gtest: Added Google Test

Added Google Test for unit testing.  Currently NOT required by UPM
CMake.

    * Added a test fixture for the utilities library.
    * Fixed bug in delay methods provided by utilities library.

Signed-off-by: Noel Eck <noel.eck@intel.com>

src/utilities/upm_utilities.c

@@ -52,8 +52,9 @@ static struct aqi {
 
 void upm_delay(unsigned int time)
 {
-    if (time <= 0)
+    /* Return if time == 0 */
-        time = 1;
+    if (!time)
+        return;
 
 #if defined(UPM_PLATFORM_LINUX)
 
@@ -92,8 +93,9 @@ void upm_delay(unsigned int time)
 
 void upm_delay_ms(unsigned int time)
 {
-    if (time <= 0)
+    /* Return if time == 0 */
-        time = 1;
+    if (!time)
+        return;
 
 #if defined(UPM_PLATFORM_LINUX)
 
@@ -128,8 +130,9 @@ void upm_delay_ms(unsigned int time)
 
 void upm_delay_us(unsigned int time)
 {
-    if (time <= 0)
+    /* Return if time == 0 */
-        time = 1;
+    if (!time)
+        return;
 
 #if defined(UPM_PLATFORM_LINUX)
 

tests/CMakeLists.txt

@@ -82,3 +82,6 @@ endif (BUILDSWIGPYTHON AND PYTHON3INTERP_FOUND)
 #        -DUPMBASEDIR=${CMAKE_SOURCE_DIR}
 #        -P ${CMAKE_SOURCE_DIR}/tests/runjsontest.cmake)
 #endif(NPM_EXECUTABLE)
+
+# Unit tests
+add_subdirectory (unit)

tests/unit/CMakeLists.txt

@@ -0,0 +1,12 @@
+# For now, Google Test is NOT required */
+find_package(GTest)
+
+# If not found, print a status message and return
+if(NOT GTEST_FOUND)
+    message(STATUS "Install Google Test to enable additional unit testing")
+    return ()
+endif()
+
+add_executable(utilities_tests utilities/utilities_tests.cxx)
+target_link_libraries(utilities_tests utilities GTest::GTest GTest::Main)
+gtest_add_tests(utilities_tests "" AUTO)

tests/unit/utilities/utilities_tests.cxx

@@ -0,0 +1,70 @@
+#include "gtest/gtest.h"
+#include "upm_utilities.h"
+#include "upm_utilities.hpp"
+
+/* Utilities test fixture */
+class utilities_unit : public ::testing::Test
+{
+    protected:
+        /* One-time setup logic if needed */
+        utilities_unit() {}
+
+        /* One-time tear-down logic if needed */
+        virtual ~utilities_unit() {}
+
+        /* Per-test setup logic if needed */
+        virtual void SetUp() {}
+
+        /* Per-test tear-down logic if needed */
+        virtual void TearDown() {}
+};
+
+/* Test the second delay method */
+TEST_F(utilities_unit, test_upm_delay)
+{
+    upm_clock_t clock;
+    upm_clock_init(&clock);
+
+    /* Test a corner case */
+    upm_delay(0);
+    upm_delay(1);
+
+    /* +- check for 1s +/- 1ms */
+    ASSERT_NEAR(upm_elapsed_ms(&clock), 1000, 1);
+}
+
+/* Test the millisecond delay method */
+TEST_F(utilities_unit, test_upm_delay_ms)
+{
+    upm_clock_t clock;
+    upm_clock_init(&clock);
+
+    /* Test a corner case */
+    upm_delay_ms(0);
+    upm_delay_ms(50);
+
+    /* +- check for 50ms +/- 1ms */
+    ASSERT_NEAR(upm_elapsed_ms(&clock), 50, 1);
+}
+
+/* Test the microsecond delay method */
+TEST_F(utilities_unit, test_upm_delay_us)
+{
+    upm_clock_t clock;
+    upm_clock_init(&clock);
+
+    /* Test a corner case */
+    upm_delay_us(0);
+    upm_delay_us(1000);
+
+    /* +- check for 1000us +/- 100us */
+    ASSERT_NEAR(upm_elapsed_us(&clock), 1000, 100);
+}
+
+/* Currently no need for a custom main (use gtest's)
+int main(int argc, char **argv)
+{
+    ::testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS();
+}
+*/