Assert (AssertJ fluent assertions 2.5.0 API)

Type Parameters:
S - the "self" type of this assertion class. Please read "Emulating 'self types' using Java Generics to simplify fluent API implementation" for more details.
A - the type of the "actual" value.

All Superinterfaces:

Descriptable<S>, ExtensionPoints<S,A>

All Known Implementing Classes:

AbstractArrayAssert, AbstractAssert, AbstractBigDecimalAssert, AbstractBooleanArrayAssert, AbstractBooleanAssert, AbstractByteArrayAssert, AbstractByteAssert, AbstractCharacterAssert, AbstractCharArrayAssert, AbstractCharSequenceAssert, AbstractClassAssert, AbstractComparableAssert, AbstractDateAssert, AbstractDoubleArrayAssert, AbstractDoubleAssert, AbstractEnumerableAssert, AbstractFileAssert, AbstractFloatArrayAssert, AbstractFloatAssert, AbstractInputStreamAssert, AbstractIntArrayAssert, AbstractIntegerAssert, AbstractIterableAssert, AbstractIterableSizeAssert, AbstractListAssert, AbstractLongArrayAssert, AbstractLongAssert, AbstractMapAssert, AbstractMapSizeAssert, AbstractObjectArrayAssert, AbstractObjectAssert, AbstractPathAssert, AbstractShortArrayAssert, AbstractShortAssert, AbstractThrowableAssert, AbstractUriAssert, AbstractUrlAssert, BigDecimalAssert, BooleanArrayAssert, BooleanAssert, ByteArrayAssert, ByteAssert, CharacterAssert, CharArrayAssert, CharSequenceAssert, ClassAssert, ClassBasedNavigableIterableAssert, ClassBasedNavigableListAssert, DateAssert, DoubleArrayAssert, DoubleAssert, FactoryBasedNavigableIterableAssert, FactoryBasedNavigableListAssert, FileAssert, FloatArrayAssert, FloatAssert, GenericComparableAssert, InputStreamAssert, IntArrayAssert, IntegerAssert, IterableAssert, IterableSizeAssert, ListAssert, LongArrayAssert, LongAssert, MapAssert, MapSizeAssert, ObjectArrayAssert, ObjectAssert, PathAssert, ShortArrayAssert, ShortAssert, SoftAssertionClassAssert, SoftAssertionMapAssert, StringAssert, ThrowableAssert, UriAssert, UrlAssert
```
public interface Assert<S extends Assert<S,A>,A>
extends Descriptable<S>, ExtensionPoints<S,A>
```
Base contract of all assertion objects: the minimum functionality that any assertion object should provide.

Author:

Yvonne Wang, Alex Ruiz, Nicolas François, Mikhail Mazursky

Method Summary

Methods
Modifier and Type	Method and Description
`AbstractListAssert<?,List<? extends Object>,Object,ObjectAssert<Object>>`	`asList()` Verifies that the actual value is an instance of List, and returns a list assertion, to allow chaining of list-specific assertions from this call.
`AbstractCharSequenceAssert<?,String>`	`asString()` Verifies that the actual value is an instance of String, and returns a String assertion, to allow chaining of String-specific assertions from this call.
`S`	`doesNotHaveSameClassAs(Object other)` Verifies that the actual value does not have the same class as the given object.
`boolean`	`equals(Object obj)` Deprecated. Throws `UnsupportedOperationException` if called. It is easy to accidentally call `equals(Object)` instead of `isEqualTo(Object)`.
`S`	`hasSameClassAs(Object other)` Verifies that the actual value has the same class as the given object.
`S`	`hasToString(String expectedToString)` Verifies that actual `actual.toString()` is equal to the given `String`.
`S`	`isEqualTo(Object expected)` Verifies that the actual value is equal to the given one.
`S`	`isExactlyInstanceOf(Class<?> type)` Verifies that the actual value is exactly an instance of the given type.
`S`	`isIn(Iterable<?> values)` Verifies that the actual value is present in the given values.
`S`	`isIn(Object... values)` Verifies that the actual value is present in the given array of values.
`S`	`isInstanceOf(Class<?> type)` Verifies that the actual value is an instance of the given type.
`S`	`isInstanceOfAny(Class<?>... types)` Verifies that the actual value is an instance of any of the given types.
`S`	`isNotEqualTo(Object other)` Verifies that the actual value is not equal to the given one.
`S`	`isNotExactlyInstanceOf(Class<?> type)` Verifies that the actual value is not exactly an instance of given type.
`S`	`isNotIn(Iterable<?> values)` Verifies that the actual value is not present in the given values.
`S`	`isNotIn(Object... values)` Verifies that the actual value is not present in the given array of values.
`S`	`isNotInstanceOf(Class<?> type)` Verifies that the actual value is not an instance of the given type.
`S`	`isNotInstanceOfAny(Class<?>... types)` Verifies that the actual value is not an instance of any of the given types.
`S`	`isNotNull()` Verifies that the actual value is not `null`.
`S`	`isNotOfAnyClassIn(Class<?>... types)` Verifies that the actual value type is not in given types.
`S`	`isNotSameAs(Object other)` Verifies that the actual value is not the same as the given one, ie using == comparison.
`void`	`isNull()` Verifies that the actual value is `null`.
`S`	`isOfAnyClassIn(Class<?>... types)` Verifies that the actual value type is in given types.
`S`	`isSameAs(Object expected)` Verifies that the actual value is the same as the given one, ie using == comparison.
`S`	`usingComparator(Comparator<? super A> customComparator)` Use given custom comparator instead of relying on actual type A equals method for incoming assertion checks.
`S`	`usingDefaultComparator()` Revert to standard comparison for incoming assertion checks.
`S`	`withRepresentation(Representation representation)` Use the given `Representation` to describe/represent values in AssertJ error messages.
`S`	`withThreadDumpOnError()` In case of assertion error, the thread dump will be printed on `System.err`.

Methods inherited from interface org.assertj.core.api.Descriptable
as, as, describedAs, describedAs

Methods inherited from interface org.assertj.core.api.ExtensionPoints
doesNotHave, has, is, isNot

Method Detail

isEqualTo

S isEqualTo(Object expected)

Verifies that the actual value is equal to the given one.

Example:

 // assertions will pass
 assertThat("abc").isEqualTo("abc");
 assertThat(new HashMap<String, Integer>()).isEqualTo(new HashMap<String, Integer>());
 
 // assertions will fail
 assertThat("abc").isEqualTo("123");
 assertThat(new ArrayList<String>()).isEqualTo(1);

Parameters:: expected - the given value to compare the actual value to.
Returns:: this assertion object.
Throws:: AssertionError - if the actual value is not equal to the given one.

isNotEqualTo

S isNotEqualTo(Object other)

Verifies that the actual value is not equal to the given one.

Example:

 // assertions will pass
 assertThat("abc").isNotEqualTo("123");
 assertThat(new ArrayList<String>()).isNotEqualTo(1);
 
 // assertions will fail
 assertThat("abc").isNotEqualTo("abc");
 assertThat(new HashMap<String, Integer>()).isNotEqualTo(new HashMap<String, Integer>());

Parameters:: other - the given value to compare the actual value to.
Returns:: this assertion object.
Throws:: AssertionError - if the actual value is equal to the given one.

isNull

void isNull()

Verifies that the actual value is null.

Example:

 String value = null;
 // assertion will pass
 assertThat(value).isNull();
 
 // assertions will fail
 assertThat("abc").isNull();
 assertThat(new HashMap<String, Integer>()).isNull();

Throws:: AssertionError - if the actual value is not null.

isNotNull

S isNotNull()

Verifies that the actual value is not null.

Example:

 // assertion will pass
 assertThat("abc").isNotNull();
 assertThat(new HashMap<String, Integer>()).isNotNull();
 
 // assertion will fail
 String value = null;
 assertThat(value).isNotNull();

Returns:: this assertion object.
Throws:: AssertionError - if the actual value is null.

isSameAs

S isSameAs(Object expected)

Verifies that the actual value is the same as the given one, ie using == comparison.

Example:

 // Name is a class with first and last fields, two Names are equals if both first and last are equals.
 Name tyrion = new Name("Tyrion", "Lannister");
 Name alias  = tyrion;
 Name clone  = new Name("Tyrion", "Lannister");
 
 // assertions succeed:
 assertThat(tyrion).isSameAs(alias)
                   .isEqualTo(clone);
                      
 // assertion fails:
 assertThat(tyrion).isSameAs(clone);

Parameters:: expected - the given value to compare the actual value to.
Returns:: this assertion object.
Throws:: AssertionError - if the actual value is not the same as the given one.

isNotSameAs

S isNotSameAs(Object other)

Verifies that the actual value is not the same as the given one, ie using == comparison.

Example:

 // Name is a class with first and last fields, two Names are equals if both first and last are equals.
 Name tyrion = new Name("Tyrion", "Lannister");
 Name alias  = tyrion;
 Name clone  = new Name("Tyrion", "Lannister");
 
 // assertions succeed:
 assertThat(clone).isNotSameAs(tyrion)
                  .isEqualTo(tyrion);
                      
 // assertion fails:
 assertThat(alias).isNotSameAs(tyrion);

Parameters:: other - the given value to compare the actual value to.
Returns:: this assertion object.
Throws:: AssertionError - if the actual value is the same as the given one.

isIn
```
S isIn(Object... values)
```
Verifies that the actual value is present in the given array of values.
Example:
```
 Ring[] elvesRings = new Ring[] { vilya, nenya, narya };
 
 // assertion will pass:
 assertThat(nenya).isIn(elvesRings);
 
 // assertion will fail:
 assertThat(oneRing).isIn(elvesRings);
```
Parameters:
values - the given array to search the actual value in.

Returns:
this assertion object.

Throws:

NullPointerException - if the given array is null.

IllegalArgumentException - if the given array is empty.

AssertionError - if the actual value is not present in the given array.

isNotIn
```
S isNotIn(Object... values)
```
Verifies that the actual value is not present in the given array of values.
Example:
```
 Ring[] elvesRings = new Ring[] { vilya, nenya, narya };
 
 // assertion will pass:
 assertThat(oneRing).isNotIn(elvesRings);
 
 // assertion will fail:
 assertThat(nenya).isNotIn(elvesRings);
```
Parameters:
values - the given array to search the actual value in.

Returns:
this assertion object.

Throws:

NullPointerException - if the given array is null.

IllegalArgumentException - if the given array is empty.

AssertionError - if the actual value is present in the given array.

isIn
```
S isIn(Iterable<?> values)
```
Verifies that the actual value is present in the given values.
Example:
```
 Iterable<Ring> elvesRings = newArrayList(vilya, nenya, narya);
 
 // assertion will pass:
 assertThat(nenya).isIn(elvesRings);
 
 // assertion will fail:
 assertThat(oneRing).isIn(elvesRings);
```
Parameters:
values - the given iterable to search the actual value in.

Returns:
this assertion object.

Throws:

NullPointerException - if the given collection is null.

IllegalArgumentException - if the given collection is empty.

AssertionError - if the actual value is not present in the given collection.

isNotIn
```
S isNotIn(Iterable<?> values)
```
Verifies that the actual value is not present in the given values.
Example:
```
 Iterable<Ring> elvesRings = newArrayList(vilya, nenya, narya);
 
 // assertion will pass:
 assertThat(oneRing).isNotIn(elvesRings);
 
 // assertion will fail:
 assertThat(nenya).isNotIn(elvesRings);
```
Parameters:
values - the given iterable to search the actual value in.

Returns:
this assertion object.

Throws:

NullPointerException - if the given collection is null.

IllegalArgumentException - if the given collection is empty.

AssertionError - if the actual value is present in the given collection.

usingComparator
```
S usingComparator(Comparator<? super A> customComparator)
```
Use given custom comparator instead of relying on actual type A equals method for incoming assertion checks.
Custom comparator is bound to assertion instance, meaning that if a new assertion is created, it will use default comparison strategy. Examples :
```
 // frodo and sam are instances of Character with Hobbit race (obviously :).
 // raceComparator implements Comparator<Character> 
 assertThat(frodo).usingComparator(raceComparator).isEqualTo(sam);
```
Parameters:
customComparator - the comparator to use for incoming assertion checks.

Returns:
this assertion object.

Throws:

NullPointerException - if the given comparator is null.

usingDefaultComparator
```
S usingDefaultComparator()
```
Revert to standard comparison for incoming assertion checks.
This method should be used to disable a custom comparison strategy set by calling usingComparator(Comparator).

Returns:
this assertion object.

isInstanceOf

S isInstanceOf(Class<?> type)

Verifies that the actual value is an instance of the given type.

Example:

 // assertions will pass
 assertThat("abc").isInstanceOf(String.class);
 assertThat(new HashMap<String, Integer>()).isInstanceOf(HashMap.class);
 assertThat(new HashMap<String, Integer>()).isInstanceOf(Map.class);
 
 // assertions will fail
 assertThat(1).isInstanceOf(String.class);
 assertThat(new ArrayList<String>()).isInstanceOf(LinkedList.class);

Parameters:: type - the type to check the actual value against.
Returns:: this assertion object.
Throws:: NullPointerException - if the given type is null.; AssertionError - if the actual value is null.; AssertionError - if the actual value is not an instance of the given type.

isInstanceOfAny

S isInstanceOfAny(Class<?>... types)

Verifies that the actual value is an instance of any of the given types.

Example:

 // assertions will pass
 assertThat("abc").isInstanceOfAny(String.class, Integer.class);
 assertThat(new ArrayList<String>()).isInstanceOfAny(LinkedList.class, ArrayList.class);
 assertThat(new HashMap<String, Integer>()).isInstanceOfAny(TreeMap.class, Map.class);
 
 // assertions will fail
 assertThat(1).isInstanceOfAny(Double.class, Float.class);
 assertThat(new ArrayList<String>()).isInstanceOfAny(LinkedList.class, Vector.class);

Parameters:: types - the types to check the actual value against.
Returns:: this assertion object.
Throws:: AssertionError - if the actual value is null.; AssertionError - if the actual value is not an instance of any of the given types.; NullPointerException - if the given array of types is null.; NullPointerException - if the given array of types contains nulls.

isNotInstanceOf

S isNotInstanceOf(Class<?> type)

Verifies that the actual value is not an instance of the given type.

Example:

 // assertions will pass
 assertThat(1).isNotInstanceOf(Double.class);
 assertThat(new ArrayList<String>()).isNotInstanceOf(LinkedList.class);
 
 // assertions will fail
 assertThat("abc").isNotInstanceOf(String.class);
 assertThat(new HashMap<String, Integer>()).isNotInstanceOf(HashMap.class);
 assertThat(new HashMap<String, Integer>()).isNotInstanceOf(Map.class);

Parameters:: type - the type to check the actual value against.
Returns:: this assertion object.
Throws:: NullPointerException - if the given type is null.; AssertionError - if the actual value is null.; AssertionError - if the actual value is an instance of the given type.

isNotInstanceOfAny

S isNotInstanceOfAny(Class<?>... types)

Verifies that the actual value is not an instance of any of the given types.

Example:

 // assertions will pass
 assertThat(1).isNotInstanceOfAny(Double.class, Float.class);
 assertThat(new ArrayList<String>()).isNotInstanceOfAny(LinkedList.class, Vector.class);
 
 // assertions will fail
 assertThat(1).isNotInstanceOfAny(Double.class, Integer.class);
 assertThat(new ArrayList<String>()).isNotInstanceOfAny(LinkedList.class, ArrayList.class);
 assertThat(new HashMap<String, Integer>()).isNotInstanceOfAny(TreeMap.class, Map.class);

Parameters:: types - the types to check the actual value against.
Returns:: this assertion object.
Throws:: AssertionError - if the actual value is null.; AssertionError - if the actual value is an instance of any of the given types.; NullPointerException - if the given array of types is null.; NullPointerException - if the given array of types contains nulls.

hasSameClassAs

S hasSameClassAs(Object other)

Verifies that the actual value has the same class as the given object.

Example:

 // assertions will pass
 assertThat(1).hasSameClassAs(2);
 assertThat("abc").hasSameClassAs("123");
 assertThat(new ArrayList<String>()).hasSameClassAs(new ArrayList<Integer>());
 
 // assertions will fail
 assertThat(1).hasSameClassAs("abc");
 assertThat(new ArrayList<String>()).hasSameClassAs(new LinkedList<String>());

Parameters:: other - the object to check type against.
Returns:: this assertion object.
Throws:: AssertionError - if the actual has not the same type has the given object.; NullPointerException - if the actual value is null.; NullPointerException - if the given object is null.

hasToString
```
S hasToString(String expectedToString)
```
Verifies that actual actual.toString() is equal to the given String.
Example :
```
 CartoonCaracter homer = new CartoonCaracter("Homer");

 // Instead of writing ...  
 assertThat(homer.toString()).isEqualTo("Homer");
 // ... you can simply write: 
 assertThat(homer).hasToString("Homer");
```
Parameters:
expectedToString - the expected String description of actual.

Returns:
this assertion object.

Throws:

AssertionError - if actual.toString() result is not to the given String.

AssertionError - if actual is null.

doesNotHaveSameClassAs

S doesNotHaveSameClassAs(Object other)

Verifies that the actual value does not have the same class as the given object.

Example:

 // assertions will pass
 assertThat(1).doesNotHaveSameClassAs("abc");
 assertThat(new ArrayList<String>()).doesNotHaveSameClassAs(new LinkedList<String>());
 
 // assertions will fail
 assertThat(1).doesNotHaveSameClassAs(2);
 assertThat("abc").doesNotHaveSameClassAs("123");
 assertThat(new ArrayList<String>()).doesNotHaveSameClassAs(new ArrayList<Integer>());

Parameters:: other - the object to check type against.
Returns:: this assertion object.
Throws:: AssertionError - if the actual has the same type has the given object.; NullPointerException - if the actual value is null.; NullPointerException - if the given object is null.

isExactlyInstanceOf

S isExactlyInstanceOf(Class<?> type)

Verifies that the actual value is exactly an instance of the given type.

Example:

 // assertions will pass
 assertThat("abc").isExactlyInstanceOf(String.class);
 assertThat(new ArrayList<String>()).isExactlyInstanceOf(ArrayList.class);
 assertThat(new HashMap<String, Integer>()).isExactlyInstanceOf(HashMap.class);
 
 // assertions will fail
 assertThat(1).isExactlyInstanceOf(String.class);
 assertThat(new ArrayList<String>()).isExactlyInstanceOf(List.class);
 assertThat(new HashMap<String, Integer>()).isExactlyInstanceOf(Map.class);

Parameters:: type - the type to check the actual value against.
Returns:: this assertion object.
Throws:: AssertionError - if the actual is not exactly an instance of given type.; NullPointerException - if the actual value is null.; NullPointerException - if the given object is null.

isNotExactlyInstanceOf

S isNotExactlyInstanceOf(Class<?> type)

Verifies that the actual value is not exactly an instance of given type.

Example:

 // assertions will pass
 assertThat(1).isNotExactlyInstanceOf(String.class);
 assertThat(new ArrayList<String>()).isNotExactlyInstanceOf(List.class);
 assertThat(new HashMap<String, Integer>()).isNotExactlyInstanceOf(Map.class);
 
 // assertions will fail
 assertThat("abc").isNotExactlyInstanceOf(String.class);
 assertThat(new ArrayList<String>()).isNotExactlyInstanceOf(ArrayList.class);
 assertThat(new HashMap<String, Integer>()).isNotExactlyInstanceOf(HashMap.class);

Parameters:: type - the type to check the actual value against.
Returns:: this assertion object.
Throws:: AssertionError - if the actual is exactly an instance of given type.; NullPointerException - if the actual value is null.; NullPointerException - if the given object is null.

isOfAnyClassIn

S isOfAnyClassIn(Class<?>... types)

Verifies that the actual value type is in given types.

Example:

 // assertions will pass
 assertThat(new HashMap<String, Integer>()).isOfAnyClassIn(HashMap.class, TreeMap.class);
 assertThat(new ArrayList<String>()).isOfAnyClassIn(ArrayList.class, LinkedList.class);
 
 // assertions will fail
 assertThat(new HashMap<String, Integer>()).isOfAnyClassIn(TreeMap.class, Map.class);
 assertThat(new ArrayList<String>()).isOfAnyClassIn(LinkedList.class, List.class);

Parameters:: types - the types to check the actual value against.
Returns:: this assertion object.
Throws:: AssertionError - if the actual value type is not in given type.; NullPointerException - if the actual value is null.; NullPointerException - if the given types is null.

isNotOfAnyClassIn

S isNotOfAnyClassIn(Class<?>... types)

Verifies that the actual value type is not in given types.

Example:

 // assertions will pass
 assertThat(new HashMap<String, Integer>()).isNotOfAnyClassIn(Map.class, TreeMap.class);
 assertThat(new ArrayList<String>()).isNotOfAnyClassIn(LinkedList.class, List.class);
 
 // assertions will fail
 assertThat(new HashMap<String, Integer>()).isNotOfAnyClassIn(HashMap.class, TreeMap.class);
 assertThat(new ArrayList<String>()).isNotOfAnyClassIn(ArrayList.class, LinkedList.class);

Parameters:: types - the types to check the actual value against.
Returns:: this assertion object.
Throws:: AssertionError - if the actual value type is in given types.; NullPointerException - if the actual value is null.; NullPointerException - if the given types is null.

asList

AbstractListAssert<?,List<? extends Object>,Object,ObjectAssert<Object>> asList()

Verifies that the actual value is an instance of List, and returns a list assertion, to allow chaining of list-specific assertions from this call.

Example :

 Object sortedListAsObject = Arrays.asList(1, 2, 3);

 // assertion will pass
 assertThat(sortedListAsObject).asList().isSorted();
 
 Object unsortedListAsObject = Arrays.asList(3, 1, 2);
 
 // assertion will fail
 assertThat(unsortedListAsObject).asList().isSorted();

Returns:: a list assertion object

asString

AbstractCharSequenceAssert<?,String> asString()

Verifies that the actual value is an instance of String, and returns a String assertion, to allow chaining of String-specific assertions from this call.

Example :

 Object stringAsObject = "hello world";

 // assertion will pass
 assertThat(stringAsObject).asString().contains("hello");
 
 // assertion will fail
 assertThat(stringAsObject).asString().contains("holla");

Returns:: a string assertion object

equals
```
@Deprecated
boolean equals(Object obj)
```
Deprecated. Throws UnsupportedOperationException if called. It is easy to accidentally call equals(Object) instead of isEqualTo(Object).

Overrides:

equals in class Object

Throws:

UnsupportedOperationException - if this method is called.

withThreadDumpOnError

S withThreadDumpOnError()

In case of assertion error, the thread dump will be printed on System.err.

Example :

 assertThat("Messi").withThreadDumpOnError().isEqualTo("Ronaldo");

will print the thread dump, something looking like:

"JDWP Command Reader"
 	java.lang.Thread.State: RUNNABLE

 "JDWP Event Helper Thread"
 	java.lang.Thread.State: RUNNABLE

 "JDWP Transport Listener: dt_socket"
 	java.lang.Thread.State: RUNNABLE

 "Signal Dispatcher"
 	java.lang.Thread.State: RUNNABLE

 "Finalizer"
 	java.lang.Thread.State: WAITING
 		at java.lang.Object.wait(Native Method)
 		at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:135)
 		at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:151)
 		at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:189)

 "Reference Handler"
 	java.lang.Thread.State: WAITING
 		at java.lang.Object.wait(Native Method)
 		at java.lang.Object.wait(Object.java:503)
 		at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:133)

 "main"
 	java.lang.Thread.State: RUNNABLE
 		at sun.management.ThreadImpl.dumpThreads0(Native Method)
 		at sun.management.ThreadImpl.dumpAllThreads(ThreadImpl.java:446)
 		at org.assertj.core.internal.Failures.threadDumpDescription(Failures.java:193)
 		at org.assertj.core.internal.Failures.printThreadDumpIfNeeded(Failures.java:141)
 		at org.assertj.core.internal.Failures.failure(Failures.java:91)
 		at org.assertj.core.internal.Objects.assertEqual(Objects.java:314)
 		at org.assertj.core.api.AbstractAssert.isEqualTo(AbstractAssert.java:198)
 		at org.assertj.examples.ThreadDumpOnErrorExample.main(ThreadDumpOnErrorExample.java:28)

Returns:: this assertion object.

withRepresentation

S withRepresentation(Representation representation)

Use the given Representation to describe/represent values in AssertJ error messages.

The usual to introduce a new Representation is to extend StandardRepresentation and override any existing toStringOf methods that don't suit you, as an example you could control Date format by overriding StandardRepresentation.toStringOf(Date)).

You can also control other types format by overriding StandardRepresentation.toStringOf(Object)) calling your formatting method first and then fallback to the default represention by calling super.toStringOf(Object).

Example :

 private class Example {}

 private class CustomRepresentation extends StandardRepresentation {
 
   // override needed to hook specific formatting  
   @Override
   public String toStringOf(Object o) {
     if (o instanceof Example) return "Example";
     // fallback to default formatting.  
     return super.toStringOf(o);
   }
   
   // change String representation  
   @Override
   protected String toStringOf(String s) {
     return "$" + s + "$";
   }
 }
 
 // next assertion fails with error : "expected:<[null]> but was:<[Example]>"
 Example example = new Example();
 assertThat(example).withRepresentation(new CustomRepresentation())
                    .isNull(); // example is not null !
 
 // next assertion fails ... 
 assertThat("foo").withRepresentation(new CustomRepresentation())
                  .startsWith("bar");
 // ... with error :
 Expecting:
  <$foo$>
 to start with:
  <$bar$>

Parameters:: representation - Describe/represent values in AssertJ error messages.
Returns:

Interface Assert<S extends Assert<S,A>,A>

Method Summary

Methods inherited from interface org.assertj.core.api.Descriptable

Methods inherited from interface org.assertj.core.api.ExtensionPoints

Method Detail

isEqualTo

isNotEqualTo

isNull

isNotNull

isSameAs

isNotSameAs

isIn

isNotIn

isIn

isNotIn

usingComparator

usingDefaultComparator

isInstanceOf

isInstanceOfAny

isNotInstanceOf

isNotInstanceOfAny

hasSameClassAs

hasToString

doesNotHaveSameClassAs

isExactlyInstanceOf

isNotExactlyInstanceOf

isOfAnyClassIn

isNotOfAnyClassIn

asList

asString

equals

withThreadDumpOnError

withRepresentation