org.assertj.core.internal

Class DeepDifference

java.lang.Object

org.assertj.core.internal.DeepDifference

public class DeepDifference
extends Object

Tests two objects for differences by doing a 'deep' comparison. Based on the deep equals implementation of https://github.com/jdereg/java-util

Author:

John DeRegnaucourt ([email protected]), Pascal Schumacher

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DeepDifference.Difference

Constructor Summary

Constructors

Constructor and Description
DeepDifference()

Method Summary

Methods

Modifier and Type	Method and Description
static List<DeepDifference.Difference>	determineDifferences(Object a, Object b, Map<String,Comparator<?>> comparatorByPropertyOrField, Map<Class<?>,Comparator<?>> comparatorByType) Compare two objects for differences by doing a 'deep' comparison.

Methods inherited from class java.lang.Object

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

Constructor Detail

DeepDifference

public DeepDifference()

Method Detail

determineDifferences

public static List<DeepDifference.Difference> determineDifferences(Object a,
                                                   Object b,
                                                   Map<String,Comparator<?>> comparatorByPropertyOrField,
                                                   Map<Class<?>,Comparator<?>> comparatorByType)

Compare two objects for differences by doing a 'deep' comparison. This will traverse the Object graph and perform either a field-by-field comparison on each object (if not .equals() method has been overridden from Object), or it will call the customized .equals() method if it exists.

This method handles cycles correctly, for example A->B->C->A. Suppose a and a' are two separate instances of the A with the same values for all fields on A, B, and C. Then a.deepEquals(a') will return an empty list. It uses cycle detection storing visited objects in a Set to prevent endless loops.

Parameters:

a - Object one to compare

b - Object two to compare

Returns:

the list of differences found or an empty list if objects are equivalent. Equivalent means that all field values of both subgraphs are the same, either at the field level or via the respectively encountered overridden .equals() methods during traversal.