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 Deprecated. If you are passing this to a Subject constructor, instead call assertAbout(SubjectFactory).that(...), passing its associated SubjectFactory (which you might need to create). If you are calling fail on this object directly, instead use assert_().fail(), or throw new AssertionError() directly.

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(CustomSubjectBuilder.Factory<CustomSubjectBuilderT> factory) A generic, advanced method of extension of Truth to new types, which is documented on CustomSubjectBuilder.
static <CustomSubjectBuilderT extends CustomSubjectBuilder> CustomSubjectBuilderT	assertAbout(CustomSubjectBuilderFactory<CustomSubjectBuilderT> factory) Deprecated. When you switch from CustomSubjectBuilderFactory to CustomSubjectBuilder.Factory, you'll switch from this overload to the CustomSubjectBuilder.Factory overload.
static <S extends Subject<S,T>,T> SimpleSubjectBuilder<S,T>	assertAbout(Subject.Factory<S,T> factory) Given a factory for some Subject class, returns a builder whose that(actual) method creates instances of that class.
static <S extends Subject<S,T>,T> SimpleSubjectBuilder<S,T>	assertAbout(SubjectFactory<S,T> factory) Deprecated. When you switch from SubjectFactory to Subject.Factory, you'll switch from this overload to the Subject.Factory overload.
static AtomicLongMapSubject	assertThat(com.google.common.util.concurrent.AtomicLongMap<?> actual)
static BigDecimalSubject	assertThat(BigDecimal actual)
static BooleanSubject	assertThat(Boolean actual)
static PrimitiveBooleanArraySubject	assertThat(boolean[] actual)
static PrimitiveByteArraySubject	assertThat(byte[] actual)
static PrimitiveCharArraySubject	assertThat(char[] actual)
static ClassSubject	assertThat(Class<?> actual)
static DoubleSubject	assertThat(Double actual)
static PrimitiveDoubleArraySubject	assertThat(double[] actual)
static FloatSubject	assertThat(Float actual)
static PrimitiveFloatArraySubject	assertThat(float[] actual)
static PrimitiveIntArraySubject	assertThat(int[] actual)
static IntegerSubject	assertThat(Integer actual)
static IterableSubject	assertThat(Iterable<?> actual)
static ListMultimapSubject	assertThat(com.google.common.collect.ListMultimap<?,?> actual)
static LongSubject	assertThat(Long actual)
static PrimitiveLongArraySubject	assertThat(long[] actual)
static MapSubject	assertThat(Map<?,?> actual)
static MultimapSubject	assertThat(com.google.common.collect.Multimap<?,?> actual)
static MultisetSubject	assertThat(com.google.common.collect.Multiset<?> actual)
static Subject<DefaultSubject,Object>	assertThat(Object actual)
static GuavaOptionalSubject	assertThat(com.google.common.base.Optional<?> actual)
static SetMultimapSubject	assertThat(com.google.common.collect.SetMultimap<?,?> actual)
static PrimitiveShortArraySubject	assertThat(short[] actual)
static SortedMapSubject	assertThat(SortedMap<?,?> actual)
static SortedSetSubject	assertThat(SortedSet<?> actual)
static StringSubject	assertThat(String actual)
static <T extends Comparable<?>> ComparableSubject<?,T>	assertThat(T actual)
static <T> ObjectArraySubject<T>	assertThat(T[] actual)
static TableSubject	assertThat(com.google.common.collect.Table<?,?,?> actual)
static ThrowableSubject	assertThat(Throwable actual)
static StandardSubjectBuilder	assertWithMessage(String messageToPrepend) Returns a StandardSubjectBuilder 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 StandardSubjectBuilder 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

@Deprecated
public static final FailureStrategy THROW_ASSERTION_ERROR

Deprecated. If you are passing this to a Subject constructor, instead call assertAbout(SubjectFactory).that(...), passing its associated SubjectFactory (which you might need to create). If you are calling fail on this object directly, instead use assert_().fail(), or throw new AssertionError() directly.

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 StandardSubjectBuilder 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 StandardSubjectBuilder 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

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

Deprecated. When you switch from SubjectFactory to Subject.Factory, you'll switch from this overload to the Subject.Factory overload.

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 <S extends Subject<S,T>,T> SimpleSubjectBuilder<S,T> assertAbout(Subject.Factory<S,T> factory)

Given a factory for some Subject class, returns a builder whose that(actual) method creates instances of that class.

assertAbout

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

Deprecated. When you switch from CustomSubjectBuilderFactory to CustomSubjectBuilder.Factory, you'll switch from this overload to the CustomSubjectBuilder.Factory overload.

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

assertAbout

public static <CustomSubjectBuilderT extends CustomSubjectBuilder> CustomSubjectBuilderT assertAbout(CustomSubjectBuilder.Factory<CustomSubjectBuilderT> factory)

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

assertThat

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

assertThat

public static BigDecimalSubject assertThat(@Nullable
                                           BigDecimal actual)

assertThat

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

assertThat

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

assertThat

public static ThrowableSubject assertThat(@Nullable
                                          Throwable actual)

assertThat

public static LongSubject assertThat(@Nullable
                                     Long actual)

assertThat

public static DoubleSubject assertThat(@Nullable
                                       Double actual)

assertThat

public static FloatSubject assertThat(@Nullable
                                      Float actual)

assertThat

public static IntegerSubject assertThat(@Nullable
                                        Integer actual)

assertThat

public static BooleanSubject assertThat(@Nullable
                                        Boolean actual)

assertThat

public static StringSubject assertThat(@Nullable
                                       String actual)

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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