package ortac-runtime-qcheck-stm
Library
Module
Module type
Parameter
Class
Class type
val arb_cmd : state -> cmd QCheck.arbitrary
A command generator. Accepts a state parameter to enable state-dependent cmd
generation.
val init_state : state
The model's initial state.
val show_cmd : cmd -> string
show_cmd c
returns a string representing the command c
.
next_state c s
expresses how interpreting the command c
moves the model's internal state machine from the state s
to the next state. Ideally a next_state
function is pure, as it is run more than once.
val init_sut : unit -> sut
Initialize the system under test.
val cleanup : sut -> unit
Utility function to clean up the sut
after each test instance, e.g., for closing sockets, files, or resetting global parameters
precond c s
expresses preconditions for command c
in terms of the model state s
. A precond
function should be pure. precond
is useful, e.g., to prevent the shrinker from breaking invariants when minimizing counterexamples.
run c i
should interpret the command c
over the system under test (typically side-effecting).
postcond c s res
checks whether res
arising from interpreting the command c
over the system under test with run
agrees with the model's result. A postcond
function should be a pure.
Note: the state parameter s
is the model's state
before executing the command c
(the "old/pre" state). This is helpful to model, e.g., a remove
cmd
that returns the removed element.