Using Hamcrest to Assert in SwitchYard

Hamcrest is a framework for writing matcher objects. It allows you to define match rules declaratively. Use Hamcrest’s assertThat construct and the standard set of matchers, both of which you can statically import:

import static org.hamcrest. MatcherAssert .assertThat;
​import static org.hamcrest. Matchers .*;

Hamcrest comes with a library of useful matchers, such as:

• Core
  • anything: Always matches, useful if you do not want to know what the object under test is
  • describedAs: Decorator for adding custom failure description
  • is: Decorator to improve readability
• Logical
  • allOf: Matches if all matchers match, short circuits (like && in Java)
  • anyOf: Matches if any matchers match, short circuits (like || in Java)
  • not: Matches if the wrapped matcher does not 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