GCONTRACTS is a Groovy framework that supports design by contract modeling through annotations like @Ensures, @Requires and @Invariant to specify preconditions, postconditions and class invariants. It helps implement a "contract first" design approach and specify the rules and agreements of software, making behaviors explicit and able to be integrated into interfaces and inherited classes, although it is currently a beta project with some unfinished features.

1. GCONTRACTS

2. What Is It?
 Groovy Framwork to support design by
contract modeling

3. Design By Contract?

4. It’s About Software Agreements

5. Pre, Post Conditions and
Invariants

6. It Isn't Strictly for SOA

7. @Ensures and @Requires

8. @Invariant

9. Usable in Interfaces

10. Inheritance Support

11. Why Need I Use It?
 Helpful in a “Contract first”
Design apporach

12. Why Need I Use It?
 You should
specify the rules

13. Why Need I Use It?
 Can be pretty well
integrated

14. Contras
 It’s a beta project
 Some features are still in development