Android-NDK-with-Google-Test

How to use GoogleTest on Android Studio?

Requirements:

The latest version of NDK has the gtest included. (my ndk : 15.2.4203891)

I did not find a clear guide how to do it, But I followed this document and this questions.

If you are opening a new project, do not forget to check the 'include c++'.

Step1:

Create jni folder or use app/src/main/cpp folder.

Create 3 file:

foo.cpp:

int foo(int x, int y) { return x + y; }

foo.h:

extern int foo(int x, int y);

foo_unittest.cc:

#include <gtest/gtest.h>
#include "foo.h"

TEST(FooTest,ZeroZero) {
   EXPECT_EQ(0, foo(0, 0));
}
TEST(FooTest,OneOne) {
   EXPECT_EQ(2, foo(1, 1));
}

Step 2:

Add to CMakeLists.txt

cmake_minimum_required(VERSION 3.4.1)

add_library(foo SHARED src/main/jni/foo.cpp)

set(GOOGLETEST_ROOT ${ANDROID_NDK}/sources/third_party/googletest/googletest)
add_library(gtest STATIC ${GOOGLETEST_ROOT}/src/gtest_main.cc ${GOOGLETEST_ROOT}/src/gtest-all.cc)
target_include_directories(gtest PRIVATE ${GOOGLETEST_ROOT})
target_include_directories(gtest PUBLIC ${GOOGLETEST_ROOT}/include)

add_executable(foo_unittest src/main/jni/foo_unittest.cc)
target_link_libraries(foo_unittest gtest foo)

Add to build.gradle(app)

android {
    compileSdkVersion 26
    buildToolsVersion "26.0.1"
    defaultConfig {
       applicationId "com.example.utest"
        minSdkVersion 21 #lower from this can throw error: "error: only position independent executables (PIE) are supported. Aborted"
        targetSdkVersion 26
       versionCode 1
        versionName "1.0"
        ndk { abiFilters 'x86'}  #make sure that the ABI matches the target you use
        externalNativeBuild {
            cmake {
                targets "foo_unittest"  #important. this line add the test file
            }
       }
    }
   externalNativeBuild {
        cmake {
           path "CMakeLists.txt"
        }
   }
}

Step 3:

Sync the project,  run "Make Project".

If your build succeeds, will build both 'libfoo.so' and 'foo_unittest' under:

app/build/intermediates/cmake/debug/obj/x86/libfoo.so

app/.externalNativeBuild/cmake/debug/x86/foo_unittest

Step 4:

Open device or emulator and from the terminal (you can open the terminal from Android Studio, located at the bottom) write:

adb push app/build/intermediates/cmake/debug/obj/x86/libfoo.so /data/local/tmp/
adb push app/.externalNativeBuild/cmake/debug/x86/foo_unittest /data/local/tmp/
adb shell chmod 775 /data/local/tmp/foo_unittest
adb shell "LD_LIBRARY_PATH=/data/local/tmp /data/local/tmp/foo_unittest"