Running C++ Unit Tests on Android devices

This tutorial shows how to run C++ unit tests on your Android devices. We will create a basic unit test based on the CppUTest framework that will check that the device has an accelerometer.

Before you begin, install VisualGDB 5.2 or later.

1. Start Visual Studio and open the VisualGDB Android Project Wizard:
2. On the first page of the wizard select “Create a unit test project” and pick a framework. VisualGDB supports CppUTest and Googletest out-of-the-box and provides an extensibility interface to support any other 3rd-party framework:Normally VisualGDB will create  Java app with C++ code that will run the unit tests inside a separate thread. If you don’t need the App context, you can select “Run tests inside a command-line executable” to create a stand-alone command-line Android binary.
3. Proceed with the default settings on the “Project Source” page:
4. On the last page of the wizard select the platform you would like to target and the hardware platforms:
5. Press “Finish” to generate the project. Build it with Ctrl-Shift-B and open the Test Explorer to see the example unit tests detected by Visual Studio:
6. Select Test->Run All to launch them on your device. The FailingTest should immediately fail, while the others should succeed:
7. Now we will add a basic tests that ensures that your device has an accelerometer. Replace the code in the tests file with the following:

   #include <CppUTest/CommandLineTestRunner.h> #include <stdio.h> #include <android/sensor.h>   TEST_GROUP(HardwareTests) { };   TEST(HardwareTests, AccelerometerTest) {     ASensorList sensorList;     ASensorManager* sensorManager = ASensorManager_getInstance();     CHECK(sensorManager);     int n = ASensorManager_getSensorList(sensorManager, &sensorList);     bool accelerometerFound = false;     for (int i = 0; i < n; i++)     {         const ASensor* sensor = sensorList[i];         if (sensor == NULL)             continue;         if (ASensor_getType(sensor) != ASENSOR_TYPE_ACCELEROMETER)             continue;           const char* name = ASensor_getName(sensor);         const char* vendor = ASensor_getVendor(sensor);         printf("Found accelerometer: %s %s\n", vendor, name);         accelerometerFound = true;     }          CHECK(accelerometerFound); }

   #include <CppUTest/CommandLineTestRunner.h> #include <stdio.h> #include <android/sensor.h> TEST_GROUP(HardwareTests) { }; TEST(HardwareTests, AccelerometerTest) {     ASensorList sensorList;     ASensorManager* sensorManager = ASensorManager_getInstance();     CHECK(sensorManager);     int n = ASensorManager_getSensorList(sensorManager, &sensorList);     bool accelerometerFound = false;     for (int i = 0; i < n; i++)     {         const ASensor* sensor = sensorList[i];         if (sensor == NULL)             continue;         if (ASensor_getType(sensor) != ASENSOR_TYPE_ACCELEROMETER)             continue;         const char* name = ASensor_getName(sensor);         const char* vendor = ASensor_getVendor(sensor);         printf("Found accelerometer: %s %s\n", vendor, name);         accelerometerFound = true;     }          CHECK(accelerometerFound); }

8. Add “-landroid” to the System Library Names field in VisualGDB Project Properties so that your project can use the ASensor_xxx() functions:
9. Build the project. The Test Explorer window will show the newly added test:
10. Start it via Test->Run All Tests or by right-clicking on it and selecting “Run Selected Tests”:
11. If your device has an accelerometer, the test should succeed. If it does not, you can easily debug it by right-clicking on it in Test Explorer and selecting “Debug selected tests”:
12. You can use the Call Stack window to understand the context in which the test is run. VisualGDB creates a separate thread using the pthread_create() function and passes control to the CppUTest framework. VisualGDB automatically selects the tests to run and interprets the information about successful and failed runs:
13. VisualGDB also generates a very basic Java source file that creates a simple activity and invokes the StartTests() function so that the native tests can be started: