Hamcrest ?

- Hamcrest is a set of matchers framework for writing matcher objects
- Hamcrest is integrated into JUnit
- Instead of using JUnit’s assertEquals methods, we use Hamcrest’s assert



The following list contains the most important Hamcrest matchers.

• is - decorator to improve readability
  
• 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 versa
  
• equalTo - test object equality using Object.equals
  
• 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 - test ordering
  
• equalToIgnoringCase - test string equality ignoring case
  
• equalToIgnoringWhiteSpace - test string equality ignoring differences in runs of whitespace
  
• containsString, endsWith, startsWith - test string matching
  

 

 The following assertions are all equivalent: 

assertThat(theBiscuit, equalTo(myBiscuit));
assertThat(theBiscuit, is(equalTo(myBiscuit)));
assertThat(theBiscuit, is(myBiscuit));