Plutus Playground Smart Contract

Playground.hs

import qualified Language.PlutusTx          as PlutusTx
import qualified Ledger.Interval            as Interval
import           Ledger.Slot                (SlotRange)
import qualified Ledger.Slot                as Slot
import           Language.PlutusTx.Prelude  as P
import           Ledger
import qualified Ledger.Ada                 as Ada
import           Ledger.Ada                 (Ada)
import           Ledger.Validation
import           Playground.Contract
import           Wallet                     as Wallet

myValidatorScript :: ValidatorScript
myValidatorScript = ValidatorScript $$(Ledger.compileScript [||
    \(ds :: ()) (rs :: ()) (_ :: PendingTx) -> ()
    ||])


helloAction :: MonadWallet m => m ()
helloAction = Wallet.logMsg "Hello World!"

$(mkFunctions ['helloAction])

Simulation.json

[0,[{"wallets":[{"simulatorWalletWallet":{"getWallet":1},"simulatorWalletBalance":{"getValue":[[{"unCurrencySymbol":""},[[{"unTokenName":""},10]]]]}},{"simulatorWalletWallet":{"getWallet":2},"simulatorWalletBalance":{"getValue":[[{"unCurrencySymbol":""},[[{"unTokenName":""},10]]]]}}],"signatures":[{"functionName":"helloAction","argumentSchema":[]},{"functionName":"payToWallet_","argumentSchema":[{"tag":"FormSchemaValue"},{"contents":[["getWallet",{"tag":"FormSchemaInt"}]],"tag":"FormSchemaObject"}]}],"currencies":[{"knownTokens":[{"unTokenName":""}],"hash":"","friendlyName":"Ada"}],"actions":[{"simulatorWallet":{"simulatorWalletWallet":{"getWallet":1},"simulatorWalletBalance":{"getValue":[[{"unCurrencySymbol":""},[[{"unTokenName":""},10]]]]}},"functionSchema":{"functionName":"helloAction","argumentSchema":[]},"tag":"Action"},{"blocks":10,"tag":"Wait"},{"simulatorWallet":{"simulatorWalletWallet":{"getWallet":2},"simulatorWalletBalance":{"getValue":[[{"unCurrencySymbol":""},[[{"unTokenName":""},10]]]]}},"functionSchema":{"functionName":"helloAction","argumentSchema":[]},"tag":"Action"},{"blocks":1,"tag":"Wait"}]}]]

Basic helloWorld