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...))

For more information about the methods in this class, see this FAQ entry.

For people extending Truth

The most common way to extend Truth is to write a custom Subject. (The other, much less common way is to write a custom FailureStrategy.) For more information, visit those types' docs.

Author:

David Saff, Christian Gruber ([email protected])

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 <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 AtomicLongMapSubject	assertThat(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(ListMultimap<?,?> actual)
static LongSubject	assertThat(Long actual)
static PrimitiveLongArraySubject	assertThat(long[] actual)
static MapSubject	assertThat(Map<?,?> actual)
static MultimapSubject	assertThat(Multimap<?,?> actual)
static MultisetSubject	assertThat(Multiset<?> actual)
static Subject<DefaultSubject,Object>	assertThat(Object actual)
static GuavaOptionalSubject	assertThat(Optional<?> actual)
static SetMultimapSubject	assertThat(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(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

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 arguments will be substituted into the format template using Strings.lenientFormat. Note this only supports the %s specifier.

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(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

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(@NullableDecl
                                                                          T actual)

assertThat

public static BigDecimalSubject assertThat(@NullableDecl
                                           BigDecimal actual)

assertThat

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

assertThat

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

assertThat

public static ThrowableSubject assertThat(@NullableDecl
                                          Throwable actual)

assertThat

public static LongSubject assertThat(@NullableDecl
                                     Long actual)

assertThat

public static DoubleSubject assertThat(@NullableDecl
                                       Double actual)

assertThat

public static FloatSubject assertThat(@NullableDecl
                                      Float actual)

assertThat

public static IntegerSubject assertThat(@NullableDecl
                                        Integer actual)

assertThat

public static BooleanSubject assertThat(@NullableDecl
                                        Boolean actual)

assertThat

public static StringSubject assertThat(@NullableDecl
                                       String actual)

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

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

assertThat

public static GuavaOptionalSubject assertThat(@NullableDecl
                                              Optional<?> actual)

assertThat

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

assertThat

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

assertThat

public static MultimapSubject assertThat(@NullableDecl
                                         Multimap<?,?> actual)

assertThat

public static ListMultimapSubject assertThat(@NullableDecl
                                             ListMultimap<?,?> actual)

assertThat

public static SetMultimapSubject assertThat(@NullableDecl
                                            SetMultimap<?,?> actual)

assertThat

public static MultisetSubject assertThat(@NullableDecl
                                         Multiset<?> actual)

assertThat

public static TableSubject assertThat(@NullableDecl
                                      Table<?,?,?> actual)

assertThat

public static AtomicLongMapSubject assertThat(@NullableDecl
                                              AtomicLongMap<?> actual)