Code Coverage for C & CPP Apps in Android Studio IDE
How to Integrate RKTracer with Android Studio IDE and generate code coverage
How to Integrate RKTracer plugin in Android Studio in Windows 10/Linux?
Step 1: Open Android Studio IDE.
Step 2: Go to the File menu→ Settings → Plugin on the left side of the screen and then on the right side, click the “setting” icon on the right side and select the “install plug-in from disk” option.
Step 3: Navigate to the RKTracer tool installation folder,
Select “RKTracer-Android-Plugin.jar” and select ok, to install the RKTracer plugin for Android Studio IDE.
Step 4: Now, we need to restart the android studio IDE. You should see RKTracer options under the Tools menu → The RKtracer option to turn ON or OFF or generate reports. There is also a quick turn ON/OFF option with a click mark in green color, as shown in the below screenshot.
How to generate Code coverage for application in android studio IDE?
Following Instructions will work for all the Apps with C/C++ or Java, or Kotlin, or in combination in Android Studio IDE. Ensure that you can build and test the app in android studio or on the phone device.
Step 1: Enable RKTracer Tool.
Goto → Tools→ RKTracer and select Switch Instrumentation ON.
Step 2: Rebuild the application.
You need to rebuild the app in android studio ide to the instrument with the RKTracer tool as instrumentation takes place at a source code level.
Step 3: Install the APK in the device
Don’t disconnect the device from the host machine. Execute the following command by opening the command prompt or terminal from the project directory, i.e., parallel to the rktracer folder(rktracer folder will get generate at the build/instrument time of application with the rktracer tool). So that coverage data from logcat will get collected from the device. Then start testing the app on the device.
adb -e logcat > rk-coverage.txt 2>&1
The above command will write code coverage data from logcat to the rk-coverage.txt file. You should not change the file name, i.e., rk-coverage.txt as the RKTracer tool will consider the rk-coverage.txt file as a coverage data file. By default, the rktracer tool will save coverage data in the phone device, you check this in logcat output. Here is the sample logcat output for the keyword “rk-coverage.”
2021-05-19 20:17:39.947 1203-4189/com.google.android.gms I/SQLiteCastStore: [CastNetworkInfo] saved: 0, skipped: 0, [CastDeviceInfo]: saved 0, skipped 1, [Paired Guest Mode DeviceInfo] saved: 0, skipped: 0. [ProbedNetworks]: saved 0, skipped: 0, [ProbedSocketAddress]: saved 0, skipped: 0, [Network-Device pairs]: saved: 0
2021-05-19 20:17:58.173 4718-4753/? I/rktracer: ‘/sdcard/rk-coverage.txt’ Operation not permitted
2021-05-19 20:17:58.174 4718-4753/? I/rktracer: writing to ‘/data/data/com.example.widecolor/rk-coverage.txt’
2021-05-19 20:26:39.240 5053-5084/? I/rktracer: ‘/sdcard/rk-coverage.txt’ Operation not permitted
2021-05-19 20:26:39.241 5053-5084/? I/rktracer: writing to ‘/data/data/com.example.widecolor/rk-coverage.txt’
2021-05-19 20:27:39.428 5181-5207/? I/rktracer: ‘/sdcard/rk-coverage.txt’ Operation not permitted
2021-05-19 20:27:39.428 5181-5207/? I/rktracer: writing to ‘/data/data/com.example.widecolor/rk-coverage.txt’
To pull the coverage data, you can execute the command.
adb pull /data/data/com.example.widecolor/rk-coverage.txt
We need to copy the pulled rk-coverage.txt file to the application folder where we have the rktracer folder in the application directory.
Step 4:Generate Code Coverage Report
We can either use the Tools menu → rktracer → Generate Report option to generate a code coverage report or open a terminal or command prompt in the application directory where have the rktracer folder and execute the following command to generate reports.
Linux: “rkresults app/build.gradle” to generate reports.
Windows: “rkresults app\build.gradle” to generate reports.
If the RKTracer Html reports are not opening in the browser, we can navigate the project folder/rktracer/reports/ and open index.html to check the reports.
NOTE: Once the reports are generated, you need to Turn OFF the RKTracer tool. go to Tools menu -> rktracer -> Switch Instrumentation Off
In case if your not connected to the device and wants to pull coverage data from the phone device and your not able to find the rk-coverage.txt file.
Coverage data file not found after testing.
RKTracer tool uses the following approaches to save coverage data.
- Run unit/functional testing, and at the end RKTracer tool will automatically save coverage data on the host/embedded target/server machine, that is, write coverage data to the rk-coverage.txt file.
- Send a signal to the application running in an infinite loop to trigger and save coverage data.
- The application under test has crashed in the middle of testing on the host or target device. RKTracer saves coverage data to rk-coverage.txt and generate reports to check the point of a crash in reports.
- Embedded devices without a file system or not connected to host while testing. In this case, rktracer RAW mode comes in to picture. You need to save the coverage data from the RKTracer variable.
Suppose you cannot find the rk-coverage.txt file in the project working folder or target server machine. An application under test has not exited with the proper exit handler, i.e., atexit() handler, or your application might be running in an infinite loop. You can use the following two methods to save coverage data from memory to the file system.
Save coverage data when a particular function is executed at runtime testing.
Identify a function/method name in your application (ensure this function/method is not excluded from RKTracer instrumentation or file with this function). Then copy the function name and edit the rktracer.config in the RKTracer installation folder.
For C programming language: Add a new line at the end of rktracer.config file with “c-function-writeout” and function name. Here the function name is case sensitive, and you should also add empty braces, i.e., () at the end of a function name. In case if you have a function with an input parameter, it should still be empty braces. You can add multiple function names with one space to the list, as shown below.
- c-function-writeout main()
- c-function-writeout main() OnCreate() fun()
For C++ programming language: Add a new line at the end of rktracer.config file with “c++-function-writeout” and function name. Here the function name is case sensitive, and you should also add empty braces, i.e., () at the end of a function name. In case if you have a function with an input parameter, it should still be empty braces. You can add multiple function names with one space to the list, as shown below.
- c++-function-writeout main()
- c++-function-writeout main() OnCreate() fun()
After adding function name to rktracer.config file. You need to rebuild the application to re-instrument using rktracer. Coverage data will be saved to the rk-coverage.txt file when this function executes at runtime testing.
Send a signal to save coverage data.
We can send a signal to the application running in an infinite loop to save coverage data to rk-coverage.txt.
- Windows: send a kill signal using keys in the keyboard, i.e., Control+Pause/break. Contact support if you would like to add additional signal command to save coverage data at runtime testing.
- Linux/Unix: Send a SIGWINCH signal: killall -SIGWINCH a.out or kill -SIGWINCH Process ID number.
Generate code coverage for selected functions/files/folder
Generate coverage reports for the selected folders
Suppose you need code coverage for source files from three different folders, i.e., core, keys, power, and ignore coverage for folders firmware_loader and lockdown. Edit rktracer.config in the RKTracer installation folder and go to the end of the file add the following information.
instrument */power/* */core/* */keys/*
never */firmware_loader/* */lockdown/*
ignore *.c = Ignores all C source files from instrumentation
Instrument = Instrument source files from given folders
never = ignore selected folder
Generate coverage reports only for selected functions from three different files.
fun_X() in source-file-X
fun_Y() in source-file-Y
fun_Z() in source-file-Z
Suppose you need code coverage for selected functions from three different files. Edit rktracer.config in the RKTracer installation folder and go to the end of the file and set the following variables as shown below.
instrument *source-file-X.c *source-file-Y.c *source-file-Z.c
function-instrument fun_X() fun_Y() fun_Z()
ignore *.c = Ignore all C programming source files
instrument *file-X.c *file-Y.c *file-Z.c = Instrument only these three source files.
function-ignore * = Then ignore all functions in the above three files.
function-instrument fun_X() fun_Y() fun_Z() = Don’t ignore these three functions from these three files from instrumentation.