Hamcrest Test Framework

 Hamcrest란?

test framework을 이용하여 단위 테스트 진행 시 assert를 유연하게 하기 위해 matcher를 이용하여 좀 더 쉽고 확장성 있는 assert를 하기 위해 만들어진 framework이다. 

Hamcrest는 처음부터 test framework과 통합되도록 설계되어 JUnit, TestNG와 함께 사용할 수 있다.

maven dependency

<dependency>
    <groupId>org.hamcrest</groupId>
    <artifactId>hamcrest-library</artifactId>
    <version>2.2</version>
    <scope>test</scope>
</dependency>

Hamcrest code

assertThat(actual, is(equalTo(expedted);
assertThat(result, instanceof String);
assertThat(result, is(hasItem(anyOf(equalTo("x", equalTo("y"), equalTo("z"))))));

Hamcrest Matcher 

allOf - matches if all matchers match (short circuits)

anyOf - matches if any matchers match (short circuits)

not - matches if the wrapped matcher doesn’t match and vice

equalTo - test object equality using the equals method

is - decorator for equalTo to improve readability

hasToString - test Object.toString

instanceOf, isCompatibleType - test type

notNullValue, nullValue - test for null

sameInstance - test object identity

hasEntry, hasKey, hasValue - test a map contains an entry, key or value

hasItem, hasItems - test a collection contains elements

hasItemInArray - test an array contains an element

closeTo - test floating point values are close to a given value

greaterThan, greaterThanOrEqualTo, lessThan, lessThanOrEqualTo

equalToIgnoringCase - test string equality ignoring case

equalToIgnoringWhiteSpace - test string equality ignoring differences in runs of whitespace

containsString, endsWith, startsWith - test string matching

Junit MultiThread Test code

import org.junit.Test;

import junit.framework.TestCase;
import net.sourceforge.groboutils.junit.v1.MultiThreadedTestRunner;
import net.sourceforge.groboutils.junit.v1.TestRunnable;

public class TestThread extends TestCase{
 
 private static int THREAD_SIZE = 20;
 
 /*
  * Test class should have exactly one public zero-argument constructor이므로
  * TestCase 클래스를 extends 하고 GroboUtils의 클래스인 TestRunnable을 상속받은 클래스를 이너클래스로 사용하였다.
  */
 
 public class MultiThreadTest extends TestRunnable {
  
  private int i = 0;
  
  
  public MultiThreadTest(int i){
   this.i = i;
  }
  
  @Override
  public void runTest() throws Throwable {
   Thread.sleep(1000);
   
   System.out.println(Thread.currentThread().getName() + " : [" + i + "]");
  }
 }
 
 @Test
 public void test() throws Throwable{
  TestRunnable[] t = new TestRunnable[THREAD_SIZE];
  
  for(int index=0; index < THREAD_SIZE; index++){
   t[index]=new MultiThreadTest(index);
  }
  
  MultiThreadedTestRunner mttr = new MultiThreadedTestRunner(t);
  mttr.runTestRunnables();
  
  System.out.println("main end.........................");
 }
}