com.google.common.truth

Class Truth

java.lang.Object

com.google.common.truth.Truth

@CheckReturnValue
public final class Truth
extends Object

Truth - a proposition framework for tests, supporting JUnit style assertion and assumption semantics in a fluent style.

Truth is the simplest entry point class. A developer can statically import the assertThat() method to get easy access to the library's capabilities. Then, instead of writing:

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

one would write:

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

Tests should be easier to read, and flow more clearly.

Often, tests assert a relationship between a value produced by the test (the "actual" value) and some reference value (the "expected" value). It is strongly recommended that the actual value is made the subject of the assertion. For example:

   assertThat(actual).isEqualTo(expected);  // recommended
   assertThat(expected).isEqualTo(actual);  // not recommended
   assertThat(actual).isIn(expectedPossibilities);  // recommended
   assertThat(expectedPossibilities).contains(actual);  // not recommended

Author:

David Saff, Christian Gruber ([email protected])

Field Summary

Fields

Modifier and Type	Field and Description
static FailureStrategy	THROW_ASSERTION_ERROR

Constructor Summary

Constructors

Constructor and Description
Truth()

Method Summary

Methods

Modifier and Type	Method and Description
static TestVerb	assert_()
static <S extends Subject<S,T>,T,SF extends SubjectFactory<S,T>> AbstractVerb.DelegatedVerb<S,T>	assertAbout(SF factory) The recommended method of extension of Truth to new types, which is documented in com.google.common.truth.delegation.DelegationTest.
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 PrimitiveFloatArraySubject	assertThat(float[] target)
static PrimitiveIntArraySubject	assertThat(int[] target)
static IntegerSubject	assertThat(Integer target)
static <T,C extends Iterable<T>> IterableSubject<? extends IterableSubject<?,T,C>,T,C>	assertThat(Iterable<T> target)
static <K,V,M extends com.google.common.collect.ListMultimap<K,V>> ListMultimapSubject<? extends ListMultimapSubject<?,K,V,M>,K,V,M>	assertThat(com.google.common.collect.ListMultimap<K,V> target)
static LongSubject	assertThat(Long target)
static PrimitiveLongArraySubject	assertThat(long[] target)
static MapSubject	assertThat(Map<?,?> target)
static <K,V,M extends com.google.common.collect.Multimap<K,V>> MultimapSubject<? extends MultimapSubject<?,K,V,M>,K,V,M>	assertThat(com.google.common.collect.Multimap<K,V> target)
static <E,M extends com.google.common.collect.Multiset<E>> MultisetSubject<? extends MultisetSubject<?,E,M>,E,M>	assertThat(com.google.common.collect.Multiset<E> target)
static Subject<DefaultSubject,Object>	assertThat(Object target)
static <T> OptionalSubject<T>	assertThat(com.google.common.base.Optional<T> target)
static <K,V,M extends com.google.common.collect.SetMultimap<K,V>> SetMultimapSubject<? extends SetMultimapSubject<?,K,V,M>,K,V,M>	assertThat(com.google.common.collect.SetMultimap<K,V> 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 TestVerb	assertWithMessage(String messageToPrepend) Returns a TestVerb that will prepend the given message 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

Constructor Detail

Truth

public Truth()

Method Detail

assert_

public static TestVerb assert_()

assertWithMessage

public static TestVerb assertWithMessage(String messageToPrepend)

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

assertAbout

public static <S extends Subject<S,T>,T,SF extends SubjectFactory<S,T>> AbstractVerb.DelegatedVerb<S,T> assertAbout(SF 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

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 IntegerSubject assertThat(@Nullable
                        Integer target)

assertThat

public static BooleanSubject assertThat(@Nullable
                        Boolean target)

assertThat

public static StringSubject assertThat(@Nullable
                       String target)

assertThat

public static <T,C extends Iterable<T>> IterableSubject<? extends IterableSubject<?,T,C>,T,C> assertThat(@Nullable
                                                                                         Iterable<T> target)

assertThat

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

assertThat

public static PrimitiveBooleanArraySubject assertThat(@Nullable
                                      boolean[] 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 <T> OptionalSubject<T> assertThat(@Nullable
                                com.google.common.base.Optional<T> target)

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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