https://github.com/appium/appium/commit/show/68fc399f8561adf27dd780350aba4a25900207fb/f47ecbf#diff-f47ecbf9f94af03d121530d897bb9276

Android coverage requires the emulator or a rooted device. Build your app using the instrument target, for example $ ant instrument

Pass androidCoverage to your device capabilities and set it to your instrumentation class.

caps = { androidCoverage: 'com.example.pkg/com.example.pkg.instrumentation.MyInstrumentation' }

Appium will start your app like this: adb shell am instrument -e coverage true -w com.example.pkg/com.example.pkg.instrumentation.MyInstrumentation

After your test completes, it's time to end the coverage collection and pull the coverage.ec file from the device.

mobile :endCoverage, intent: 'com.example.pkg.END_EMMA', path: '/mnt/sdcard/coverage.ec'

--

AndroidManifest.xml defines the instrumentation and broadcast receiver.

<instrumentation
    android:name="com.example.pkg.instrumentation.MyInstrumentation"
    android:targetPackage="com.example.pkg" >
</instrumentation>

<!-- adb shell am broadcast -a com.example.pkg.END_EMMA -->
<receiver android:name="com.example.pkg.instrumentation.EndEmmaBroadcast" >
   <intent-filter>
       <action android:name="com.example.pkg.END_EMMA" />
   </intent-filter>
</receiver>

EndEmmaBroadcast.java is defined as:

package com.example.pkg.instrumentation;

import java.io.File;

import android.annotation.SuppressLint;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Process;
import android.util.Log;

// adb shell am broadcast -a com.example.pkg.END_EMMA
@SuppressLint("SdCardPath")
public class EndEmmaBroadcast extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        Log.d("AppiumEmma", "EndEmmaBroadcast broadcast received!");
        // reflection is used so emma doesn't cause problems for other build targets
        // that do not include emma.
        try {
            Class.forName("com.vladium.emma.rt.RT")
                    .getMethod("dumpCoverageData", File.class, boolean.class, boolean.class)
                    .invoke(null, new File("/mnt/sdcard/coverage.ec"), false, false);
        } catch (Exception e) {
            Log.d("AppiumEmma", e.toString());
        }

        // once coverage is dumped, the processes is ended.
        Process.killProcess(Process.myPid());
    }
}

MyInstrumentation.java is defined as:

package com.example.pkg.instrumentation;

import android.app.Instrumentation;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.support.v4.content.LocalBroadcastManager;

public class MyInstrumentation extends Instrumentation {
    private Intent intent;

    @Override
    public void onCreate(Bundle arguments) {
        intent = getTargetContext().getPackageManager()
                .getLaunchIntentForPackage("com.example.pkg")
                .setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        start(); // creates new thread which invokes onStart
    }

    @Override
    public void onStart() {
        startActivitySync(intent);
        LocalBroadcastManager.getInstance(getTargetContext()).registerReceiver(
                new EndEmmaBroadcast(), new IntentFilter("com.example.pkg.END_EMMA"));
    }
}

Reports

ant instrument generates a coverage.em file. The mobile :endCoverage will download the coverage.ec file for that particular run. Note that you can have any number of coverage.ec files. To merge them all together into a report, use this command:

java -cp /path/to/android-sdk-macosx/tools/lib/emma_device.jar emma report -r html -in coverage.em,coverage0.ec,coverage1.ec -sp /path/to/your-app/src