Package com.google.common.truth

Class 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:

    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 (cgruber@israfil.net)

    • 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​(@Nullable 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,
                                                       @Nullable 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.

      • assertThat

        public static <ComparableT extends java.lang.Comparable<?>> ComparableSubject<ComparableT> assertThat​(@Nullable ComparableT actual)

      • assertThat

        public static BigDecimalSubject assertThat​(@Nullable java.math.BigDecimal actual)

      • assertThat

        public static Subject assertThat​(@Nullable java.lang.Object actual)

      • assertThat

        public static ThrowableSubject assertThat​(@Nullable java.lang.Throwable actual)

      • assertThat

        public static LongSubject assertThat​(@Nullable java.lang.Long actual)

      • assertThat

        public static DoubleSubject assertThat​(@Nullable java.lang.Double actual)

      • assertThat

        public static FloatSubject assertThat​(@Nullable java.lang.Float actual)

      • assertThat

        public static IntegerSubject assertThat​(@Nullable java.lang.Integer actual)

      • assertThat

        public static BooleanSubject assertThat​(@Nullable java.lang.Boolean actual)

      • assertThat

        public static StringSubject assertThat​(@Nullable java.lang.String actual)

      • assertThat

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

      • assertThat

        public static <T extends @Nullable java.lang.Object> ObjectArraySubject<T> assertThat​(T @Nullable [] actual)

      • assertThat

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

      • assertThat

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

      • assertThat

        public static OptionalSubject assertThat​(@Nullable java.util.Optional<?> actual)
        Since:
        1.3.0 (present in Truth8 since before 1.0)

      • assertThat

        public static OptionalIntSubject assertThat​(@Nullable java.util.OptionalInt actual)
        Since:
        1.3.0 (present in Truth8 since before 1.0)

      • assertThat

        public static OptionalLongSubject assertThat​(@Nullable java.util.OptionalLong actual)
        Since:
        1.4.0 (present in Truth8 since before 1.0)

      • assertThat

        public static OptionalDoubleSubject assertThat​(@Nullable java.util.OptionalDouble actual)
        Since:
        1.4.0 (present in Truth8 since before 1.0)

      • assertThat

        public static StreamSubject assertThat​(@Nullable java.util.stream.Stream<?> actual)
        Since:
        1.4.0 (present in Truth8 since before 1.0)

      • assertThat

        public static IntStreamSubject assertThat​(@Nullable java.util.stream.IntStream actual)
        Since:
        1.4.0 (present in Truth8 since before 1.0)

      • assertThat

        public static LongStreamSubject assertThat​(@Nullable java.util.stream.LongStream actual)
        Since:
        1.4.0 (present in Truth8 since before 1.0)

      • assertThat

        @GwtIncompatible
@J2ObjCIncompatible
public static PathSubject assertThat​(@Nullable java.nio.file.Path actual)
        Since:
        1.4.0 (present in Truth8 since before 1.0)