tests: Add infrastructure to run Python unit tests

- Add UHD_ADD_PYTEST() CMake macro
- Add CMake code to tests/CMakeLists.txt to auto-run all registered
  Python unit tests
- Add a token unit test (it replicates parts of ranges_test.cpp)

The way Python-based unit tests are implemented in UHD is that they can
import uhd, and then operate on the module as usual.

Writing unit tests in Python instead of C++ can have multiple
advantages:
- If they test PyBind-wrapped C++ code, they can test both the binding
  and the underlying C++ code at once
- Writing unit tests in Python may be more concise

1 files changed, 12 insertions, 0 deletions

diff --git a/host/cmake/Modules/UHDUnitTest.cmake b/host/cmake/Modules/UHDUnitTest.cmake
index 9a71ca2aa..f1f52addc 100644
--- a/host/cmake/Modules/UHDUnitTest.cmake
+++ b/host/cmake/Modules/UHDUnitTest.cmake
@@ -104,3 +104,15 @@ function(UHD_ADD_TEST test_name)
     endif(WIN32)
 
 endfunction(UHD_ADD_TEST)
+
+########################################################################
+# Add a Python unit test
+########################################################################
+function(UHD_ADD_PYTEST test_name)
+    add_test(NAME ${test_name}
+        COMMAND ${RUNTIME_PYTHON_EXECUTABLE} -m unittest discover
+                                             -s ${CMAKE_CURRENT_SOURCE_DIR}
+                                             -p "${test_name}.*"
+        WORKING_DIRECTORY "${CMAKE_BINARY_DIR}/python"
+    )
+endfunction(UHD_ADD_PYTEST)