Merge pull request #27 from geniusyield/11-wrong-strategy-value-stran…

…ge-error

11 wrong strategy value strange error

README.md

@@ -444,9 +444,12 @@ oneBuyToManySell :: Natural -> OrderBook -> [MatchResult]
 oneBuyToManySell _ _ = []
 ```
 
-Even more! We can go to the [Main](./geniusyield-orderbot/test/Main.hs) testing module,
-and add the new constructor `OneBuyToManySell` to ["Strategies tests" list](./geniusyield-orderbot/test/Main.hs#L25C9-L25C29)
-and it will be enough to start testing our strategy by running the tests.
+Even more! We can add the new constructor `OneBuyToManySell` to the `allStrategies` list and it will be enough to start testing our strategy by running the tests.
+
+```haskell
+allStrategies :: [BotStrategy]
+allStrategies = [OneSellToManyBuy]
+```
 
 Finishing the implementation of `oneBuyToManySell` is left as an exercise.
 

geniusyield-orderbot/src/OrderBotConfig.hs

@@ -11,6 +11,7 @@ module OrderBotConfig where
 import           Control.Exception ( throwIO )
 import           Control.Monad ( (<=<) )
 import           Control.Monad.Reader ( runReaderT )
+import           Control.Monad.Error.Class ( throwError )
 import           Data.Aeson ( eitherDecodeFileStrict
                             , (.:), (.:?)
                             , withArray, withObject
@@ -26,7 +27,9 @@ import qualified Data.Vector as V
 import           Data.List ( nub )
 import           GHC.Generics ( Generic )
 import           GHC.Natural ( naturalToInteger )
-import           System.Envy ( FromEnv (fromEnv), envMaybe, env, decodeEnv )
+import           System.Envy ( FromEnv (fromEnv), Var, Parser, envMaybe, env
+                             , decodeEnv
+                             )
 import           System.Random.MWC (fromSeed, initialize, createSystemSeed)
 
 import           Ply (readTypedScript, TypedScript, ScriptRole (..))
@@ -44,7 +47,7 @@ import           Cardano.Api ( AsType (AsSigningKey, AsPaymentKey)
                              , deserialiseFromTextEnvelope
                              )
 
-import           Strategies ( BotStrategy(..), mkIndependentStrategy )
+import           Strategies ( BotStrategy(..), allStrategies, mkIndependentStrategy )
 import           GeniusYield.DEX.Api.Types
 
 -- | Order bot vanilla config.
@@ -97,30 +100,37 @@ instance FromEnv OrderBotConfig where
         OrderBotConfig
         <$> (Right . parseCBORSKey <$> env "BOTC_SKEY")
         <*> (fmap fromString <$> envMaybe "BOTC_COLLATERAL")
-        <*> env "BOTC_EXECUTION_STRAT"
+        <*> envWithMsg ("Invalid Strategy. Must be one of: " ++ show allStrategies) "BOTC_EXECUTION_STRAT"
         <*> (parseArray <$> env "BOTC_ASSET_FILTER")
-        <*> env "BOTC_RESCAN_DELAY"
+        <*> envIntWithMsg "BOTC_RESCAN_DELAY"
         <*> env "BOTC_FP_NFT_POLICY"
         <*> env "BOTC_FP_ORDER_VALIDATOR"
-        <*> env "BOTC_MAX_ORDERS_MATCHES"
-        <*> env "BOTC_MAX_TXS_PER_ITERATION"
-        <*> env "BOTC_RANDOMIZE_MATCHES_FOUND"
+        <*> envIntWithMsg "BOTC_MAX_ORDERS_MATCHES"
+        <*> envIntWithMsg "BOTC_MAX_TXS_PER_ITERATION"
+        <*> envWithMsg "Must be either 'True' or 'False'" "BOTC_RANDOMIZE_MATCHES_FOUND"
         <*> (parsePORDict <$> env "BOTC_POREFS")
       where
         parseCBORSKey :: String -> GYPaymentSigningKey
         parseCBORSKey s =
-            either error paymentSigningKeyFromApi $
+            either (error . ("Error parsing 'BOTC_SKEY': " ++)) paymentSigningKeyFromApi $
             eitherDecodeStrict (fromString s) >>=
             first show . deserialiseFromTextEnvelope (AsSigningKey AsPaymentKey)
 
         parsePORDict :: String -> PORConfig
-        parsePORDict = either error id . eitherDecodeStrict . fromString
+        parsePORDict = either (error . ("Error parsing 'BOTC_POREFS': " ++)) id
+                        . eitherDecodeStrict . fromString
 
         parseArray :: String -> [OrderAssetPair]
-        parseArray s = either error id $
+        parseArray s = either (error . ("Error parsing 'BOTC_ASSET_FILTER': " ++) ) id $
             eitherDecodeStrict (fromString s) >>=
             Aeson.parseEither parseScanTokenPairs
 
+envIntWithMsg :: Var a => String -> Parser a
+envIntWithMsg = envWithMsg "Not a number"
+
+envWithMsg :: Var a => String -> String -> Parser a
+envWithMsg msg name = maybe (throwError $ unwords ["Error parsing enviroment variable", name ++ ":", msg]) return =<< envMaybe name
+
 instance FromJSON OrderBotConfig where
     parseJSON (Object obj) = OrderBotConfig
         <$> (Left <$> obj .: "signingKeyFP")

geniusyield-orderbot/src/Strategies.hs

@@ -8,6 +8,7 @@ Stability   : develop
 -}
 module Strategies
     ( BotStrategy(..)
+    , allStrategies
     , mkIndependentStrategy
     ) where
 
@@ -50,6 +51,12 @@ instance Var BotStrategy where
         _                  -> Nothing
     toVar = show
 
+{- | A list containing all implemented strategies. This list is used for the
+     tests and for the error message during env variable parsing.
+-}
+allStrategies :: [BotStrategy]
+allStrategies = [OneSellToManyBuy]
+
 {- | Given a bot strategy and a max amount of orders per transaction, creates
      an independent strategy.
 -}

geniusyield-orderbot/test/Main.hs

@@ -18,11 +18,7 @@ main =  defaultMain $ testGroup "QC"
         , testProperty "sellsAreInOrder" propSellsAreInOrder
         , testProperty "buysAreInOrder" propBuysAreInOrder
         ]
-    , testGroup "Strategies tests" $ map qcTestsForStrategy
-        -- Every strategy property is ran over each element of this list. So adding
-        -- a new BotStrategy constructor to the list is enough to include the new
-        -- strategy into the complete tests suit.
-        [ OneSellToManyBuy ]
+    , testGroup "Strategies tests" $ map qcTestsForStrategy allStrategies
     ]
 
 qcTestsForStrategy :: BotStrategy -> TestTree