com.google.common.truth

Class Truth

java.lang.Object

com.google.common.truth.Truth

public final class Truth
extends Object

The primary entry point for Truth, a fluent framework for test assertions.

Compare these example JUnit assertions...

 assertEquals(b, a);
 assertTrue(c);
 assertTrue(d.contains(a));
 assertTrue(d.contains(a) && d.contains(b));
 assertTrue(d.contains(a) || d.contains(b) || d.contains(c));
 

...to their Truth equivalents...

 assertThat(a).isEqualTo(b);
 assertThat(c).isTrue();
 assertThat(d).contains(a);
 assertThat(d).containsAllOf(a, b);
 assertThat(d).containsAnyOf(a, b, c);
 

Advantages of Truth:

• aligns all the "actual" values on the left
• produces more detailed failure messages
• provides richer operations (like IterableSubject.containsExactly(java.lang.Object...))

TODO(cpovirk): Link to a doc about the full assertion chain.

For people extending Truth

TODO(cpovirk): Link to a doc about custom subjects.

TODO(cpovirk): Also talk about FailureStrategy.

Author:

David Saff, Christian Gruber (cgruber@israfil.net)

Field Summary

Fields

Modifier and Type	Field and Description
static FailureStrategy	THROW_ASSERTION_ERROR

Method Summary

Modifier and Type	Method and Description
static StandardSubjectBuilder	assert_() Begins a call chain with the fluent Truth API.
static <CustomSubjectBuilderT extends CustomSubjectBuilder> CustomSubjectBuilderT	assertAbout(CustomSubjectBuilderFactory<CustomSubjectBuilderT> factory) A generic, advanced method of extension of Truth to new types, which is documented on CustomSubjectBuilder.
static <V extends AbstractDelegatedVerb> V	assertAbout(DelegatedVerbFactory<V> factory) Deprecated. When you switch from implementing DelegatedVerbFactory to implementing CustomSubjectBuilderFactory, you'll switch from this overload to the overload that accepts a CustomSubjectBuilderFactory.
static <S extends Subject<S,T>,T> SimpleSubjectBuilder<S,T>	assertAbout(SubjectFactory<S,T> factory) The recommended method of extension of Truth to new types, which is documented in com.google.common.truth.delegation.DelegationTest.
static AtomicLongMapSubject	assertThat(com.google.common.util.concurrent.AtomicLongMap<?> target)
static BigDecimalSubject	assertThat(BigDecimal target)
static BooleanSubject	assertThat(Boolean target)
static PrimitiveBooleanArraySubject	assertThat(boolean[] target)
static PrimitiveByteArraySubject	assertThat(byte[] target)
static PrimitiveCharArraySubject	assertThat(char[] target)
static ClassSubject	assertThat(Class<?> target)
static DoubleSubject	assertThat(Double target)
static PrimitiveDoubleArraySubject	assertThat(double[] target)
static FloatSubject	assertThat(Float target)
static PrimitiveFloatArraySubject	assertThat(float[] target)
static PrimitiveIntArraySubject	assertThat(int[] target)
static IntegerSubject	assertThat(Integer target)
static IterableSubject	assertThat(Iterable<?> target)
static ListMultimapSubject	assertThat(com.google.common.collect.ListMultimap<?,?> target)
static LongSubject	assertThat(Long target)
static PrimitiveLongArraySubject	assertThat(long[] target)
static MapSubject	assertThat(Map<?,?> target)
static MultimapSubject	assertThat(com.google.common.collect.Multimap<?,?> target)
static MultisetSubject	assertThat(com.google.common.collect.Multiset<?> target)
static Subject<DefaultSubject,Object>	assertThat(Object target)
static GuavaOptionalSubject	assertThat(com.google.common.base.Optional<?> target)
static SetMultimapSubject	assertThat(com.google.common.collect.SetMultimap<?,?> target)
static PrimitiveShortArraySubject	assertThat(short[] target)
static SortedMapSubject	assertThat(SortedMap<?,?> target)
static SortedSetSubject	assertThat(SortedSet<?> target)
static StringSubject	assertThat(String target)
static <T extends Comparable<?>> ComparableSubject<?,T>	assertThat(T target)
static <T> ObjectArraySubject<T>	assertThat(T[] target)
static TableSubject	assertThat(com.google.common.collect.Table<?,?,?> target)
static ThrowableSubject	assertThat(Throwable target)
static StandardSubjectBuilder	assertWithMessage(String messageToPrepend) Returns a TestVerb that will prepend the given message to the failure message in the event of a test failure.
static StandardSubjectBuilder	assertWithMessage(String format, Object... args) Returns a TestVerb that will prepend the formatted message using the specified arguments to the failure message in the event of a test failure.

Methods inherited from class java.lang.Object

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

Field Detail

THROW_ASSERTION_ERROR

public static final FailureStrategy THROW_ASSERTION_ERROR

Method Detail

assert_

public static StandardSubjectBuilder assert_()

Begins a call chain with the fluent Truth API. If the check made by the chain fails, it will throw AssertionError.

assertWithMessage

public static StandardSubjectBuilder assertWithMessage(String messageToPrepend)

Returns a TestVerb that will prepend the given message to the failure message in the event of a test failure.

assertWithMessage

public static StandardSubjectBuilder assertWithMessage(String format,
                                                       Object... args)

Returns a TestVerb that will prepend the formatted message using the specified arguments to the failure message in the event of a test failure.

Note: The failure message template string only supports the "%s" specifier, not the full range of Formatter specifiers.

Throws:

IllegalArgumentException - if the number of placeholders in the format string does not equal the number of given arguments

assertAbout

public static <S extends Subject<S,T>,T> SimpleSubjectBuilder<S,T> assertAbout(SubjectFactory<S,T> factory)

The recommended method of extension of Truth to new types, which is documented in com.google.common.truth.delegation.DelegationTest.

Parameters:

factory - a SubjectFactory implementation

Returns:

A custom verb for the type returned by the SubjectFactory

assertAbout

public static <CustomSubjectBuilderT extends CustomSubjectBuilder> CustomSubjectBuilderT assertAbout(CustomSubjectBuilderFactory<CustomSubjectBuilderT> factory)

A generic, advanced method of extension of Truth to new types, which is documented on CustomSubjectBuilder. Extension creators should prefer SubjectFactory if possible.

assertAbout

@Deprecated
public static <V extends AbstractDelegatedVerb> V assertAbout(DelegatedVerbFactory<V> factory)

Deprecated. When you switch from implementing DelegatedVerbFactory to implementing CustomSubjectBuilderFactory, you'll switch from this overload to the overload that accepts a CustomSubjectBuilderFactory.

A generic, advanced method of extension of Truth to new types, which is documented on DelegatedVerbFactory. Extension creators should prefer SubjectFactory if possible.

Type Parameters:

V - the type of AbstractDelegatedVerb to return

Parameters:

factory - a DelegatedVerbFactory<V> implementation

Returns:

A custom verb of type <V>

assertThat

public static <T extends Comparable<?>> ComparableSubject<?,T> assertThat(@Nullable
                                                                          T target)

assertThat

public static BigDecimalSubject assertThat(@Nullable
                                           BigDecimal target)

assertThat

public static Subject<DefaultSubject,Object> assertThat(@Nullable
                                                        Object target)

assertThat

@GwtIncompatible(value="ClassSubject.java")
public static ClassSubject assertThat(@Nullable
                                                                                  Class<?> target)

assertThat

public static ThrowableSubject assertThat(@Nullable
                                          Throwable target)

assertThat

public static LongSubject assertThat(@Nullable
                                     Long target)

assertThat

public static DoubleSubject assertThat(@Nullable
                                       Double target)

assertThat

public static FloatSubject assertThat(@Nullable
                                      Float target)

assertThat

public static IntegerSubject assertThat(@Nullable
                                        Integer target)

assertThat

public static BooleanSubject assertThat(@Nullable
                                        Boolean target)

assertThat

public static StringSubject assertThat(@Nullable
                                       String target)

assertThat

public static IterableSubject assertThat(@Nullable
                                         Iterable<?> target)

assertThat

public static SortedSetSubject assertThat(@Nullable
                                          SortedSet<?> target)

assertThat

public static <T> ObjectArraySubject<T> assertThat(@Nullable
                                                   T[] target)

assertThat

public static PrimitiveBooleanArraySubject assertThat(@Nullable
                                                      boolean[] target)

assertThat

public static PrimitiveShortArraySubject assertThat(@Nullable
                                                    short[] target)

assertThat

public static PrimitiveIntArraySubject assertThat(@Nullable
                                                  int[] target)

assertThat

public static PrimitiveLongArraySubject assertThat(@Nullable
                                                   long[] target)

assertThat

public static PrimitiveByteArraySubject assertThat(@Nullable
                                                   byte[] target)

assertThat

public static PrimitiveCharArraySubject assertThat(@Nullable
                                                   char[] target)

assertThat

public static PrimitiveFloatArraySubject assertThat(@Nullable
                                                    float[] target)

assertThat

public static PrimitiveDoubleArraySubject assertThat(@Nullable
                                                     double[] target)

assertThat

public static GuavaOptionalSubject assertThat(@Nullable
                                              com.google.common.base.Optional<?> target)

assertThat

public static MapSubject assertThat(@Nullable
                                    Map<?,?> target)

assertThat

public static SortedMapSubject assertThat(@Nullable
                                          SortedMap<?,?> target)

assertThat

public static MultimapSubject assertThat(@Nullable
                                         com.google.common.collect.Multimap<?,?> target)

assertThat

public static ListMultimapSubject assertThat(@Nullable
                                             com.google.common.collect.ListMultimap<?,?> target)

assertThat

public static SetMultimapSubject assertThat(@Nullable
                                            com.google.common.collect.SetMultimap<?,?> target)

assertThat

public static MultisetSubject assertThat(@Nullable
                                         com.google.common.collect.Multiset<?> target)

assertThat

public static TableSubject assertThat(@Nullable
                                      com.google.common.collect.Table<?,?,?> target)

assertThat

public static AtomicLongMapSubject assertThat(@Nullable
                                              com.google.common.util.concurrent.AtomicLongMap<?> target)