{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE PolyKinds #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE ScopedTypeVariables #-}
-----------------------------------------------------------------------------
-- |
-- Module : Test.StateMachine.Sequential
-- Copyright : (C) 2017, ATS Advanced Telematic Systems GmbH
-- License : BSD-style (see the file LICENSE)
--
-- Maintainer : Stevan Andjelkovic <stevan.andjelkovic@here.com>
-- Stability : provisional
-- Portability : non-portable (GHC extensions)
--
-- This module contains helpers for generating, shrinking, and checking
-- sequential programs.
--
-----------------------------------------------------------------------------
module Test.StateMachine.Sequential
( forAllCommands
, generateCommands
, generateCommandsState
, measureFrequency
, calculateFrequency
, getUsedVars
, shrinkCommands
, liftShrinkCommand
, validCommands
, filterMaybe
, runCommands
, getChanContents
, executeCommands
, prettyPrintHistory
, prettyCommands
, commandNames
, commandNamesInOrder
, checkCommandNames
, transitionMatrix
)
where
import Control.Exception
(ErrorCall, IOException, displayException)
import Control.Monad.Catch
(MonadCatch, catch)
import Control.Monad.State
(State, StateT, evalState, evalStateT, get, lift, put,
runStateT)
import Data.Dynamic
(Dynamic, toDyn)
import Data.Either
(fromRight)
import Data.List
(elemIndex)
import qualified Data.Map as M
import Data.Map.Strict
(Map)
import Data.Matrix
(Matrix, getRow, matrix)
import Data.Maybe
(fromMaybe)
import Data.Monoid
((<>))
import Data.Proxy
(Proxy(..))
import qualified Data.Set as S
import Data.TreeDiff
(ToExpr, ansiWlBgEditExprCompact, ediff)
import qualified Data.Vector as V
import GHC.Generics
(Generic1, Rep1, from1)
import Prelude
import Test.QuickCheck
(Gen, Property, Testable, choose, collect, generate,
resize, shrinkList, sized, suchThat)
import Test.QuickCheck.Monadic
(PropertyM, run)
import Text.PrettyPrint.ANSI.Leijen
(Doc)
import qualified Text.PrettyPrint.ANSI.Leijen as PP
import Text.Show.Pretty
(ppShow)
import UnliftIO
(MonadIO, TChan, newTChanIO, tryReadTChan, writeTChan,
atomically)
import Test.StateMachine.ConstructorName
import Test.StateMachine.Logic
import Test.StateMachine.Types
import qualified Test.StateMachine.Types.Rank2 as Rank2
import Test.StateMachine.Utils
------------------------------------------------------------------------
forAllCommands :: Testable prop
=> (Show (cmd Symbolic), Show (model Symbolic))
=> (Generic1 cmd, GConName1 (Rep1 cmd))
=> (Rank2.Traversable cmd, Rank2.Foldable resp)
=> StateMachine model cmd m resp
-> Maybe Int -- ^ Minimum number of commands.
-> (Commands cmd -> prop) -- ^ Predicate.
-> Property
forAllCommands sm mnum =
forAllShrinkShow (generateCommands sm mnum) (shrinkCommands sm) ppShow
generateCommands :: (Rank2.Foldable resp, Show (model Symbolic))
=> (Generic1 cmd, GConName1 (Rep1 cmd))
=> StateMachine model cmd m resp
-> Maybe Int -- ^ Minimum number of commands.
-> Gen (Commands cmd)
generateCommands sm@StateMachine { initModel } mnum =
evalStateT (generateCommandsState sm newCounter mnum) (initModel, Nothing)
generateCommandsState :: forall model cmd m resp. Rank2.Foldable resp
=> Show (model Symbolic)
=> (Generic1 cmd, GConName1 (Rep1 cmd))
=> StateMachine model cmd m resp
-> Counter
-> Maybe Int -- ^ Minimum number of commands.
-> StateT (model Symbolic, Maybe (cmd Symbolic)) Gen (Commands cmd)
generateCommandsState StateMachine { precondition, generator, transition
, mock, distribution } counter0 mnum = do
size0 <- lift (sized (\k -> choose (fromMaybe 0 mnum, k)))
Commands <$> go size0 counter0 []
where
go :: Int -> Counter -> [Command cmd]
-> StateT (model Symbolic, Maybe (cmd Symbolic)) Gen [Command cmd]
go 0 _ cmds = return (reverse cmds)
go size counter cmds = do
(model, mprevious) <- get
case generator model of
Nothing -> return (reverse cmds)
Just cmd -> do
mnext <- lift $ commandFrequency cmd distribution mprevious
`suchThatOneOf` (boolean . precondition model)
case mnext of
Nothing -> error $ concat
[ "A deadlock occured while generating commands.\n"
, "No pre-condition holds in the following model:\n"
, ppShow model
-- XXX: show trace of commands generated so far?
]
Just next -> do
let (resp, counter') = runGenSym (mock model next) counter
put (transition model next resp, Just next)
go (size - 1) counter' (Command next (getUsedVars resp) : cmds)
commandFrequency :: forall cmd. (Generic1 cmd, GConName1 (Rep1 cmd))
=> Gen (cmd Symbolic) -> Maybe (Matrix Int) -> Maybe (cmd Symbolic)
-> [(Int, Gen (cmd Symbolic))]
commandFrequency gen Nothing _ = [ (1, gen) ]
commandFrequency gen (Just distribution) mprevious =
[ (freq, gen `suchThat` ((== con) . gconName1 . from1)) | (freq, con) <- weights ]
where
idx = case mprevious of
Nothing -> 1
Just previous ->
let
rep = from1 previous
con = gconName1 rep
err = "genetateCommandState: no command: " <> con
in
fromMaybe (error err) ((+ 2) <$>
elemIndex con (gconNames1 (Proxy :: Proxy (Rep1 cmd Symbolic))))
row = V.toList (getRow idx distribution)
weights = zip row (gconNames1 (Proxy :: Proxy (Rep1 cmd Symbolic)))
measureFrequency :: (Rank2.Foldable resp, Show (model Symbolic))
=> (Generic1 cmd, GConName1 (Rep1 cmd))
=> StateMachine model cmd m resp
-> Maybe Int -- ^ Minimum number of commands.
-> Int -- ^ Maximum number of commands.
-> IO (Map (String, Maybe String) Int)
measureFrequency sm min0 size = do
cmds <- generate (sequence [ resize n (generateCommands sm min0) | n <- [0, 2..size] ])
return (M.unions (map calculateFrequency cmds))
calculateFrequency :: (Generic1 cmd, GConName1 (Rep1 cmd))
=> Commands cmd -> Map (String, Maybe String) Int
calculateFrequency = go M.empty . unCommands
where
go m [] = m
go m [cmd]
= M.insertWith (\_ old -> old + 1) (gconName cmd, Nothing) 1 m
go m (cmd1 : cmd2 : cmds)
= go (M.insertWith (\_ old -> old + 1) (gconName cmd1,
Just (gconName cmd2)) 1 m) cmds
getUsedVars :: Rank2.Foldable f => f Symbolic -> [Var]
getUsedVars = Rank2.foldMap (\(Symbolic v) -> [v])
-- | Shrink commands in a pre-condition and scope respecting way.
shrinkCommands :: (Rank2.Traversable cmd, Rank2.Foldable resp)
=> StateMachine model cmd m resp -> Commands cmd
-> [Commands cmd]
shrinkCommands sm@StateMachine { initModel, shrinker }
= filterMaybe ( flip evalState (initModel, M.empty, newCounter)
. validCommands sm
. Commands)
. shrinkList (liftShrinkCommand shrinker)
. unCommands
liftShrinkCommand :: (cmd Symbolic -> [cmd Symbolic])
-> (Command cmd -> [Command cmd])
liftShrinkCommand shrinker (Command cmd resp) =
[ Command cmd' resp | cmd' <- shrinker cmd ]
filterMaybe :: (a -> Maybe b) -> [a] -> [b]
filterMaybe _ [] = []
filterMaybe f (x : xs) = case f x of
Nothing -> filterMaybe f xs
Just y -> y : filterMaybe f xs
validCommands :: forall model cmd m resp. (Rank2.Traversable cmd, Rank2.Foldable resp)
=> StateMachine model cmd m resp -> Commands cmd
-> State (model Symbolic, Map Var Var, Counter) (Maybe (Commands cmd))
validCommands StateMachine { precondition, transition, mock } =
fmap (fmap Commands) . go . unCommands
where
-- As we validate we keep track of the variables that are in scope, in terms
-- of a mapping from old variables to new variables. For example, if a
-- command previously returned variables @[x',y']@, and in the new model
-- returns @[x,y]@, we extend our scope mapping with @[(x',x),(y',y)]@.
-- Later commands will then be translated accordingly, replacing references
-- to @x'@ by references to @y'@; references for which we have no updated
-- variable in scope are considered invalid: this may happen if those later
-- commands refer to a command which shrinking deleted altogether, /or/ it
-- may happen when the command was not deleted but in the new model returned
-- fewer references.
go :: [Command cmd] -> State (model Symbolic, Map Var Var, Counter) (Maybe [Command cmd])
go [] = return (Just [])
go (Command cmd' vars' : cmds) = do
(model, scope, counter) <- get
case Rank2.traverse (remapVars scope) cmd' of
Just cmd | boolean (precondition model cmd) -> do
let (resp, counter') = runGenSym (mock model cmd) counter
vars = getUsedVars resp
put ( transition model cmd resp
, M.fromList (zip vars' vars) `M.union` scope
, counter')
mih <- go cmds
case mih of
Nothing -> return Nothing
Just ih -> return (Just (Command cmd vars : ih))
_otherwise ->
return Nothing
remapVars :: Map Var Var -> Symbolic a -> Maybe (Symbolic a)
remapVars scope (Symbolic v) = Symbolic <$> M.lookup v scope
runCommands :: (Rank2.Traversable cmd, Rank2.Foldable resp)
=> (MonadCatch m, MonadIO m)
=> StateMachine model cmd m resp
-> Commands cmd
-> PropertyM m (History cmd resp, model Concrete, Reason)
runCommands sm@StateMachine { initModel } = run . go
where
go cmds = do
hchan <- newTChanIO
(reason, (_, _, _, model)) <- runStateT
(executeCommands sm hchan (Pid 0) True cmds)
(emptyEnvironment, initModel, newCounter, initModel)
hist <- getChanContents hchan
return (History hist, model, reason)
getChanContents :: MonadIO m => TChan a -> m [a]
getChanContents chan = reverse <$> atomically (go' [])
where
go' acc = do
mx <- tryReadTChan chan
case mx of
Just x -> go' (x : acc)
Nothing -> return acc
executeCommands :: (Rank2.Traversable cmd, Rank2.Foldable resp)
=> (MonadCatch m, MonadIO m)
=> StateMachine model cmd m resp
-> TChan (Pid, HistoryEvent cmd resp)
-> Pid
-> Bool -- ^ Check invariant and post-condition?
-> Commands cmd
-> StateT (Environment, model Symbolic, Counter, model Concrete) m Reason
executeCommands StateMachine {..} hchan pid check =
go . unCommands
where
go [] = return Ok
go (Command scmd vars : cmds) = do
(env, smodel, counter, cmodel) <- get
case (check, logic (precondition smodel scmd)) of
(True, VFalse ce) -> return (PreconditionFailed (show ce))
_ -> do
let ccmd = fromRight (error "executeCommands: impossible") (reify env scmd)
atomically (writeTChan hchan (pid, Invocation ccmd (S.fromList vars)))
!ecresp <- lift (fmap Right (semantics ccmd))
`catch` (\(err :: IOException) ->
return (Left (displayException err)))
`catch` (\(err :: ErrorCall) ->
return (Left (displayException err)))
case ecresp of
Left err -> do
atomically (writeTChan hchan (pid, Exception err))
return ExceptionThrown
Right cresp -> do
atomically (writeTChan hchan (pid, Response cresp))
let (sresp, counter') = runGenSym (mock smodel scmd) counter
case (check, logic (postcondition cmodel ccmd cresp)) of
(True, VFalse ce) -> return (PostconditionFailed (show ce))
_ -> case (check, logic (fromMaybe (const Top) invariant cmodel)) of
(True, VFalse ce') -> return (InvariantBroken (show ce'))
_ -> do
put ( insertConcretes vars (getUsedConcrete cresp) env
, transition smodel scmd sresp
, counter'
, transition cmodel ccmd cresp
)
go cmds
getUsedConcrete :: Rank2.Foldable f => f Concrete -> [Dynamic]
getUsedConcrete = Rank2.foldMap (\(Concrete x) -> [toDyn x])
modelDiff :: ToExpr (model r) => model r -> Maybe (model r) -> Doc
modelDiff model = ansiWlBgEditExprCompact . flip ediff model . fromMaybe model
prettyPrintHistory :: forall model cmd m resp. ToExpr (model Concrete)
=> (Show (cmd Concrete), Show (resp Concrete))
=> StateMachine model cmd m resp
-> History cmd resp
-> IO ()
prettyPrintHistory StateMachine { initModel, transition }
= PP.putDoc
. go initModel Nothing
. makeOperations
. unHistory
where
go :: model Concrete -> Maybe (model Concrete) -> [Operation cmd resp] -> Doc
go current previous [] =
PP.line <> modelDiff current previous <> PP.line <> PP.line
go current previous [Crash cmd err pid] =
mconcat
[ PP.line
, modelDiff current previous
, PP.line, PP.line
, PP.string " == "
, PP.string (show cmd)
, PP.string " ==> "
, PP.string err
, PP.string " [ "
, PP.int (unPid pid)
, PP.string " ]"
, PP.line
]
go current previous (Operation cmd resp pid : ops) =
mconcat
[ PP.line
, modelDiff current previous
, PP.line, PP.line
, PP.string " == "
, PP.string (show cmd)
, PP.string " ==> "
, PP.string (show resp)
, PP.string " [ "
, PP.int (unPid pid)
, PP.string " ]"
, PP.line
, go (transition current cmd resp) (Just current) ops
]
go _ _ _ = error "prettyPrintHistory: impossible."
prettyCommands :: (MonadIO m, ToExpr (model Concrete))
=> (Show (cmd Concrete), Show (resp Concrete))
=> StateMachine model cmd m resp
-> History cmd resp
-> Property
-> PropertyM m ()
prettyCommands sm hist prop = prettyPrintHistory sm hist `whenFailM` prop
------------------------------------------------------------------------
-- | Print distribution of commands and fail if some commands have not
-- been executed.
checkCommandNames :: forall cmd. (Generic1 cmd, GConName1 (Rep1 cmd))
=> Commands cmd -> Property -> Property
checkCommandNames cmds
= collect names
. oldCover (length names == numOfConstructors) 1 "coverage"
where
names = commandNames cmds
numOfConstructors = length (gconNames1 (Proxy :: Proxy (Rep1 cmd Symbolic)))
commandNames :: forall cmd. (Generic1 cmd, GConName1 (Rep1 cmd))
=> Commands cmd -> [(String, Int)]
commandNames = M.toList . foldl go M.empty . unCommands
where
go :: Map String Int -> Command cmd -> Map String Int
go ih cmd = M.insertWith (+) (gconName cmd) 1 ih
commandNamesInOrder :: forall cmd. (Generic1 cmd, GConName1 (Rep1 cmd))
=> Commands cmd -> [String]
commandNamesInOrder = reverse . foldl go [] . unCommands
where
go :: [String] -> Command cmd -> [String]
go ih cmd = gconName cmd : ih
transitionMatrix :: forall cmd. GConName1 (Rep1 cmd)
=> Proxy (cmd Symbolic)
-> (String -> String -> Int) -> Matrix Int
transitionMatrix _ f =
let cons = gconNames1 (Proxy :: Proxy (Rep1 cmd Symbolic))
n = length cons
m = succ n
in matrix m n $ \case
(1, j) -> f "<START>" (cons !! pred j)
(i, j) -> f (cons !! pred (pred i)) (cons !! pred j)