Module vocabulary 

The suite’s ubiquitous language: the states the system can be in and the events that happen to it. A step only means something if it is written in these terms, which is what lets two expectations be compared mechanically.

Structs

Event

Something that happens to the system: “the user presses reset”.

EventId

VarId

Variable

A state of the system: “the kettle is off | heating | dry”.

Vocabulary

Enums

Value

A concrete value, as the system under test reports it or is driven to.

VarKind

Constants

MAX_VALUES

Most values an enumerated state can have (they’re stored as a bit set).