Package com.google.common.truth

Class Truth

java.lang.Object

com.google.common.truth.Truth

public final class Truth
extends java.lang.Object

The primary entry point for Truth, a library for fluent 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).containsAtLeast(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.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	Truth.SimpleAssertionError	An AssertionError that (a) always supports a cause, even under old versions of Android and (b) omits "java.lang.AssertionError:" from the beginning of its toString() representation.

Field Summary

Fields

Modifier and Type	Field	Description
private static StandardSubjectBuilder	ASSERT
private static FailureStrategy	THROW_ASSERTION_ERROR

Constructor Summary

Constructors

Modifier	Constructor	Description
private	Truth()

Method Summary

Modifier and Type	Method	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,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 PrimitiveBooleanArraySubject	assertThat(boolean[] actual)
static PrimitiveByteArraySubject	assertThat(byte[] actual)
static PrimitiveCharArraySubject	assertThat(char[] actual)
static PrimitiveDoubleArraySubject	assertThat(double[] actual)
static PrimitiveFloatArraySubject	assertThat(float[] actual)
static PrimitiveIntArraySubject	assertThat(int[] actual)
static PrimitiveLongArraySubject	assertThat(long[] actual)
static PrimitiveShortArraySubject	assertThat(short[] actual)
static GuavaOptionalSubject	assertThat(com.google.common.base.Optional<?> actual)
static MultimapSubject	assertThat(com.google.common.collect.Multimap<?,?> actual)
static MultisetSubject	assertThat(com.google.common.collect.Multiset<?> actual)
static TableSubject	assertThat(com.google.common.collect.Table<?,?,?> actual)
static BooleanSubject	assertThat(java.lang.Boolean actual)
static ClassSubject	assertThat(java.lang.Class<?> actual)
static DoubleSubject	assertThat(java.lang.Double actual)
static FloatSubject	assertThat(java.lang.Float actual)
static IntegerSubject	assertThat(java.lang.Integer actual)
static IterableSubject	assertThat(java.lang.Iterable<?> actual)
static LongSubject	assertThat(java.lang.Long actual)
static Subject	assertThat(java.lang.Object actual)
static StringSubject	assertThat(java.lang.String actual)
static ThrowableSubject	assertThat(java.lang.Throwable actual)
static BigDecimalSubject	assertThat(java.math.BigDecimal actual)
static MapSubject	assertThat(java.util.Map<?,?> actual)
static <T extends java.lang.Comparable<?>> ComparableSubject<T>	assertThat(T actual)
static <T> ObjectArraySubject<T>	assertThat(T[] actual)
static StandardSubjectBuilder	assertWithMessage(java.lang.String messageToPrepend)	Begins an assertion that, if it fails, will prepend the given message to the failure message.
static StandardSubjectBuilder	assertWithMessage(java.lang.String format, java.lang.Object... args)	Begins an assertion that, if it fails, will prepend the given message to the failure message.

Methods inherited from class java.lang.Object

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

Field Detail

THROW_ASSERTION_ERROR

private static final FailureStrategy THROW_ASSERTION_ERROR

ASSERT

private static final StandardSubjectBuilder ASSERT

Constructor Detail

Truth

private Truth()

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(java.lang.String messageToPrepend)

Begins an assertion that, if it fails, will prepend the given message to the failure message.

This method is a shortcut for assert_().withMessage(...).

To set a message when using a custom subject, use assertWithMessage(...).about(...), as discussed in this FAQ entry.

assertWithMessage

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

Begins an assertion that, if it fails, will prepend the given message to the failure message.

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

This method is a shortcut for assert_().withMessage(...).

To set a message when using a custom subject, use assertWithMessage(...).about(...), as discussed in this FAQ entry.

Throws:

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

assertAbout

public static <S extends Subject,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 java.lang.Comparable<?>> ComparableSubject<T> assertThat(T actual)

assertThat

public static BigDecimalSubject assertThat(java.math.BigDecimal actual)

assertThat

public static Subject assertThat(java.lang.Object actual)

assertThat

public static ClassSubject assertThat(java.lang.Class<?> actual)

assertThat

public static ThrowableSubject assertThat(java.lang.Throwable actual)

assertThat

public static LongSubject assertThat(java.lang.Long actual)

assertThat

public static DoubleSubject assertThat(java.lang.Double actual)

assertThat

public static FloatSubject assertThat(java.lang.Float actual)

assertThat

public static IntegerSubject assertThat(java.lang.Integer actual)

assertThat

public static BooleanSubject assertThat(java.lang.Boolean actual)

assertThat

public static StringSubject assertThat(java.lang.String actual)

assertThat

public static IterableSubject assertThat(java.lang.Iterable<?> actual)

assertThat

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

assertThat

public static PrimitiveBooleanArraySubject assertThat(boolean[] actual)

assertThat

public static PrimitiveShortArraySubject assertThat(short[] actual)

assertThat

public static PrimitiveIntArraySubject assertThat(int[] actual)

assertThat

public static PrimitiveLongArraySubject assertThat(long[] actual)

assertThat

public static PrimitiveByteArraySubject assertThat(byte[] actual)

assertThat

public static PrimitiveCharArraySubject assertThat(char[] actual)

assertThat

public static PrimitiveFloatArraySubject assertThat(float[] actual)

assertThat

public static PrimitiveDoubleArraySubject assertThat(double[] actual)

assertThat

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

assertThat

public static MapSubject assertThat(java.util.Map<?,?> actual)

assertThat

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

assertThat

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

assertThat

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