Develop Reference

Using google Test with Android NDK

gradle-ndk-gtest-sample
Android NDK with
README.NDK
I have been trying to configure my Android NDK project for use with Google Test. I started with native-activity sample as the base project and began following the guides above. I inserted the code from the first link into my root build.gradle. I am really not having any success. It looks like i was able to generate the test library:
./libs/googleTest/1.7.0/lib/osx/libgtest.a
./libs/googleTest/1.7.0/lib/linux/libgtest.a
./app/.externalNativeBuild/cmake/debug/x86_64/libnative_app_glue.a
./app/.externalNativeBuild/cmake/debug/x86_64/libFOO.a
./app/.externalNativeBuild/cmake/debug/x86_64/libgtest.a
./app/.externalNativeBuild/cmake/debug/arm64-v8a/libnative_app_glue.a
./app/.externalNativeBuild/cmake/debug/arm64-v8a/libFOO.a
./app/.externalNativeBuild/cmake/debug/arm64-v8a/libgtest.a
But I don't know where to go from here. How do I actually run the tests and see if they passed?

Try something like https://github.com/DanAlbert/GTestJNI. It's an alternative test runner for JUnit and GTest that exposes GTests as if they were JUnit, so you can just run your normal androidTests and they'll run your GTests for you.
Some day I want to get this either added to the NDK or at least made trivial to add to a project as a git submodule or something, but for now you can merge the pieces of that into your project.

Is it possible to analyze Android Kotlin code-coverage with SonarQube?

I have configured a Jenkins item that, after gradle building and testing, calls the "Execute SonarQube Scanner" with the following specifications:
sonar.projectKey=my_project_key
sonar.projectName=my_Android
sonar.projectVersion=1.0
sonar.sources=app/src
sonar.java.binaries=app/build/intermediates/classes/debug
sonar.coverage.exclusions=app/src/test/**,app/src/androidTest/**,app/src/main/res/**
This successfully runs SonarQube and generates a report to IPaddress:9000 that measures: Bugs, Vulnerabilities, Debt, Code Smells, and Duplications just like it is supposed to. However there is no place in this report that defines the code covered by tests. SonarQube is running the Kotlin plugin successfully and sees the codebase itself, but is not determining coverage. Is this possible to gather this information with SonarQube when using Kotlin Android?
I did try installing Jacoco, but did not see any new data on the SonarQube results.

You can install a 3rd-party Sonar plugin here that will measure code quality for Kotlin projects. Unfortunately, as of this posting, SonarQube does not have its own plugin for this.
Once that is set up, take a look here for setting up gradle and sonar-project.properties. The post is a little dated, but contains a link to an updated version and is still a good starting point.
TL;DR for #2: The information SonarQube needs for Kotlin is located in 2 places. One is already identified by the OP. The other is located in app/build/tmp/kotlin-classes.

If you are using gradle and Jacoco.
You can use Jacoco for the code coverage with the xmlReportPaths. With that Sonar will trust what Jacoco output.
sonarqube {
properties {
property("sonar.java.coveragePlugin", "jacoco")
property("sonar.coverage.jacoco.xmlReportPaths", "./build/reports/jacoco/test/jacocoTestReport.xml")
}
}
Documentation from Sonar + Jacoco Plugin.
It also works with mixed source code (Java, Kotlin).

I abandoned attempting to get Kotlin code coverage with Sonar shortly after posting the question.
However, I have gotten many projects to work with Java and JaCoCo.
Retrospectively looking back at my sonar.properties file I may have been able to fix this by referencing the output of the JaCoCo task by adding the following line to the sonar.properties file:
sonar.jacoco.reportPath=build/jacoco/test.exec
I am not sure that this will work with Kotlin, but it helped with Java coverage and solved my use case.

Newer versions of Sonarqube (6+) now support Kotlin natively, and do not require any custom configuration in your project.
Just ensure the Kotlin and the Jacoco plugins are installed, and it should just work for you.
--- OLD ANSWER---------------------------------
My project is using Jacoco for generating coverage reports.
To have SonarQube pick up the results, try setting the following:
sonar.java.binaries={$buildDir}/classes/kotlin
In other words let SonarQube know where the Kotlin class files are.
This configuration assumes a 100% Kotlin project. If your project is a mix of Java and Kotlin, then you'll have to determine how to configure both directories.

How can you add external dependencies to bazel

I am a student and currently working on a project where I am trying to connect my game that which I have created with Android Studio. A neural network has also been made with Tensorflow which is going to be used for the android game.
The problem is that Android Studio uses a build tool which is called Gradle and Tensorflow uses Bazel. To solve this problem I have been trying to build my android game with Bazel but I am stuck at the part where I have to add the used external dependencies. For the game I use the following dependencies:
Appcompat
Support
Percent
Which supposedly should come with the android support repository.
I have looked at http://www.bazel.io/docs/external.html and several other sources but I still do not understand how I can add the dependensies. Could someone provide me with an example how to do it with for example appcompat and what I have to do to make it work? Or is there another way which would be easier?
EDIT: I have have been succesful in building the android example of Tensorflow but this: https://github.com/tensorflow/tensorflow/tree/master/tensorflow/examples/android
But it doesn't include dependensies which I am using.

You may want to look at the Makefile support we just added for Android:
https://github.com/tensorflow/tensorflow/tree/master/tensorflow/contrib/makefile
It's still very experimental (and fiddly), but should let you build a static library that you can more easily use in your gradle project.

Nevermind I resolved my issues, after removing the depensies I checked the WORKSPACE file. It seems I didn't set the package correctly, my bad.

How to calculate test coverage while using Robolectric

I am using make for building and Robolectric as a framework for running Android tests. I would like to calculate coverage of my app. For instrumentation tests I used to use emmalib. What is the best way for me to set up coverage calculation in this case? I can't migrate to gradle or maven.

Are you bound to Emma? How about using RoboElectric + Cobertura code coverage? (I think you could just use a CLI for the above combination)
So options
1.) RoboElectric + Cobertura - CLI alone probably for someone not on ANT
2.) JaCoCo might have some useful options
3.) Pure Android Testing + Emma/EclEmma
Useful Link trails to follow
Generating android code coverage though changes in build.xml and ant.properties
Android Gradle Code Coverage
https://intellectualcramps.wordpress.com/2013/08/18/code-coverage-of-robolectric-tests-using-jacoco/
https://bitbucket.org/ravidsrk/androidstarter
EDIT:
Well most of the tutorials I have come across use ant unfortunately, and I don't think it would be a bad idea for you to move to a recommended build system like Gradle so it opens up a lot options. But for JaCoCo you could take a look at here: https://intellectualcramps.wordpress.com/2013/08/18/code-coverage-of-robolectric-tests-using-jacoco/
UPDATE:
Moved this from comments to the answer section for information to anyone wanting to see this and because this is a bounty question

One solution would be to use Cobertura to generate code coverage, which can be integrated in eclipse and also run by an ant build script.
A template project of such an integration can be found here: https://github.com/adgllorente/android-cobertura-boilerplate
Note that all of the magic happens in the build.xml of the Test project. Theses tasks should probably be generalised to a custom_rules.xml file so you can still use android to update your projects.
Finally, for Gradle you have many different options:
http://raptordigital.blogspot.nl/2014/08/code-coverage-reports-using-robolectric.html
http://chrisjenx.com/gradle-robolectric-jacoco-dagger/
https://stackoverflow.com/a/25037742/2771851
Note that you can always use Gradle as a secondary build system just to generate the coverage reports. (but a second build system will introduce a lot of overhead)

jacoco sometimes does not work with Robelectric and powermock runner you can use clover an atlassian tools it is now open source tool.

How to get code coverage in Android using Maven (android-maven-plugin)

I have an Android Maven project (let's call it parent_project) that contains various submodules: my_library_project, app_using_my_library_project, test_project and extra_lib.
So, the structure would be like this:
parent_project
* my_library_project (Android Library Project)
* app_using_my_library_project (Demo app that uses the Android Library Project)
* test_project (Project containing the tests instrumented against app_using_my_library_project)
* extra_lib
What I would like is to generate test coverage for my Android project using Maven (and not Ant, I am already able to generate code coverage reports using Ant, following these instructions: https://wiki.jenkins-ci.org/display/JENKINS/Building+an+Android+app+and+test+project).
I have no strong preference for the code coverage tool used but I would prefer EMMA, since seems the most common in the Android development world.
I am using android-maven-plugin (http://code.google.com/p/maven-android-plugin/) in its 3.0.0-alpha-12 version and I have already tried to put in the configuration of my parent's pom.xml the next:
<test>
<coverage>true</coverage>
<createreport>true</createreport>
</test>
But that does not produce the desired code coverage report.
So:
Is there any difference between the pom configuration for getting code coverage for a standard Java project and an Android project?
Do you know any example Android project using Maven that has code coverage?
Any hints on how to do this?

If you're going to stick with maven, and want a plugin for maven that will do the code-coverage job, I think Cobertura is a better choice, as Emma stable last build is from 2005.
Although in "Android Application Testing Guide" (a recent book from June this year) they talk about Emma and demonstrate how to use it for testing, I think people stick to it, because it's needed to build Android from source (and if Google use it for their own OS development, it should be the best, right?).
If you're not fanatically bound to Maven, I strongly recommend to try Robotium.
Robotium has full support for Activities, Dialogs, Toasts, Menus, and Context Menus.
It also supports code coverage (Ant based though, for now) and some people recognize it as one of the leading testing platforms for Android.
Edit:
According to the Cobertura site, it supports code coverage in Maven 1 and Maven 2 environments. Although, you can find examples with Maven 3 also.
A problem exists between pom configurations of Maven 2 and Maven 3. It seems for the reporting to work you have to basically move your old reporting plugins into the configuration section of the new maven-site-plugin. (See the article for details).
Another option is to try and use Sonar with Maven. Sonar has cobertura embedded (also options to embedd EMMA) and some people state that they had successfully reported code coverage, despite they had problems using the "stand-alone" cobertura plugin.

I could generate code coverage reported using emma maven plugin and display reports in sonar for an android application project. Just follow the configuration in https://code.google.com/p/maven-android-plugin/wiki/EmmaMaven.
But for library project I get a 0% coverage. It doesn't generate the metadata files. However as soon I change the library project to package as an apk, it works like a charm. It runs the tests in a emulator(configured in jenkins) and shows the coverage reports.
If you are looking out specifically for library project, this wont help. I will post if I find some solution which deals with library projects.