FEST Assertions Module has moved to Github !

Check this page :https://github.com/alexruiz/fest-assert-2.x/wiki

The documentation below is for Fest 1.x which is no more maintained, we are focusing our effort to the 2.x version !


FEST-Assert is a Java library that provides a fluent interface for writing assertions. Its main goal is to improve test code readability and make maintenance of tests easier.

FEST-Assert requires Java SE 5.0 or later and can be used with either JUnit or TestNG.

Currently, this module provides assertions for the following data types:

It can be downloaded here. For Maven 2 users, details about the project's repository can be found at here.

We have written a migration guide to easily replace JUnit assertions with Fest assertions. Note that FEST & JUnit assertions can coexist together, you don't have to migrate all in one time.


Some simple example to start.

import static org.fest.assertions.Assertions.assertThat;

int removed = employees.removeFired();

List<Employee> newEmployees = employees.hired(TODAY);
                        .contains(frodo, sam);

String[] newHires = employees.newHiresNames();
assertThat(newHires).containsOnly("Gandalf", "Arwen", "Gimli");


Custom Error Messages
Specifying custom error messages.

Extending FEST-Assert with custom conditions and assertions.

JUnit-Specific Features
FEST-Assert supports JUnit-specific features.

Comparing to Hamcrest
Comparing FEST-Assert and Hamcrest.

More Examples
Examples that how more complex usages of our assertions.

Migration from JUnit
An easy guide on how to migrate from JUnit's own assertions to ours.