States
States are used to specify that invocations can occur only during some state that is initiated and/or terminated by other expected invocations. A test can define multiple state machines and an invocation can be constrained to occur during a state of one more more state machines.
To define a new state machine:
Raw
final States state-machine-name = context.states("state-machine-name").startsAs("initial-state");
JUnit 3
final States state-machine-name = states("state-machine-name").startsAs("initial-state");
JUnit 4
final States state-machine-name = context.states("state-machine-name").startsAs("initial-state");
The intial state is optional. If not specified, the state machine starts in an unnamed initial state.
The following clauses constrain invocations to occur within specific states and define how an invocation will change the current state of a state machine.
| when(state-machine.is("state-name")); | Constrains the last expectation to occur only when the state machine is in the named state. |
| when(state-machine.isNot("state-name")); | Constrains the last expectation to occur only when the state machine is not in the named state. |
| then(state-machine.is("state-name")); | Changes the state of state-machine to the named state when the invocation occurs. |
For example:
final States pen = context.states("pen").startsAs("up");
oneOf (turtle).penDown(); then(pen.is("down"));
oneOf (turtle).forward(10); when(pen.is("down"));
oneOf (turtle).turn(90); when(pen.is("down"));
oneOf (turtle).forward(10); when(pen.is("down"));
oneOf (turtle).penUp(); then(pen.is("up"));