org.hamcrest.beans

Class HasPropertyWithValue<T>

java.lang.Object

org.hamcrest.BaseMatcher<T>

org.hamcrest.TypeSafeDiagnosingMatcher<T>

org.hamcrest.beans.HasPropertyWithValue<T>

All Implemented Interfaces:

Matcher<T>, SelfDescribing

public class HasPropertyWithValue<T>
extends TypeSafeDiagnosingMatcher<T>

Matcher that asserts that a JavaBean property on an argument passed to the mock object meets the provided matcher. This is useful for when objects are created within code under test and passed to a mock object, and you wish to assert that the created object has certain properties.

Example Usage

Consider the situation where we have a class representing a person, which follows the basic JavaBean convention of having get() and possibly set() methods for it's properties:

 public class Person {
   private String name;
   public Person(String person) {
     this.person = person;
   }
   public String getName() {
     return name;
   }
 }

And that these person objects are generated within a piece of code under test (a class named PersonGenerator). This object is sent to one of our mock objects which overrides the PersonGenerationListener interface:

 public interface PersonGenerationListener {
   public void personGenerated(Person person);
 }

In order to check that the code under test generates a person with name "Iain" we would do the following:

 Mock personGenListenerMock = mock(PersonGenerationListener.class);
 personGenListenerMock.expects(once()).method("personGenerated").with(and(isA(Person.class), hasProperty("Name", eq("Iain")));
 PersonGenerationListener listener = (PersonGenerationListener)personGenListenerMock.proxy();

If an exception is thrown by the getter method for a property, the property does not exist, is not readable, or a reflection related exception is thrown when trying to invoke it then this is treated as an evaluation failure and the matches method will return false.

This matcher class will also work with JavaBean objects that have explicit bean descriptions via an associated BeanInfo description class. See the JavaBeans specification for more information: http://java.sun.com/products/javabeans/docs/index.html

Constructor Summary

Constructors

Constructor and Description
HasPropertyWithValue(java.lang.String propertyName, Matcher<?> valueMatcher)
HasPropertyWithValue(java.lang.String propertyName, Matcher<?> valueMatcher, java.lang.String messageFormat)

Method Summary

Modifier and Type	Method and Description
void	describeTo(Description description) Generates a description of the object.
static <T> Matcher<T>	hasProperty(java.lang.String propertyName, Matcher<?> valueMatcher) Creates a matcher that matches when the examined object has a JavaBean property with the specified name whose value satisfies the specified matcher.
static <T> Matcher<T>	hasPropertyAtPath(java.lang.String path, Matcher<T> valueMatcher) Creates a matcher that matches when the examined object is a graph of JavaBean objects that can be navigated along the declared dot-separated path and the final element of that path is a JavaBean property whose value satisfies the specified matcher.
boolean	matchesSafely(T bean, Description mismatch) Subclasses should implement this.

Methods inherited from class org.hamcrest.TypeSafeDiagnosingMatcher

describeMismatch, matches

Methods inherited from class org.hamcrest.BaseMatcher

_dont_implement_Matcher___instead_extend_BaseMatcher_, isNotNull, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

HasPropertyWithValue

public HasPropertyWithValue(java.lang.String propertyName,
                            Matcher<?> valueMatcher)

HasPropertyWithValue

public HasPropertyWithValue(java.lang.String propertyName,
                            Matcher<?> valueMatcher,
                            java.lang.String messageFormat)

Method Detail

matchesSafely

public boolean matchesSafely(T bean,
                             Description mismatch)

Description copied from class: TypeSafeDiagnosingMatcher

Subclasses should implement this. The item will already have been checked for the specific type and will never be null.

Specified by:

matchesSafely in class TypeSafeDiagnosingMatcher<T>

describeTo

public void describeTo(Description description)

Description copied from interface: SelfDescribing

Generates a description of the object. The description may be part of a a description of a larger object of which this is just a component, so it should be worded appropriately.

Parameters:

description - The description to be built or appended to.

hasProperty

public static <T> Matcher<T> hasProperty(java.lang.String propertyName,
                                         Matcher<?> valueMatcher)

Creates a matcher that matches when the examined object has a JavaBean property with the specified name whose value satisfies the specified matcher. For example:

assertThat(myBean, hasProperty("foo", equalTo("bar"))

Parameters:

propertyName - the name of the JavaBean property that examined beans should possess

valueMatcher - a matcher for the value of the specified property of the examined bean

hasPropertyAtPath

public static <T> Matcher<T> hasPropertyAtPath(java.lang.String path,
                                               Matcher<T> valueMatcher)

Creates a matcher that matches when the examined object is a graph of JavaBean objects that can be navigated along the declared dot-separated path and the final element of that path is a JavaBean property whose value satisfies the specified matcher. For example:

assertThat(myBean, hasProperty("foo.bar.baz", equalTo("a property value"))

Parameters:

path - the dot-separated path from the examined object to the JavaBean property

valueMatcher - a matcher for the value of the specified property of the examined bean