2 Why We Need Model-Based Testing

290 Modeling Library Reference
If the target of an [AcceptingStateCondition] attribute is a method, it is possible
for the method to be a static method or an instance method. In the case of an instance
method, the state is accepting if the condition holds for all reachable instances of
the class. The return type must be System.Boolean.
A.1.7 State invariants
It is possible to indicate conditions called state invariants that must hold in every
state. The failure of any state invariant indicates a modeling error.
The [StateInvariant] attribute indicates that the target method, field, or property
must hold in every state.
An example of the use of this attribute is
namespace MyModelProgram
{
static class Contract
{
static Set pendingRequests = Set.EmptySet;
static int nPendingRequests = 0;
}
}
[StateInvariant]
static bool IsConsisitent()
{
return pendingRequests.Count == nPendingRequests;
}
If the target of an [StateInvariant] attribute is a method, it is possible for the
method to be a static method or an instance method. In the case of an instance
method, the state invariant is said to hold if the return value is true for all reachable
instances of the class. The return type must be System.Boolean.
A.1.8 State filters
A state filter is a Boolean condition that indicates that a state, although valid, should
be excluded from exploration. The [StateFilter] attribute indicates that its target
method, property, or field is a state filter. A value of true indicates that the state will
be included; false means exclusion from exploration.
namespace MyModelProgram
{
static class Contract
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