Add Linux consumer tests; remove discovery probe

Replace external discovery-based tests with in-process consumer integration tests that validate virtual devices via SDL2 and libinput. Added tests/unit/test_linux_consumers.cpp and updated tests/CMakeLists.txt to use pkg-config and link PkgConfig::LIBINPUT and PkgConfig::SDL2. Removed the linux_discovery_probe example and the legacy tests/unit/test_linux_discovery.cpp, and cleaned up examples/CMakeLists.txt. Updated README to document the new Linux test requirements (SDL2, libinput, device nodes, X11/XTest where applicable) and adjusted CI (.github/workflows/ci.yml) to install libinput-dev, libsdl2-dev and pkg-config instead of the old joystick package.

Author: ReenigneArcher

.github/workflows/ci.yml

@@ -78,19 +78,38 @@ jobs:
             build-essential \
             clang \
             cmake \
-            joystick \
+            libinput-dev \
+            libsdl2-dev \
             libx11-dev \
             libxtst-dev \
             llvm \
-            ninja-build
+            ninja-build \
+            pkg-config
+          kernel_modules_package="linux-modules-extra-$(uname -r)"
+          if apt-cache show "${kernel_modules_package}" >/dev/null 2>&1; then
+            sudo apt-get install -y "${kernel_modules_package}"
+          else
+            echo "::warning::${kernel_modules_package} is unavailable; relying on the runner image kernel modules."
+          fi
           sudo tee /etc/udev/rules.d/99-libvirtualhid-ci.rules >/dev/null <<'EOF'
           KERNEL=="hidraw*", ATTRS{name}=="libvirtualhid*", MODE="0666", TAG+="uaccess"
           SUBSYSTEMS=="input", ATTRS{name}=="libvirtualhid*", MODE="0666", TAG+="uaccess"
           EOF
           sudo udevadm control --reload-rules
-          sudo modprobe uhid
-          sudo modprobe uinput
-          sudo chmod a+rw /dev/uhid /dev/uinput
+          for module in uhid uinput; do
+            if ! sudo modprobe "${module}"; then
+              message="Unable to load ${module}; tests requiring /dev/${module} will fail unless the device already exists."
+              echo "::warning::${message}"
+            fi
+          done
+          for node in /dev/uhid /dev/uinput; do
+            if [[ -e "${node}" ]]; then
+              sudo chmod a+rw "${node}"
+            else
+              echo "::error::${node} does not exist after module setup."
+              exit 1
+            fi
+          done
 
       - name: Setup Dependencies macOS
         if: runner.os == 'macOS'

README.md

@@ -153,14 +153,11 @@ current user cannot open `/dev/uhid`.
 The Linux uinput smoke test creates real keyboard and mouse devices and fails
 when the current user cannot open `/dev/uinput`.
 
-The Linux discovery integration test creates a real UHID gamepad and probes
-external input discovery tools. It fails when `/dev/uhid` is unavailable, or
-when neither `evdev-joystick` from the `joystick` package nor `hidapitester` is
-installed.
-
-When `BUILD_EXAMPLES` is enabled on Linux, the `linux_discovery_probe` example
-creates a generic UHID gamepad and performs the same external discovery probe
-outside the test runner.
+The Linux consumer integration tests create real virtual devices and validate
+them through in-process consumer libraries. SDL2 must see the UHID gamepad and
+observe button/axis input. libinput must see the uinput keyboard and mouse and
+observe key, pointer motion, and button events. These tests fail when the Linux
+device nodes or consumer development libraries are unavailable.
 
 The XTest fallback should not be treated as a gamepad backend. It can cover
 keyboard and mouse injection on X11, but it does not create virtual HID devices,
@@ -273,8 +270,8 @@ the requirements expressed in terms that apply to other consumers:
 - [x] Keep the public headers under `include/libvirtualhid` and the implementation
   split into shared core code plus platform-specific backends.
 - [x] Add Windows CI coverage for the client library with MSVC and MinGW/UCRT64.
-- [x] Add Linux CI coverage for GCC and Clang, with integration tests gated behind
-  explicit availability of `/dev/uinput`, `/dev/uhid`, or X11/XTest.
+- [x] Add Linux CI coverage for GCC and Clang, with integration tests requiring
+  `/dev/uinput`, `/dev/uhid`, SDL2, libinput, and X11/XTest where applicable.
 - [ ] Add separate WDK/MSVC validation for the driver package once driver sources
   exist.
 
@@ -326,8 +323,8 @@ third-party/googletest/       GoogleTest submodule
 - [x] Add `uinput` support for keyboard and mouse once the gamepad path is stable.
 - [x] Support output report callbacks for rumble and profile-specific feedback.
 - [x] Add X11/XTest fallback support for keyboard and mouse only.
-- [x] Add examples and integration tests that validate external gamepad
-  discovery where available.
+- [x] Add examples and integration tests that validate virtual device visibility
+  through SDL2 for gamepads and libinput for keyboard/mouse.
 - [x] Document required Linux permissions and sample udev rules.
 
 ### Phase 3: Windows MVP
@@ -368,7 +365,7 @@ third-party/googletest/       GoogleTest submodule
 - [ ] Validate multi-controller behavior and stable ordering.
 - [ ] Test against real consumers where practical: Sunshine, SDL, HIDAPI, browser
   Gamepad API, DirectInput/XInput/GameInput on Windows, and evdev/libinput
-  tooling on Linux.
+  libraries on Linux.
 
 ## License
 

examples/CMakeLists.txt

@@ -14,12 +14,3 @@ target_link_libraries(keyboard_mouse_adapter
 
 libvirtualhid_copy_mingw_runtime(gamepad_adapter)
 libvirtualhid_copy_mingw_runtime(keyboard_mouse_adapter)
-
-if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
-    add_executable(linux_discovery_probe
-      "${CMAKE_CURRENT_SOURCE_DIR}/linux_discovery_probe.cpp")
-
-    target_link_libraries(linux_discovery_probe
-      PRIVATE
-      libvirtualhid::libvirtualhid)
-endif()

examples/linux_discovery_probe.cpp

@@ -39,6 +39,11 @@
   #include <X11/keysym.h>
   #include <X11/Xlib.h>
   #include <X11/Xutil.h>
+
+  // Xlib defines Status as a macro, which collides with lvh::Status.
+  #if defined(Status)
+    #undef Status
+  #endif
 #endif
 
 // local includes

src/platform/linux/uhid_backend.cpp

@@ -18,12 +18,16 @@ set(LIBVIRTUALHID_TEST_SOURCES
   "${CMAKE_CURRENT_SOURCE_DIR}/fixtures/fixtures.cpp"
   "${CMAKE_CURRENT_SOURCE_DIR}/unit/test_gamepad_lifecycle.cpp"
   "${CMAKE_CURRENT_SOURCE_DIR}/unit/test_linux_backend.cpp"
-  "${CMAKE_CURRENT_SOURCE_DIR}/unit/test_linux_discovery.cpp"
+  "${CMAKE_CURRENT_SOURCE_DIR}/unit/test_linux_consumers.cpp"
   "${CMAKE_CURRENT_SOURCE_DIR}/unit/test_profiles.cpp"
   "${CMAKE_CURRENT_SOURCE_DIR}/unit/test_report.cpp"
   "${CMAKE_CURRENT_SOURCE_DIR}/unit/test_runtime.cpp")
 
 if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
+    find_package(PkgConfig REQUIRED)
+    pkg_check_modules(LIBINPUT REQUIRED IMPORTED_TARGET libinput)
+    pkg_check_modules(SDL2 REQUIRED IMPORTED_TARGET sdl2)
+
     list(APPEND LIBVIRTUALHID_TEST_SOURCES
          "${CMAKE_CURRENT_SOURCE_DIR}/fixtures/linux_backend_test_hooks.cpp")
 
@@ -45,6 +49,13 @@ target_link_libraries(${TEST_BINARY}
   gmock_main
   libvirtualhid::libvirtualhid)
 
+if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
+    target_link_libraries(${TEST_BINARY}
+      PRIVATE
+      PkgConfig::LIBINPUT
+      PkgConfig::SDL2)
+endif()
+
 if(CMAKE_SYSTEM_NAME STREQUAL "Linux" AND LIBVIRTUALHID_ENABLE_XTEST AND X11_FOUND AND X11_XTest_FOUND)
     target_compile_definitions(${TEST_BINARY}
       PRIVATE