Well, you can now …

Version 2.2.1

  • …use single value enums as key in a Map. (Issue 166)

Version 2.2

  • …be more specific about which fields may be null, using withNonnullFields. (Issue 134)
  • …have an uninitialized static array in your class without getting a NullPointerException. (Issue 165)
  • …see more helpful error messages.

Version 2.1.8

  • …test classes that implement an abstract class that calls an abstract method in its equals or hashCode methods, when EqualsVerifier is called with usingGetClass. (Issue 161)

Version 2.1.7

  • …use single value enums again. (Issue 157; thanks Stephan!)

Version 2.1.6

October 1, 2016

  • …no longer get NullPointerExceptions in situations where annotations which are available at compile time, are not available at runtime. (Issue 153 and Issue 154)

Version 2.1.5

August 6, 2016

  • …avoid adding prefab values for java.util.Vector and java.util.Stack. (Issue 151)

Version 2.1.4

July 25, 2016

  • …use Guava’s Range with full reflection support. (Issue 150; thanks Stephan!)

Version 2.1.3

July 17, 2016

  • …use EqualsVerifier when older versions of Google Guava are on the classpath. (Issue 149)

Version 2.1.2

June 20, 2016

  • …use EqualsVerifier concurrently. (Issue 148; thanks Borys!)

Version 2.1.1

June 14, 2016

  • …not get VerifyErrors in certain situations, such as when running unit tests with coverage in IntelliJ. (Issue 147)
  • …have the (current) latest version of ByteBuddy. (Issue 145; thanks Vincent!)

Version 2.1

May 22, 2016

  • …suppress Warning.STRICT_HASHCODE to let EqualsVerifier allow hashCode methods that don’t use all the fields that are also used in equals, or even constant hashCodes. (Issue 142)
  • …assert, within a class’s equals or hashCode method, on the length of its array field. (Issue 143)
  • …get an equalsverifier.jar file without Objenesis’s meta-data in the META-INF folder. (Issue 144)
  • …no longer get a ReflectionException when EqualsVerifier is unable to read annotations on fields in certain situations. (Issue 14, Comment 21)

Version 2.0.2

April 3, 2016

  • …test classes that implement an abstract class that calls an abstract method in its equals or hashCode methods. (Issue 138)
  • …use EqualsVerifier on a JVM that doesn’t have javax.naming.Reference available. (Issue 114)

Version 2.0.1

March 13, 2016

  • …test classes that have a static final reference to a recursive data structure, without adding prefab values.
  • …test classes that have a generic parameter that extends Comparable. (Issue 136)
  • …no longer have show up on your classpath. (Issue 135; thanks Stephan!)

Version 2.0

March 6, 2016

If you’re upgrading from EqualsVerifier 1, please see the migration guide.

  • …no longer use EqualsVerifier with Java 6.
  • …no longer use EqualsVerifier.forExamples. Use #forClass or #forRelaxedEqualExamples instead.
  • …no longer use #debug() (which didn’t do anything, anyway).
  • …expect “all fields should be used” to be the default behaviour. (Issue 65)
    • Suppress Warning.ALL_FIELDS_SHOULD_BE_USED to revert back to the old behaviour.
    • #forRelaxedEqualExamples implicitly suppresses Warning.ALL_FIELDS_SHOULD_BE_USED.
    • Suppressing Warning.IDENTICAL_COPY_FOR_VERSIONED_ENTITY implicitly suppresses Warning.ALL_FIELDS_SHOULD_BE_USED.
    • #allFieldsShouldBeUsedExcept() is now removed.
    • Use #withIgnoredFields() to disregard specific fields, while expecting all remaining fields to be used in equals.
    • Use #withOnlyTheseFields() to expect that the given fields are used, and that the remaining fields are not used. (Issue 128)
  • …expect EqualsVerifier to fail when equals isn’t overridden (i.e., inherited directly from Object). (Issue 66)
    • Suppress Warning.INHERITED_DIRECTLY_FROM_OBJECT to revert back to the old behaviour.
  • …refer to the generic contents of containers, such as List and Optional, in the implementation of equals and hashCode. (Issue 84)
  • …get more useful information from the stack trace if EqualsVerifier fails.
  • …have better compatibility with Java 8. (Issue 115)
  • …know that EqualsVerifier’s code quality has been improved, as a result of adding CheckStyle and FindBugs, and doing mutation tests with PIT.

Version 1.7.8

February 26, 2016

  • …use EqualsVerifier and Java 8’s -parameters compiler option in the same project.

Version 1.7.7

January 18, 2016

  • …use EqualsVerifier together with Cobertura. (Issue 132)

Version 1.7.6

December 21, 2015

  • …have a field whose type is an interface that defines equals. (Issue 130)
  • …get 100% mutation coverage with PIT on your equals and hashCode methods. (Issue 131)

Version 1.7.5

August 29, 2015

  • …get symmetry warnings if the symmetry violation only occurs in the subclass of a versioned entity. (Issue 123, Comment 10)
  • …get a warning when the id check on a versioned entity is implemented incorrectly. (Issue 123, Comment 17)
  • …omit suppression of Warning.NONFINAL_FIELDS on classes marked @Embeddable and @MappedSuperclass. (Issue 124 and Issue 123, Comment 15)
  • …use singleton enums without null-checking. (Issue 125)

Version 1.7.4

August 17, 2015

  • …avoid adding prefab values for
  • …avoid exceptions thrown from SBT. (Issue 119)
  • …get better reporting on subclasses of versioned entities. (Issue 123)

Version 1.7.3

July 18, 2015

  • …use a protected or default-visibility cachedHashCode field with #withCachedHashCode(). (Issue 110)
  • …have a static final field with null value without getting a NullPointerException. (Issue 116)
  • …know that several things have been improved behind-the-scenes :).

Version 1.7.2

March 28, 2015

  • …use Eclipse’s JDT null annotations, including the Java 8 style type annotations.
  • …have a static field with an empty array in the class under test, without getting an ArrayIndexOutOfBoundsException. (Issue 106)
  • …revel in the fact that all dependencies have been updated (Issue 107) and that several potential bugs have been solved using PIT.

Version 1.7.1

March 11, 2015

  • …use EqualsVerifier again, without suppressing 1.7’s REFERENCE_EQUALITY warning, on classes containing:
    • certain interfaces, and classes which don’t redefine equals. (Issue 104, Comment 6)
    • a static final lambda field. (Issue 105)

Version 1.7

March 4, 2015

  • …verify classes that cached their hashCode, using #withCachedHashCode(). (Issue 60; thanks Niall!)
  • …avoid adding prefab values for several Java Collections interface classes, including SortedSet and TreeSet. (Issue 103)
  • …get an error message when you accidentally use == instead of equals on an object field inside your equals method, and suppress this using Warning.REFERENCE_EQUALITY. (Issue 104)

Version 1.6

January 17, 2015

  • …set default @Nonnull annotations on your classes (Issue 50)
    • using Findbugs’s @DefaultAnnotation or @DefaultAnnotationForFields.
    • using a JSR 305 annotation (see this StackOverflow question).
    • you can put them on the class, or on the package.
    • you can override the default by placing @Nullable or @CheckForNull on a field.
  • …verify stateless classes. (Issue 46)
  • …verify classes with stateless fields. (Issue 100 and Issue 101)
  • …verify the consistency of hashCode in a stateless object. (Issue 97)
  • …verify classes where equality is fully defined in a superclass, for example using Apache Commons’s EqualsBuilder.reflectionEquals. (Issue 102)

Version 1.5.1

December 5, 2014

  • …use EqualsVerifier when incompatible versions of ASM and/or CGLib are on the classpath. EqualsVerifier is now shipped as an “uber jar” which contains all its dependencies inside. (Issue 96)
  • …use EqualsVerifier with older versions of Google Guava on the classpath. (Issue 98)
  • …build EqualsVerifier itself using Maven instead of Ant+Ivy.

Version 1.5

August 20, 2014

  • …use EqualsVerifer in Java 8! Classes containing Java 8 language features are now supported, and prefab values for new Java 8 API classes have been added. (Issue 92)
  • …stop adding prefab values for Joda-Time and Google Guava, because EqualsVerifier now provides them for you. (Issue 83)
  • …have correct error messages when your class contains multi-dimensional arrays. (Issue 90 and Issue 94)
  • …use Arrays.equals instead of Arrays.deepEquals on Object[] fields. (Issue 94)
  • …use the super class’s equals method when specifying #allFieldsShouldBeUsed() (Issue 95; thanks Dean!)
  • …get better error messages when equals or hashCode are themselves abstract.
  • …find and understand EqualsVerifier’s unit tests more easily, as they have been heavily refactored.

Version 1.4.1

March 18, 2014

  • …pass enums through EqualsVerifier without error. (Issue 87)
  • …get more thorough reflexivity and symmetry tests, which will catch small mistakes such as the one in Issue 88.

Version 1.4

December 27, 2013

  • …have confidence that EqualsVerifier covers 100% of your equals and hashCode methods. (FAQ)
  • …specifically ignore certain fields using #allFieldsShouldBeUsedExcept(). (Issue 82)
  • …test classes that have an array field, but that don’t declare an equals method.
  • …get clearer error messages around abstract delegation. This clarifies especially classes that contain Joda-Time LocalDate fields.
  • …stop worrying about adding prefab values for BitSet. (Issue 86)

Version 1.3.1

June 9, 2013

  • …read error messages on the new EqualsVerifier website at, which matches EqualsVerifier’s fully qualified name: nl.jqno.equalsverifier.EqualsVerifier.
  • …disregard .debug(), as it is deprecated. Relevant exceptions are now included as a cause in the stack trace.
  • …test “versioned entity” classes where a zero id field indicates that the object is new, by suppressing Warning.IDENTICAL_COPY_FOR_VERSIONED_ENTITY. (Issue 80)
  • …get more accurate transitivity errors. (Issue 78)
  • …stop worrying about exceptions thrown in toString. (Issue 79)
  • …stop worrying about adding prefab values for UUID, to avoid that pesky recursion warning. (Issue 81)

Version 1.3

June 9, 2013

Please don’t use version 1.3; it’s a broken release. Use 1.3.1 instead.

Version 1.2

March 26, 2013

  • …get a transitivity error message for classes that use or in their equals method. (Issue 75; blog post about the problem and the solution)
  • …expect more robustness from EqualsVerifier when the toString method of the class under tests throws exceptions.
  • …use single value enums (and hence, singletons) in your classes, even if they don’t count for equals and hashCode. (Issue 74)
  • …use forRelaxedEqualExamples with classes containing null fields. (Issue 73)
  • …run EqualsVerifier’s test suite with less chance of false negatives. (Issue 77)
  • …build EqualsVerifier using Ant 1.9. (Issue 76)

Version 1.1.4

January 14, 2013

  • … fork EqualsVerifier on GitHub! EqualsVerifier has moved its code to GitHub. The project frontpage will remain at Google Code.
  • … use EqualsVerifier on a class whose superclasses have no declarations for equals and hashCode. (Issue 63)
  • … get an error when using #allFieldsShouldBeUsed() on a class that has fields but no declarations for equals and hashCode (and hence doesn’t use these fields). (Issue 67)
  • … get a more informative error message on Abstract Delegation errors: EqualsVerifier now also mentions the name of the abstract method that was called.

Version 1.1.3

April 21, 2012

  • … add static fields to your classes that are tested with #allFieldsShouldBeUsed(). EqualsVerifier will no longer complain if these static fields aren’t used in your equals and hashCode methods. (Issue 57)
  • … get a complaint from EqualsVerifier when your equals method works incorrectly if a field in the class under test is null. (Issue 59)

Version 1.1.2

March 1, 2012

  • … stop worrying about EqualsVerifier recursively changing the value of non-final static fields, causing other tests to fail. (Issue 55, Comment 8)

Version 1.1.1

February 21, 2012

  • … suppress Warning.IDENTICAL_COPY if you want to use reference equality in an overridden equals method. (Issue 56)

Version 1.1

February 11, 2012

  • … get a warning if you forgot to include a field in your equals or hashCode method, by calling the #allFieldsShouldBeUsed() method on EqualsVerifier. (Issue 53)
  • … get an error message if you include a reference-equality check (this == obj), followed by an incorrect instanceof check in your equals method. EqualsVerifier will now notice if you do an instanceof check for a class other than the one that you are testing. (Issue 55, Comment 2)
  • … stop worrying about EqualsVerifier changing the value of non-final static fields, causing other tests to fail. (Issue 52 and Issue 55)
  • … stop worrying about adding prefab values for File, List, Set, Map and Collection to avoid unjustified warning. (Issue 49 and Issue 51)

Version 1.0.2

August 14, 2011

  • … find EqualsVerifier in Maven Central! (Issue 36)
  • … get an error message when you forget to include an instanceof check or a getClass() check in your equals method. (Issue 47)
  • … use EqualsVerifier on a class whose superclass has abstract declarations for equals and hashCode. (Issue 48)

Version 1.0.1

April 17, 2011

  • … use EqualsVerifier on dynamically generated classes by disabling annotation processing. (Issue 41)
  • … use EqualsVerifier on classes that are a subclass of one of the classes from rt.jar, which are loaded by the system classloader. (Issue 43)
  • … use EqualsVerifier on classes with float or double fields but no equals method. (Issue 44)
  • … stop worrying about adding prefab values for Throwable and Exception, to avoid that pesky recursion warning. (Issue 45)

Version 1.0

February 23, 2011

  • … use the following annotations on your classes and fields: EqualsVerifier will know what to do!
    • @Immutable: EqualsVerifier will not complain about non-final fields if your class is @Immutable. (It doesn’t matter in which package the annotation is defined; javax.annotations.concurrent.Immutable, net.jcip.annotations.Immutable or your own implementation will all work fine.)
    • @Nonnull, @NonNull and @NotNull: EqualsVerifier will not check for potential NullPointerExceptions for any field marked with any of these annotations. (Again: the source package doesn’t matter.) This is similar to calling suppress(Warning.NULL_FIELDS), but on a per-field basis, instead of all-or-nothing. (Issue 28)
    • @Entity: EqualsVerifier will not complain about non-final fields if your class is a JPA Entity. Note that this only works for javax.persistence.Entity, not for Entity annotations from other packages. (Issue 37)
    • @Transient: Fields marked with this annotation (again, only from javax.persistence.Transient), will be treated the same as fields marked with Java’s transient modifier; i.e., EqualsVerifier will complain if they are used in the equals contract.
  • … see which field throws a potential NullPointerException, instead of having to guess which one it was. (Issue 39)
  • … be sure that EqualsVerifier doesn’t detect recursive data structures where there are none. (Issue 34)
  • … stop worrying about adding prefab values for BigDecimal and BigInteger, to avoid that pesky recursion warning. (Issue 34)

Version 0.7

November 15, 2010

  • … test equals methods that use a call to getClass(), instead of an instanceof check, to determine the type of the object passed in, by calling the #useGetClass() method on EqualsVerifier.
  • … get a warning when you use a transient field in your equals or hashCode method. Don’t worry; you can suppress this warning too.
  • … stop worrying about adding prefab values for certain Java API classes, like Date, GregorianCalendar, or Pattern, to avoid that pesky recursion warning.
  • … get a link to the Error messages page to get more help, when EqualsVerifier finds an error.
  • … enjoy many javadoc improvements (including the one in Issue 32).
  • Also, the back end is almost completely re-written.

Version 0.6.5

August 5, 2010

  • … use EqualsVerifier on classes with fields of a wide variety of Java API types, without getting ‘Recursive datastructure’ errors all the time. (Issue 30)
  • … get a more helpful error message when equals, hashCode or toString throws something other than a NullPointerException when one of the fields in null. (Issue 31)

Version 0.6.4

June 13, 2010

  • … get an appropriate error message when Arrays.hashCode() or Arrays.deepHashCode() should have been used, instead of a message that a certain field is used in equals but not in hashCode or the other way around. (Issue 27)
  • … get less frequent non-nullity errors on toString.

Version 0.6.3

May 18, 2010

  • … test the equals/hashCode contract for classes that don’t override equals or hashCode. (Issue 23)
  • … use EqualsVerifier in conjuction with the EclEmma code coverage tool. (Issue 22)
  • … test classes that contain (indirect) references to non-static inner classes, without getting messages about recursive data structures. (Issue 21)

Version 0.6.2

February 11, 2010

  • … use #withPrefabValues() for recursive data structure fields in superclasses again. (Issue 20)

Version 0.6.1

February 6, 2010

  • … use #withPrefabValues() for fields which delegate to abstract methods again. (Issue 14)
  • … access the #verify() method more quickly using autocompletion in IDEs. (The method #verbose() has been renamed to #debug().)

Version 0.6

January 30, 2010

  • … use a more consistent API. #with(Feature) is now #suppress(Warning), which feels more Java-y. Former features that were not warnings, are now proper methods on EqualsVerifier: #verbose() and #withRedefinedSuperclass().
  • … get better error messages:
    • many messages now span multiple lines for improved readability;
    • hashCodes are printed (where relevant);
    • unexpected exceptions are no longer eaten by EqualsVerifier, so they can be read without calling #verbose();
    • calls to abstract methods from within equals and hashCode, which cannot be resolved, are now detected and properly reported. (Issue 14)
  • … verify classes that contain fields whose equals methods might throw NullPointerExceptions. (Issue 19)
  • … be sure that EqualsVerifier doesn’t detect recursive data structures where there are none. (Issue 18)
  • … use fields of type Class in your classes. (Issue 17)

Version 0.5

September 1, 2009

  • … test classes that contain fields of interface or abstract class types (such as Lists, and other Collection types). (Issue 12)
  • … step through the source code in Eclipse after adding the EqualsVerifier jar to your project. (Issue 11)

Version 0.4

August 29, 2009

  • … verify equality rules that are more relaxed than simple field-by-field comparison. (Issue 9)

Version 0.3

August 1, 2009

  • … use EqualsVerifier without having to call #withPrefabValues(...) all the time. (Issue 7)

Version 0.2

July 3, 2009

  • … use the fields are never null feature on classes instantiated with #forClass(Class). (Issue 1)
  • … check if Arrays.deepEquals was used for multidimensional and Object arrays. (Issue 3)
  • … access optional features through a clean enum instead of through lots of different method calls. (Issue 4)
  • … use EqualsVerifier in unit test frameworks other than JUnit 4 (Issue 5)
  • … have stacktraces be printed to System.err. (Issue 6)

Version 0.1

June 1, 2009

  • … use EqualsVerifier!