Android Instrumentation Testing

" Jai Saraswati Maa" 
Hi ... Dear All ..Today I am uploading a superb example of Android Instrumentation Test.
It will l test your code with your emulator or physical device.
In MainActivity i am inserting simple text in edit text and on button click i will display text inserted into TextView.
Its also known as Activity Test. 
I am using Android Studio 1.5.1
Minimun SDK API 19
Target SDK API 23
Please Like us & put your valuable suggestions in comment box.
Just Read Carefully ........ There is some configuration tips required.
**** Nothing added in manifest file or build gradle file so don't worry its very easy.
********* See when you run this test your application runs and disappear.
A.  Layout will be like ....

  
B.    xml code   activity_main.xml

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context="com.exam.ravi.junittestex1.MainActivity">

    <EditText        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:id="@+id/editText"

        android:layout_alignParentTop="true"

        android:layout_alignParentStart="true"

        android:layout_alignParentEnd="true" />

    <Button        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="Click Me"

        android:id="@+id/button"        android:layout_below="@+id/editText"

        android:layout_centerHorizontal="true"

        android:layout_marginTop="42dp"

        android:onClick="clickButton" />

    <TextView        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:textAppearance="?android:attr/textAppearanceLarge"

        android:text="Large Text"

        android:id="@+id/textView"

        android:layout_centerVertical="true"

        android:layout_centerHorizontal="true" />
</RelativeLayout>

C.  Java code  MainActivity.java is as 

package com.exam.ravi.junittestex1;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    @Override    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    public void clickButton(View view) {
        EditText editText =
                (EditText) findViewById(R.id.editText);

        String name = editText.getText().toString();
        String setData = String.format("Hello, %s!", name);

        TextView textView =
                (TextView) findViewById(R.id.textView);

        textView.setText(setData);
    }
}

*************  Now Test Procedure started .....

1.  Create a Java Class under androidTest Package to test your MainActivity

****** i had created MainActTest which is as 

package com.exam.ravi.junittestex1;

import android.test.ActivityInstrumentationTestCase2;
import android.test.TouchUtils;
import android.widget.Button;
import android.widget.TextView;

public class MainActTest extends ActivityInstrumentationTestCase2<MainActivity> {
    public MainActTest() {
        super(MainActivity.class);
    }

    public void testActivityExists() {
        MainActivity activity = getActivity();
        assertNotNull(activity);
    }
    public void testApply() {
        MainActivity activity = getActivity();
        getInstrumentation().waitForIdleSync();
        getInstrumentation().sendStringSync("Ravi");
        Button button =
                (Button) activity.findViewById(R.id.button);

        TouchUtils.clickView(this, button);
        TextView message = (TextView) activity.findViewById(R.id.textView);
        String actualText = message.getText().toString();
        assertEquals("Hello, Ravi!", actualText);

    }

} 

2.  How configure ......

step 1. Select Android Instrumentation Tests in Build Variant  as  

step 2. configure your AndroidTest Package using Edit Configuration with Run 

step 3 Run your Test 

3.1   Successful ..... when inserted and expected are same Text .... 

3.2   Failed ....  when inserted and expected are not same  Text ....