examples: rfnoc-gain: Add unit tests

Co-authored-by: Jörg Hofrichter <joerg.hofrichter@emerson.com>

host/examples/rfnoc-gain/CMakeLists.txt

@@ -68,6 +68,17 @@ else()
     message(WARNING "UHD not found. Cannot build block controllers.")
 endif()
 
+###########################################################################
+# Find Boost
+###########################################################################
+# This matches the required Boost version with the one from UHD; if you
+# require a different version, you can manually specify it here.
+include(UHDMinDepVersions)
+find_package(Boost ${UHD_BOOST_MIN_VERSION}
+    OPTIONAL_COMPONENTS unit_test_framework)
+include(UHDUnitTest OPTIONAL RESULT_VARIABLE HAVE_UHD_UNIT_TEST_FRAMEWORK)
+
+
 ###########################################################################
 # Find Python and uhd Python module
 ###########################################################################
@@ -217,3 +228,8 @@ endif()
 if(ENABLE_PYTHON_API)
     add_subdirectory(python)
 endif()
+if(HAVE_UHD_UNIT_TEST_FRAMEWORK AND Boost_UNIT_TEST_FRAMEWORK_FOUND)
+    message(STATUS "Boost unit test framework found, enabling tests.")
+    enable_testing()
+    add_subdirectory(tests)
+endif()

host/examples/rfnoc-gain/tests/CMakeLists.txt

@@ -0,0 +1,58 @@
+#
+# Copyright 2025 Ettus Research, a National Instruments Brand
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+
+########################################################################
+# unit test support
+########################################################################
+include(UHDUnitTest)
+
+########################################################################
+# unit test suite
+########################################################################
+set(test_sources
+    gain_math_test.cpp
+    gain_block_test.cpp
+)
+########################################################################
+# Setup the include paths
+########################################################################
+include_directories(
+    ${CMAKE_SOURCE_DIR}/lib
+    ${CMAKE_SOURCE_DIR}/include
+    ${CMAKE_BINARY_DIR}/lib
+    ${CMAKE_BINARY_DIR}/include
+    ${UHD_INCLUDE_DIRS}
+    ${Boost_INCLUDE_DIR}
+)
+
+# Note: Python-based tests cannot have the same name as a C++-based test (i.e.,
+# only differ in the cpp/py file extension). If in doubt, prepend 'py'.
+#set(pytest_sources
+#)
+
+#turn each test cpp file into an executable with an int main() function
+add_definitions(-DBOOST_TEST_DYN_LINK -DBOOST_TEST_MAIN)
+
+#for each source: build an executable, register it as a test
+foreach(test_source ${test_sources})
+    get_filename_component(test_name ${test_source} NAME_WE)
+    add_executable(${test_name} ${test_source})
+    target_link_libraries(${test_name} uhd rfnoc-gain ${Boost_LIBRARIES})
+    UHD_ADD_TEST(${test_name} ${test_name})
+    install(TARGETS ${test_name} RUNTIME DESTINATION ${CMAKE_INSTALL_LIBDIR}/tests COMPONENT tests)
+endforeach(test_source)
+
+if(ENABLE_PYTHON_API)
+    foreach(test_source ${pytest_sources})
+        get_filename_component(test_name ${test_source} NAME_WE)
+        UHD_ADD_PYTEST(${test_name})
+    endforeach(test_source)
+    install(FILES ${pytest_sources}
+        DESTINATION ${CMAKE_INSTALL_LIBDIR}/tests
+        COMPONENT tests
+    )
+endif(ENABLE_PYTHON_API)
+

host/examples/rfnoc-gain/tests/gain_block_test.cpp

@@ -0,0 +1,86 @@
+//
+// Copyright 2019 Ettus Research, a National Instruments Brand
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+//
+
+#include <uhd/rfnoc/actions.hpp>
+#include <uhd/rfnoc/defaults.hpp>
+#include <uhd/rfnoc/detail/graph.hpp>
+#include <uhd/rfnoc/mock_block.hpp>
+#include <uhd/rfnoc/mock_nodes.hpp>
+#include <uhd/rfnoc/node_accessor.hpp>
+#include <uhd/rfnoc/register_iface_holder.hpp>
+#include <rfnoc/gain/gain_block_control.hpp>
+#include <boost/test/unit_test.hpp>
+#include <iostream>
+#include <memory>
+
+using namespace uhd::rfnoc;
+using namespace rfnoc::gain;
+using namespace uhd::rfnoc::test;
+
+// Redeclare this here, since it's only defined outside of UHD_API
+noc_block_base::make_args_t::~make_args_t() = default;
+
+constexpr size_t NUM_CHANS = 1;
+
+/*
+ * gain_block_fixture is a class which is instantiated before each test
+ * case is run. It sets up the block container, gain_block_control
+ * object and node accessor, all of which are accessible to the test case.
+ * The instance of the object is destroyed at the end of each test case.
+ */
+struct gain_block_fixture
+{
+    gain_block_fixture()
+        : block_container(
+            get_mock_block(0xb16, NUM_CHANS, NUM_CHANS, uhd::device_addr_t()))
+        , test_gain(block_container.get_block<gain_block_control>())
+    {
+        node_accessor.init_props(test_gain.get());
+    }
+
+    mock_block_container block_container;
+    std::shared_ptr<gain_block_control> test_gain;
+    // The node_accessor is a C++ construct to bypass the public/private
+    // division of the underlying C++ class. This should never be used in
+    // production outside of unit tests, but here, it lets us peek inside the
+    // class to verify it's working as expected.
+    node_accessor_t node_accessor{};
+};
+
+/*
+ * The block controller doesn't do much but constrain its edge type properties
+ * to what the block expects (sc16 in; s32 out). This test ensures that a
+ * log power block in a graph will propagate its expected types to the
+ * source and sink connected to it.
+ */
+BOOST_FIXTURE_TEST_CASE(gain_test_edge_types, gain_block_fixture)
+{
+    detail::graph_t graph{};
+
+    mock_terminator_t mock_source_term(NUM_CHANS);
+    mock_terminator_t mock_sink_term(NUM_CHANS);
+
+    constexpr size_t chan = 0;
+
+    UHD_LOG_INFO("TEST", "Creating graph...");
+    detail::graph_t::graph_edge_t edge_info{
+        chan, chan, detail::graph_t::graph_edge_t::DYNAMIC, true};
+    graph.connect(&mock_source_term, test_gain.get(), edge_info);
+    graph.connect(test_gain.get(), &mock_sink_term, edge_info);
+
+    UHD_LOG_INFO("TEST", "Committing graph...");
+    graph.commit();
+    UHD_LOG_INFO("TEST", "Commit complete.");
+
+    // Check if we can use the C++ API to set the gain, then read it back via
+    // the property interface
+    test_gain->set_gain_value(10);
+    BOOST_CHECK_EQUAL(
+        test_gain->get_property<int>(gain_block_control::PROP_KEY_GAIN), 10);
+    // Now flip it: Write the property, and read back from the C++ API
+    test_gain->set_property<int>(gain_block_control::PROP_KEY_GAIN, 20);
+    BOOST_CHECK_EQUAL(test_gain->get_gain_value(), 20);
+}

host/examples/rfnoc-gain/tests/gain_math_test.cpp

@@ -0,0 +1,18 @@
+//
+// Copyright 2025 Ettus Research, a National Instruments Brand
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+//
+
+#include <boost/test/unit_test.hpp>
+#include <cstdint>
+#include <iostream>
+
+// This is a simple test, purely for demonstration purposes.
+BOOST_AUTO_TEST_CASE(gain_math_test)
+{
+    int x = 5;
+    int g = 10;
+
+    BOOST_CHECK_EQUAL(x * g, 50);
+}