corda/tests/CashTests.kt

import org.junit.Test

// TODO: Some basic invariants should be enforced by the platform before contract execution:
// 1. No duplicate input states
// 2. There must be at least one input state (note: not "one of the type the contract wants")


class CashTests {
    val inState = CashState(
            issuingInstitution = MEGA_CORP,
            depositReference = byteArrayOf(1),
            amount = 1000.DOLLARS,
            owner = DUMMY_PUBKEY_1
    )
    val outState = inState.copy(owner = DUMMY_PUBKEY_2)
    
    val contract = CashContract()

    @Test
    fun trivial() {
        transaction {
            contract `fails requirement` "there is at least one cash input"

            input { inState }
            contract `fails requirement` "the amounts balance"

            transaction {
                output { outState.copy(amount = 2000.DOLLARS )}
                contract `fails requirement` "the amounts balance"
            }
            transaction {
                output { outState }
                // No command arguments
                contract `fails requirement` "the owning keys are the same as the signing keys"
            }
            transaction {
                output { outState }
                arg(DUMMY_PUBKEY_2) { MoveCashCommand() }
                contract `fails requirement` "the owning keys are the same as the signing keys"
            }
            transaction {
                output { outState }
                output { outState.copy(issuingInstitution = MINI_CORP) }
                contract `fails requirement` "no output states are unaccounted for"
            }
            // Simple reallocation works.
            transaction {
                output { outState }
                arg(DUMMY_PUBKEY_1) { MoveCashCommand() }
                contract.accepts()
            }
        }
    }

    @Test
    fun testMergeSplit() {
        // Splitting value works.
        transaction {
            arg(DUMMY_PUBKEY_1) { MoveCashCommand() }
            transaction {
                input { inState }
                for (i in 1..4) output { inState.copy(amount = inState.amount / 4) }
                contract.accepts()
            }
            // Merging 4 inputs into 2 outputs works.
            transaction {
                for (i in 1..4) input { inState.copy(amount = inState.amount / 4) }
                output { inState.copy(amount = inState.amount / 2) }
                output { inState.copy(amount = inState.amount / 2) }
                contract.accepts()
            }
            // Merging 2 inputs into 1 works.
            transaction {
                input { inState.copy(amount = inState.amount / 2) }
                input { inState.copy(amount = inState.amount / 2) }
                output { inState }
                contract.accepts()
            }
        }

    }

    @Test
    fun zeroSizedInputs() {
        transaction {
            input { inState }
            input { inState.copy(amount = 0.DOLLARS) }
            contract `fails requirement` "zero sized inputs"
        }
    }

    @Test
    fun trivialMismatches() {
        // Can't change issuer.
        transaction {
            input { inState }
            output { outState.copy(issuingInstitution = MINI_CORP) }
            contract `fails requirement` "for issuer MegaCorp the amounts balance"
        }
        // Can't change deposit reference when splitting.
        transaction {
            input { inState }
            output { outState.copy(depositReference = byteArrayOf(0), amount = inState.amount / 2) }
            output { outState.copy(depositReference = byteArrayOf(1), amount = inState.amount / 2) }
            contract `fails requirement` "the deposit references are the same"
        }
        // Can't mix currencies.
        transaction {
            input { inState }
            output { outState.copy(amount = 800.DOLLARS) }
            output { outState.copy(amount = 200.POUNDS) }
            contract `fails requirement` "all outputs use the currency of the inputs"
        }
        transaction {
            input { inState }
            input {
                inState.copy(
                    amount = 150.POUNDS,
                    owner = DUMMY_PUBKEY_2
                )
            }
            output { outState.copy(amount = 1150.DOLLARS) }
            contract `fails requirement` "all inputs use the same currency"
        }
        transaction {
            input { inState }
            input { inState.copy(issuingInstitution = MINI_CORP) }
            output { outState }
            contract `fails requirement` "for issuer MiniCorp the amounts balance"
        }
    }

    @Test
    fun exitLedger() {
        // Single input/output straightforward case.
        transaction {
            input { inState }
            output { outState.copy(amount = inState.amount - 200.DOLLARS) }

            transaction {
                arg(MEGA_CORP_KEY) { ExitCashCommand(100.DOLLARS) }
                contract `fails requirement` "the amounts balance"
            }

            transaction {
                arg(MEGA_CORP_KEY) { ExitCashCommand(200.DOLLARS) }
                contract `fails requirement` "the owning keys are the same as the signing keys"   // No move command.

                transaction {
                    arg(DUMMY_PUBKEY_1) { MoveCashCommand() }
                    contract.accepts()
                }
            }
        }
        // Multi-issuer case.
        transaction {
            input { inState }
            input { inState.copy(issuingInstitution = MINI_CORP) }

            output { inState.copy(issuingInstitution = MINI_CORP, amount = inState.amount - 200.DOLLARS) }
            output { inState.copy(amount = inState.amount - 200.DOLLARS) }

            arg(DUMMY_PUBKEY_1) { MoveCashCommand() }

            contract `fails requirement` "for issuer MegaCorp the amounts balance"

            arg(MEGA_CORP_KEY) { ExitCashCommand(200.DOLLARS) }
            contract `fails requirement` "for issuer MiniCorp the amounts balance"

            arg(MINI_CORP_KEY) { ExitCashCommand(200.DOLLARS) }
            contract.accepts()
        }
    }

    @Test
    fun multiIssuer() {
        transaction {
            // Gather 2000 dollars from two different issuers.
            input { inState }
            input { inState.copy(issuingInstitution = MINI_CORP) }

            // Can't merge them together.
            transaction {
                output { inState.copy(owner = DUMMY_PUBKEY_2, amount = 2000.DOLLARS) }
                contract `fails requirement` "for issuer MegaCorp the amounts balance"
            }
            // Missing MiniCorp deposit
            transaction {
                output { inState.copy(owner = DUMMY_PUBKEY_2) }
                output { inState.copy(owner = DUMMY_PUBKEY_2) }
                contract `fails requirement` "for issuer MegaCorp the amounts balance"
            }

            // This works.
            output { inState.copy(owner = DUMMY_PUBKEY_2) }
            output { inState.copy(issuingInstitution = MINI_CORP, owner = DUMMY_PUBKEY_2) }
            arg(DUMMY_PUBKEY_1) { MoveCashCommand() }
            contract.accepts()
        }

        transaction {
            input { inState }
            input { inState }
        }
    }
}