Is there infrastructure for writing unit/integration tests for our contracts, without running the full playground? Is there a test-focused EvaluatorTrace monad, for example?

2 Answers 2


There are now test capabilities in the Plutus.Contract.Test module which uses the Tasty library.

This is explained more fully in the unit tests section of lecture 8 of iteration 1 of the Plutus Pioneer Program.

Some highlights:

checkPredicate :: String -> TracePredicate -> EmulatorTrace () -> TestTree

There are a number of functions for producing a TracePredicate. For example:

-- | Check that the funds in the wallet have changed by the given amount, exluding fees.
walletFundsChange :: Wallet -> Value -> TracePredicate

Which can then be combined into a test function:

tests :: TestTree
tests = checkPredicateOptions
   (defaultCheckOptions & emulatorConfig .~ emCfg)
"token sale trace"
   ( walletFundsChange (Wallet 1) (Ada.lovelaceValueOf   10_000_000  <> assetClassValue token (-60))
.&&. walletFundsChange (Wallet 2) (Ada.lovelaceValueOf (-20_000_000) <> assetClassValue token   20)
.&&. walletFundsChange (Wallet 3) (Ada.lovelaceValueOf (- 5_000_000) <> assetClassValue token    5)

Which can then be run like this:

Prelude Spec.Trace> import Test.Tasty
Prelude Test.Tasty Spec.Trace> defaultMain tests
token sale trace: OK (1.22s)

All 1 tests passed (1.22s)

Naturally, these tests can be configured to run as part of "cabal test".


You can use Plutus Playground to test your code and maybe in the near future we will have more options.

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