05. Introduction to JUnits

# Introduction to JUnits
We'll now go through a hands-on example that will get you some experience testing using JUnits.

To follow along, you can download the starter code that Sareeta uses from this GitHub repository.

Getting familiar with the starter code

Writing JUnits for the helper methods

Writing tests on the Helper class

Solution

Below is solution code for all of the tests, including getMergedList. We encourage you to try out as many of these as you like, and compare your code with the examples. (As always, it's possible your code looks a bit different and still accomplishes the end goal!)

```
package com.udacity.examples.Testing;

import static org.junit.Assert.assertArrayEquals;
import static org.junit.Assert.assertEquals;

import java.util.Arrays;
import java.util.List;

import org.junit.After;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;

public class HelperTest {

@Test
public void test() {
    assertEquals("test", "test1");
}

@Test
public void test1() {
    assertEquals("test", "test");
}

/**
 * Need to be void and public
 * @return
 * 
 * @Test
private String test2() {
    return "";
}
 */

@Test
public void validate_getCount() {
    List<String> empNames = Arrays.asList("sareeta", "", "john","");
    assertEquals(2, Helper.getCount(empNames));
}

@Test
public void validate_3lengthString() {
    List<String> empNames = Arrays.asList("sareeta", "", "Jeff","sam");
    assertEquals(2, Helper.getStringsOfLength3(empNames));
}

/*
 * Part 2
 * why not to use test in the name?
 * Because annotations s
 */

@Test
public void verify_list_is_squared(){
      List<Integer> yrsOfExperience = Arrays.asList(13,4,15,6,17,8,19,1,2,3);
      List<Integer> expected = Arrays.asList(169, 16, 225, 36, 289, 64, 361, 1, 4, 9);
      assertEquals(expected, Helper.getSquareList(yrsOfExperience));
}


/**
 * assertFail vs asserTrue
 */


@Before
public void init() {
     System.out.println("init executed");

}

@After
public void teardown() {
     System.out.println("teardown executed");
}

@Test
public void verify_merged_list(){
    List<String> empNames = Arrays.asList("sareeta", "", "john","");
      assertEquals("sareeta, john", Helper.getMergedList(empNames));
}

@Test
public void verify_getMax(){
      List<Integer> empLevel = Arrays.asList(3,3,3,5,7,2,2,5,7,5);
      assertEquals(7, Helper.getStats(empLevel).getMax());
}
/**
 * this should be public static
 */

@BeforeClass
public static void initClass() {
     System.out.println("init Class executed");

}


@AfterClass
public static void teardownclass() {
     System.out.println("teardown Class executed");
}


/**
 *assertArrayEquals
 *How should you debug this?
 */

@Test
public void verify_ArrayListTest(){
      int[] yrsOfExperience = {13,4,15,6,17,8,19,1,2,3};
      int[] expected = {13,4,15,6,17,8,19,1,2,3};
      assertArrayEquals(expected, yrsOfExperience);
}

/**
 * parameterized test next class
 */

}```