JUnit

1. Declare this is a Test method:

@Test 
public void method()

2. This method is executed before each Test:

Note: used to prepare the test environment (i.e. Read input files..)

@Before

public void method()

3. This method is executed after each Test:

Note: To cleanup environment (i.e. Delete temporary file, data..)

@After

public void method()

4.This method is executed ONLY once before start of All tests.

Note: To perform time intensive activities (i.e. DB connections..) 

@BeforeClass

public static void method()

5. This method is executed ONLY once after all tests.

Note: i.e. To disconnect DB

@AfterClass

public static void method()

6. To ignore one test method:

Note: Do not execute this method

@Ignore

some_method()

7, Fail the test if the method takes longer than n milliseconds:

Note: Fails the test if it takes > 100 milliseconds

@Test(timeout=100)

some_method()

8. Fail the test if method NOT throwing the named exception;

Note; Test has to throw out the specified exception.

@Test(expected=Some_Exception.class)

some_method()

9. Hamcrest
assertThat( actual, is(expected value));

Hamcrest comes with a library of useful matchers. Here are some of the most important ones.

• Core
• anything - always matches, useful if you don't care what the object under test is
• describedAs - decorator to adding custom failure description
• is - decorator to improve readability - see "Sugar", below
• Logical
• allOf - matches if all matchers match, short circuits (like Java &&)
• anyOf - matches if any matchers match, short circuits (like Java ||)
• not - matches if the wrapped matcher doesn't match and vice versa
• Object
• equalTo - test object equality using Object.equals
• hasToString - test Object.toString
• instanceOf, isCompatibleType - test type
• notNullValue, nullValue - test for null
• sameInstance - test object identity
• Beans
• hasProperty - test JavaBeans properties
• Collections
• array - test an array's elements against an array of matchers
• 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
• Number
• closeTo - test floating point values are close to a given value
• greaterThan, greaterThanOrEqualTo, lessThan, lessThanOrEqualTo - test ordering
• Text
• equalToIgnoringCase - test string equality ignoring case
• equalToIgnoringWhiteSpace - test string equality ignoring differences in runs of whitespace
• containsString, endsWith, startsWith - test string matching