THEN("the runtime directory is '<run_directory>/<uid>'")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::runtime_dir, env) == run_directory / uid);
+      }
+    }
+
+    GIVEN("An environment that only contains HOME and XDG_DATA_HOME")
+    {
+      auto home = "HOME="s + home_directory.native();
+      auto data_home = "XDG_DATA_HOME=/home/test/xdg_data_home"s;
+      char const * env_data[] = {home.c_str(), data_home.c_str(), nullptr};
+      auto env = environment{env_data};
+
+      THEN("the data home is '$XDG_DATA_HOME")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::data_home, env) == env["XDG_DATA_HOME"]);
+      }
+
+      THEN("the config home is '<home_directory>/.config")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::config_home, env) == home_directory / ".config");
+      }
+
+      THEN("the cache home is '<home_directory>/.cache")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::cache_home, env) == home_directory / ".cache");
+      }
+
+      THEN("the runtime directory is '<run_directory>/<uid>'")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::runtime_dir, env) == run_directory / uid);
+      }
+    }
+
+    GIVEN("An environment that only contains HOME and XDG_CONFIG_HOME")
+    {
+      auto home = "HOME="s + home_directory.native();
+      auto config_home = "XDG_CONFIG_HOME=/home/test/xdg_config_home"s;
+      char const * env_data[] = {home.c_str(), config_home.c_str(), nullptr};
+      auto env = environment{env_data};
+
+      THEN("the data home is '<home_directory>/.local/share")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::data_home, env) == home_directory / ".local/share");
+      }
+
+      THEN("the config home is '$XDG_CONFIG_HOME")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::config_home, env) == env["XDG_CONFIG_HOME"]);
+      }
+
+      THEN("the cache home is '<home_directory>/.cache")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::cache_home, env) == home_directory / ".cache");
+      }
+
+      THEN("the runtime directory is '<run_directory>/<uid>'")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::runtime_dir, env) == run_directory / uid);
+      }
+    }
+
+    GIVEN("An environment that only contains HOME and XDG_CACHE_HOME")
+    {
+      auto home = "HOME="s + home_directory.native();
+      auto cache_home = "XDG_CACHE_HOME=/home/test/xdg_cache_home"s;
+      char const * env_data[] = {home.c_str(), cache_home.c_str(), nullptr};
+      auto env = environment{env_data};
+
+      THEN("the data home is '<home_directory>/.local/share")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::data_home, env) == home_directory / ".local/share");
+      }
+
+      THEN("the cache home is '<home_directory>/.config")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::config_home, env) == home_directory / ".config");
+      }
+
+      THEN("the config home is '$XDG_CACHE_HOME")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::cache_home, env) == env["XDG_CACHE_HOME"]);
+      }
+
+      THEN("the runtime directory is '<run_directory>/<uid>'")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::runtime_dir, env) == run_directory / uid);
+      }
+    }
+
+    GIVEN("An environment that only contains HOME and XDG_RUNTIME_DIR")
+    {
+      auto home = "HOME="s + home_directory.native();
+      auto runtime_dir = "XDG_RUNTIME_DIR=/home/test/xdg_runtime_dir"s;
+      char const * env_data[] = {home.c_str(), runtime_dir.c_str(), nullptr};
+      auto env = environment{env_data};
+
+      THEN("the data home is '<home_directory>/.local/share")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::data_home, env) == home_directory / ".local/share");
+      }
+
+      THEN("the config home is '<home_directory>/.config")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::config_home, env) == home_directory / ".config");
+      }
+
+      THEN("the cache home is '<home_directory>/.cache")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::cache_home, env) == home_directory / ".cache");
+      }
+
+      THEN("the runtime directory is '$XDG_RUNTIME_DIR'")
+      {
+        REQUIRE(xdg_path_for(xdg_directory::runtime_dir, env) == env["XDG_RUNTIME_DIR"]);
+      }
+    }
+  }
+
+}  // namespace wanda::system::test
\ No newline at end of file