week03

Testing with Emulator

Write tests

• See ./test/Homework1.hs for how to write tests with the Emulator

• In principle

  • Define what the expected change in the wallet is (predicate). Like: 100 more ADA.
  • Write the flow of actions similar to how it is done in playground. With the following primitives:
    • Calling contract endpoints and
    • "Waiting until" or "for" an amount of slots (between contract actions)
  • Run tests it with cabal test

• Example snipped (see test/Homework1 for how to embed the following code properly in your test suite):

let giveAway :: Integer
    giveAway = 100
    deadline :: Slot
    deadline = 20
 in checkPredicate
      "grabber can get back money before deadline"
      ( walletFundsChange w1 (Ada.lovelaceValueOf (- giveAway))
          .&&. walletFundsChange w2 (Ada.lovelaceValueOf giveAway)
          .&&. assertNoFailedTransactions
      )
      $ do
        _ <- callGive w1 w2 deadline giveAway
        void $ Trace.waitUntilSlot (deadline - 1)
        callGrab w2
        void $ Trace.waitNSlots 1,

Interactive testing in repl

• Launch repl with test-suite

cabal repl plutus-pioneer-program-week03-test

• Import EmulatorRenderer and test cases, like Homework1

import EmulatorRenderer
import Homework1

• Run test case testCaseLecture (is of type EmulatorTrace ()) with logging

printEmulatorLog testCaseLecture

References

• Crowdfunding source code and tests in plutus-use-cases