testing-android.md

Testing Libraries on Android

Prerequisites

The following dependencies should be installed in order to be able to run tests:

• OpenJDK
• Android NDK
• Android SDK

To manage the dependencies, you can install them via terminal or using Android Studio.

Using a terminal

OpenJDK can be installed on Linux (Ubuntu) using apt-get:

sudo apt-get install openjdk-8 zip unzip

Android SDK and NDK can be automatically installed via the following script:

#!/usr/bin/env bash
set -e

NDK_VER=r21b
SDK_VER=6200805_latest
SDK_API_LEVEL=29
SDK_BUILD_TOOLS=29.0.3

if [[ "$OSTYPE" == "darwin"* ]]; then
    HOST_OS=darwin
    HOST_OS_SHORT=mac
    BASHRC=~/.zprofile
else
    HOST_OS=linux
    HOST_OS_SHORT=linux
    BASHRC=~/.bashrc
fi

# download Android NDK
export ANDROID_NDK_ROOT=~/android-ndk-${NDK_VER}
curl https://dl.google.com/android/repository/android-ndk-${NDK_VER}-${HOST_OS}-x86_64.zip -L --output ~/andk.zip
unzip ~/andk.zip -d $(dirname ${ANDROID_NDK_ROOT}) && rm -rf ~/andk.zip

# download Android SDK, accept licenses and download additional packages such as
# platform-tools, platforms and build-tools
export ANDROID_SDK_ROOT=~/android-sdk
curl https://dl.google.com/android/repository/commandlinetools-${HOST_OS_SHORT}-${SDK_VER}.zip -L --output ~/asdk.zip
mkdir ${ANDROID_SDK_ROOT} && unzip ~/asdk.zip -d ${ANDROID_SDK_ROOT}/cmdline-tools && rm -rf ~/asdk.zip
yes | ${ANDROID_SDK_ROOT}/cmdline-tools/tools/bin/sdkmanager --sdk_root=${ANDROID_SDK_ROOT} --licenses
${ANDROID_SDK_ROOT}/cmdline-tools/tools/bin/sdkmanager --sdk_root=${ANDROID_SDK_ROOT} "platform-tools" "platforms;android-${SDK_API_LEVEL}" "build-tools;${SDK_BUILD_TOOLS}"

Using Android Studio

Android Studio offers a convenient UI:

• to install all the dependencies;
• to manage android virtual devices;
• to make easy use of adb logs.

Building Libs and Tests for Android

Before running a build you might want to set the Android SDK and NDK environment variables:

export ANDROID_SDK_ROOT=<PATH-TO-ANDROID-SDK>
export ANDROID_NDK_ROOT=<PATH-TO-ANDROID-NDK>  

Now we're ready to build everything for Android:

./build.sh mono+libs -os Android -arch x64

and even run tests one by one for each library:

./build.sh libs.tests -os Android -arch x64 -test

Make sure an emulator is booted (see AVD Manager) or a device is plugged in and unlocked. AVD Manager tool recommends to install x86 images by default so if you follow that recommendation make sure -arch x86 was used for the build script.

Running individual test suites

The following shows how to run tests for a specific library

./dotnet.sh build /t:Test src/libraries/System.Numerics.Vectors/tests /p:TargetOS=Android /p:TargetArchitecture=x64

Running the functional tests

There are functional tests which aim to test some specific features/configurations/modes on a target mobile platform.

A functional test can be run the same way as any library test suite, e.g.:

./dotnet.sh build /t:Test -c Release /p:TargetOS=Android /p:TargetArchitecture=x64 src/tests/FunctionalTests/Android/Device_Emulator/PInvoke/Android.Device_Emulator.PInvoke.Test.csproj

Currently functional tests are expected to return 42 as a success code so please be careful when adding a new one.

Testing various configurations

It's possible to test various configurations by setting a combination of additional MSBuild properties such as RunAOTCompilation,MonoForceInterpreter, and some more.

1. AOT

To build for AOT only mode, add /p:RunAOTCompilation=true /p:MonoForceInterpreter=false to a build command.

2. AOT-LLVM

To build for AOT-LLVM mode, add /p:RunAOTCompilation=true /p:MonoForceInterpreter=false /p:MonoEnableLLVM=true to a build command.

3. Interpreter

To build for Interpreter mode, add /p:RunAOTCompilation=false /p:MonoForceInterpreter=true to a build command.

Test App Design

Android app is basically a Java Instrumentation and a simple Activity that inits the Mono Runtime via JNI. This Mono Runtime starts a simple xunit test runner called XHarness.TestRunner (see https://github.com/dotnet/xharness) which runs tests for all *.Tests.dll libs in the bundle. There is also XHarness.CLI tool with ADB embedded to deploy *.apk to a target (device or emulator) and obtain logs once tests are completed.

Obtaining the logs

XHarness for Android doesn't talk much and only saves test results to a file. However, you can also subscribe to live logs via the following command:

adb logcat -s "DOTNET"

Or simply open logcat window in Android Studio or Visual Studio.

AVD Manager

If Android Studio is installed, AVD Manager can be used from the IDE to create and start Android virtual devices. Otherwise, the Android SDK provides the avdmanager command line tool.

Example of installing, creating, and launching emulators from the command line (where SDK_API_LEVEL matches the installed Android SDK and EMULATOR_NAME_X86/EMULATOR_NAME_X64 are names of your choice):

# Install x86 image
${ANDROID_SDK_ROOT}/cmdline-tools/tools/bin/sdkmanager "system-images;android-${SDK_API_LEVEL};default;x86"

# Create x86 image
${ANDROID_SDK_ROOT}/cmdline-tools/tools/bin/avdmanager create avd --name ${EMULATOR_NAME_X86} --package "system-images;android-${SDK_API_LEVEL};default;x86"

# Launch emulator with x86 image
${ANDROID_SDK_ROOT}/emulator/emulator -avd ${EMULATOR_NAME_X86} &

# Install x64 image
${ANDROID_SDK_ROOT}/cmdline-tools/tools/bin/sdkmanager "system-images;android-${SDK_API_LEVEL};default;x86_64"

# Create x64 image
${ANDROID_SDK_ROOT}/cmdline-tools/tools/bin/avdmanager create avd --name ${EMULATOR_NAME_X64} --package "system-images;android-${SDK_API_LEVEL};default;x86_64"

# Launch emulator with x64 image
${ANDROID_SDK_ROOT}/emulator/emulator -avd ${EMULATOR_NAME_X64} &

The emulator can be launched with a variety of options. Run emulator -help to see the full list.

Existing Limitations

• -os Android is not supported for Windows yet (WSL can be used instead)
• XHarness.CLI is not able to boot emulators yet (so you need to boot via AVD Manager or IDE)
• AOT and Interpreter modes are not supported yet

Debugging the native runtime code using Android Studio

See Debugging Android