This software assists in preventing errors known as "Moose-stakes," allowing users to avoid mistakes that could impact their work.
The Design by Contract (DbC) approach in software programming is a way to build simple unit tests or assertions right into your regular code path. This approach guarantees the behavior and appearance of any instance of a class and is considered that class' contract. This implementation of DbC provides three types of assertions, also referred to as contract clauses, when defining a class' contract.
The first is the pre clause, which is executed before control is passed to the original method, typically used to validate incoming parameters. The second is the post clause, executed after the original method has been called, which validates return values and the state of the object following the method.
The third is the invariant clause, a special type of DbC clause that makes assertions about the ongoing state of the object. Invoked after each public method (subs that don't begin with an underscore), these clauses are only allowed to inspect the object's state, unlike post clauses.
These contract clauses are created using a declarative syntax inspired by the Moose syntax. However, it's worth noting that there's no guaranteed safe way to resume execution after a contract clause validation failure. If a method causes a clause to fail, the object in question may be irreparably broken. Catching these errors and ignoring them or trying to handle them is not advisable and makes the use of this module pointless.
If you're concerned about the end-user experience, it's best to disable all MooseX::Contract functionality in your production code and plan to have enough coverage in your development and test environments. This module should be considered experimental and should not be used in critical applications unless you're willing to deal with all the typical bugs that young, under-tested software has to offer.
In terms of its implementation, this module provides "Design by Contract" functionality using Moose method hooks. The example given shows how to use this approach in a Moose-built class, complete with pre and post contract clauses.
Overall, the Design by Contract method of programming offers a way to guarantee the behavior and appearance of any instance of a class, providing different types of contract clauses to ensure this. However, it's important to be aware of the limitations and experimental nature of this approach.
The first is the pre clause, which is executed before control is passed to the original method, typically used to validate incoming parameters. The second is the post clause, executed after the original method has been called, which validates return values and the state of the object following the method.
The third is the invariant clause, a special type of DbC clause that makes assertions about the ongoing state of the object. Invoked after each public method (subs that don't begin with an underscore), these clauses are only allowed to inspect the object's state, unlike post clauses.
These contract clauses are created using a declarative syntax inspired by the Moose syntax. However, it's worth noting that there's no guaranteed safe way to resume execution after a contract clause validation failure. If a method causes a clause to fail, the object in question may be irreparably broken. Catching these errors and ignoring them or trying to handle them is not advisable and makes the use of this module pointless.
If you're concerned about the end-user experience, it's best to disable all MooseX::Contract functionality in your production code and plan to have enough coverage in your development and test environments. This module should be considered experimental and should not be used in critical applications unless you're willing to deal with all the typical bugs that young, under-tested software has to offer.
In terms of its implementation, this module provides "Design by Contract" functionality using Moose method hooks. The example given shows how to use this approach in a Moose-built class, complete with pre and post contract clauses.
Overall, the Design by Contract method of programming offers a way to guarantee the behavior and appearance of any instance of a class, providing different types of contract clauses to ensure this. However, it's important to be aware of the limitations and experimental nature of this approach.
What's New
Version 0.01: N/A