Assertion Settings

Author: Matthias Konrad

Motivation

The Eiffel Language specifies several assertion types:

• Preconditions
• Postconditions
• Invariants
• Loop variants
• Checks

In theory these assertions should be checked all the time. In practice, especially when working with huge systems, this is not possible. In some cases it is not even possible during the testing phase of the system. It is thus nessecary to decide which assertions should be tested. This decicion can be done by either the user or the compiler.</p>

It is not enough to just enable or disable a certain assertion kind for the hole system. Large systems are composed of smaller parts and reused components. These are typically tested independently (unit level testing). It is thus important that assertions are checked on the untested part of the system and for performance reasons not tested on the allready tested parts.

In EiffelStudio the user has to make this desicion. let the user define whether assertions are checked on various levels:

• Class
• Cluster
• Library
• System