Truth is a library for performing assertions in tests:

assertThat(notificationText).contains("testuser@google.com");

Truth is owned and maintained by the Guava team. It is used in the majority of the tests in Google’s own codebase.

For more information, see our introduction and other docs.

Packages 
Package Description
com.google.common.truth
Truth is a library for performing assertions in tests:
com.google.common.truth.extensions.proto
Custom subjects for testing Protocol Buffer instances.
com.google.common.truth.extensions.re2j