diff --git a/docs/source/tutorial-test-dsl.rst b/docs/source/tutorial-test-dsl.rst index 9df0c146af..6e6d98c9ab 100644 --- a/docs/source/tutorial-test-dsl.rst +++ b/docs/source/tutorial-test-dsl.rst @@ -1,6 +1,6 @@ .. highlight:: kotlin .. role:: kotlin(code) - :language: kotlin + :language: kotlin .. raw:: html @@ -10,7 +10,7 @@ Writing a contract test ======================= -This tutorial will take you through the steps required to write a contract test using Kotlin and/or Java. +This tutorial will take you through the steps required to write a contract test using Kotlin and Java. The testing DSL allows one to define a piece of the ledger with transactions referring to each other, and ways of verifying their correctness. @@ -24,10 +24,13 @@ We start with the empty ledger: .. sourcecode:: kotlin - @Test - fun emptyLedger() { - ledger { + class CommercialPaperTest{ + @Test + fun emptyLedger() { + ledger { + } } + ... } .. sourcecode:: java @@ -45,18 +48,43 @@ We start with the empty ledger: The DSL keyword ``ledger`` takes a closure that can build up several transactions and may verify their overall correctness. A ledger is effectively a fresh world with no pre-existing transactions or services within it. -Let's add a Cash transaction: +We will start with defining helper function that returns a ``CommercialPaper`` state: + +.. container:: codeset + + .. sourcecode:: kotlin + + fun getPaper(): ICommercialPaperState = CommercialPaper.State( + issuance = MEGA_CORP.ref(123), + owner = MEGA_CORP_PUBKEY, + faceValue = 1000.DOLLARS `issued by` MEGA_CORP.ref(123), + maturityDate = TEST_TX_TIME + 7.days + ) + + .. sourcecode:: java + + private final OpaqueBytes defaultRef = new OpaqueBytes(new byte[]{123}); + + private ICommercialPaperState getPaper() { + return new JavaCommercialPaper.State( + getMEGA_CORP().ref(defaultRef), + getMEGA_CORP_PUBKEY(), + issuedBy(DOLLARS(1000), getMEGA_CORP().ref(defaultRef)), + getTEST_TX_TIME().plus(7, ChronoUnit.DAYS) + ); + } + +It's a ``CommercialPaper`` issued by ``MEGA_CORP`` with face value of $1000 and maturity date in 7 days. + +Let's add a ``CommercialPaper`` transaction: .. container:: codeset .. sourcecode:: kotlin @Test - fun simpleCashDoesntCompile() { - val inState = Cash.State( - amount = 1000.DOLLARS `issued by` DUMMY_CASH_ISSUER, - owner = DUMMY_PUBKEY_1 - ) + fun simpleCPDoesntCompile() { + val inState = getPaper() ledger { transaction { input(inState) @@ -67,11 +95,8 @@ Let's add a Cash transaction: .. sourcecode:: java @Test - public void simpleCashDoesntCompile() { - Cash.State inState = new Cash.State( - issuedBy(DOLLARS(1000), getDUMMY_CASH_ISSUER()), - getDUMMY_PUBKEY_1() - ); + public void simpleCPDoesntCompile() { + ICommercialPaperState inState = getPaper(); ledger(l -> { l.transaction(tx -> { tx.input(inState); @@ -83,7 +108,7 @@ Let's add a Cash transaction: We can add a transaction to the ledger using the ``transaction`` primitive. The transaction in turn may be defined by specifying ``input``-s, ``output``-s, ``command``-s and ``attachment``-s. -The above ``input`` call is a bit special: Transactions don't actually contain input states, just references +The above ``input`` call is a bit special; transactions don't actually contain input states, just references to output states of other transactions. Under the hood the above ``input`` call creates a dummy transaction in the ledger (that won't be verified) which outputs the specified state, and references that from this transaction. @@ -93,11 +118,11 @@ The above code however doesn't compile: .. sourcecode:: kotlin - Error:(26, 21) Kotlin: Type mismatch: inferred type is Unit but EnforceVerifyOrFail was expected + Error:(29, 17) Kotlin: Type mismatch: inferred type is Unit but EnforceVerifyOrFail was expected .. sourcecode:: java - Error:(26, 31) java: incompatible types: bad return type in lambda expression missing return value + Error:(35, 27) java: incompatible types: bad return type in lambda expression missing return value This is deliberate: The DSL forces us to specify either ``this.verifies()`` or ``this `fails with` "some text"`` on the last line of ``transaction``: @@ -107,11 +132,8 @@ last line of ``transaction``: .. sourcecode:: kotlin @Test - fun simpleCash() { - val inState = Cash.State( - amount = 1000.DOLLARS `issued by` MEGA_CORP.ref(1, 1), - owner = DUMMY_PUBKEY_1 - ) + fun simpleCP() { + val inState = getPaper() ledger { transaction { input(inState) @@ -123,11 +145,8 @@ last line of ``transaction``: .. sourcecode:: java @Test - public void simpleCash() { - Cash.State inState = new Cash.State( - issuedBy(DOLLARS(1000), getMEGA_CORP().ref((byte)1, (byte)1)), - getDUMMY_PUBKEY_1() - ); + public void simpleCP() { + ICommercialPaperState inState = getPaper(); ledger(l -> { l.transaction(tx -> { tx.input(inState); @@ -137,30 +156,20 @@ last line of ``transaction``: }); } -The code finally compiles. When run, it produces the following error:: - - net.corda.core.contracts.TransactionVerificationException$ContractRejection: java.lang.IllegalArgumentException: Failed requirement: for deposit [01] at issuer Snake Oil Issuer the amounts balance - -.. note:: The reference here to the 'Snake Oil Issuer' is because we are using the pre-canned ``DUMMY_CASH_ISSUER`` - identity as the issuer of our cash. - -The transaction verification failed, because the sum of inputs does not equal the sum of outputs. We can specify that -this is intended behaviour by changing ``this.verifies()`` to ``this `fails with` "the amounts balance"``: +Let's take a look at a transaction that fails. .. container:: codeset .. sourcecode:: kotlin @Test - fun simpleCashFailsWith() { - val inState = Cash.State( - amount = 1000.DOLLARS `issued by` MEGA_CORP.ref(1, 1), - owner = DUMMY_PUBKEY_1 - ) + fun simpleCPMove() { + val inState = getPaper() ledger { transaction { input(inState) - this `fails with` "the amounts balance" + command(MEGA_CORP_PUBKEY) { CommercialPaper.Commands.Move() } + this.verifies() } } } @@ -168,15 +177,59 @@ this is intended behaviour by changing ``this.verifies()`` to ``this `fails with .. sourcecode:: java @Test - public void simpleCashFailsWith() { - Cash.State inState = new Cash.State( - issuedBy(DOLLARS(1000), getMEGA_CORP().ref((byte)1, (byte)1)), - getDUMMY_PUBKEY_1() - ); + public void simpleCPMove() { + ICommercialPaperState inState = getPaper(); ledger(l -> { l.transaction(tx -> { tx.input(inState); - return tx.failsWith("the amounts balance"); + tx.command(getMEGA_CORP_PUBKEY(), new JavaCommercialPaper.Commands.Move()); + return tx.verifies(); + }); + return Unit.INSTANCE; + }); + } + +When run, that code produces the following error: + +.. container:: codeset + + .. sourcecode:: kotlin + + net.corda.core.contracts.TransactionVerificationException$ContractRejection: java.lang.IllegalArgumentException: Failed requirement: the state is propagated + + .. sourcecode:: java + + net.corda.core.contracts.TransactionVerificationException$ContractRejection: java.lang.IllegalStateException: the state is propagated + +The transaction verification failed, because we wanted to move paper but didn't specify an output - but the state should be propagated. +However we can specify that this is an intended behaviour by changing ``this.verifies()`` to ``this `fails with` "the state is propagated"``: + +.. container:: codeset + + .. sourcecode:: kotlin + + @Test + fun simpleCPMoveFails() { + val inState = getPaper() + ledger { + transaction { + input(inState) + command(MEGA_CORP_PUBKEY) { CommercialPaper.Commands.Move() } + this `fails with` "the state is propagated" + } + } + } + + .. sourcecode:: java + + @Test + public void simpleCPMoveFails() { + ICommercialPaperState inState = getPaper(); + ledger(l -> { + l.transaction(tx -> { + tx.input(inState); + tx.command(getMEGA_CORP_PUBKEY(), new JavaCommercialPaper.Commands.Move()); + return tx.failsWith("the state is propagated"); }); return Unit.INSTANCE; }); @@ -189,17 +242,14 @@ We can continue to build the transaction until it ``verifies``: .. sourcecode:: kotlin @Test - fun simpleCashSuccess() { - val inState = Cash.State( - amount = 1000.DOLLARS `issued by` MEGA_CORP.ref(1, 1), - owner = DUMMY_PUBKEY_1 - ) + fun simpleCPMoveSuccess() { + val inState = getPaper() ledger { transaction { input(inState) - this `fails with` "the amounts balance" - output(inState.copy(owner = DUMMY_PUBKEY_2)) - command(DUMMY_PUBKEY_1) { Cash.Commands.Move() } + command(MEGA_CORP_PUBKEY) { CommercialPaper.Commands.Move() } + this `fails with` "the state is propagated" + output("alice's paper") { inState `owned by` ALICE_PUBKEY } this.verifies() } } @@ -208,55 +258,45 @@ We can continue to build the transaction until it ``verifies``: .. sourcecode:: java @Test - public void simpleCashSuccess() { - Cash.State inState = new Cash.State( - issuedBy(DOLLARS(1000), getMEGA_CORP().ref((byte)1, (byte)1)), - getDUMMY_PUBKEY_1() - ); + public void simpleCPMoveSuccess() { + ICommercialPaperState inState = getPaper(); ledger(l -> { l.transaction(tx -> { tx.input(inState); - tx.failsWith("the amounts balance"); - tx.output(inState.copy(inState.getAmount(), getDUMMY_PUBKEY_2())); - tx.command(getDUMMY_PUBKEY_1(), new Cash.Commands.Move()); + tx.command(getMEGA_CORP_PUBKEY(), new JavaCommercialPaper.Commands.Move()); + tx.failsWith("the state is propagated"); + tx.output("alice's paper", inState.withOwner(getALICE_PUBKEY())); return tx.verifies(); }); return Unit.INSTANCE; }); } -``output`` specifies that we want the input state to be transferred to ``DUMMY_PUBKEY_2`` and ``command`` adds the -``Move`` command itself, signed by the current owner of the input state, ``DUMMY_PUBKEY_1``. +``output`` specifies that we want the input state to be transferred to ``ALICE`` and ``command`` adds the +``Move`` command itself, signed by the current owner of the input state, ``MEGA_CORP_PUBKEY``. -We constructed a complete signed cash transaction from ``DUMMY_PUBKEY_1`` to ``DUMMY_PUBKEY_2`` and verified it. Note -how we left in the ``fails with`` line - this is fine, the failure will be tested on the partially constructed -transaction. +We constructed a complete signed commercial paper transaction and verified it. Note how we left in the ``fails with`` +line - this is fine, the failure will be tested on the partially constructed transaction. What should we do if we wanted to test what happens when the wrong party signs the transaction? If we simply add a -``command`` it will ruin the transaction for good... Enter ``tweak``: +``command`` it will permanently ruin the transaction... Enter ``tweak``: .. container:: codeset .. sourcecode:: kotlin @Test - fun simpleCashTweakSuccess() { - val inState = Cash.State( - amount = 1000.DOLLARS `issued by` MEGA_CORP.ref(1, 1), - owner = DUMMY_PUBKEY_1 - ) + fun `simple issuance with tweak`() { ledger { transaction { - input(inState) - this `fails with` "the amounts balance" - output(inState.copy(owner = DUMMY_PUBKEY_2)) - + output("paper") { getPaper() } // Some CP is issued onto the ledger by MegaCorp. tweak { - command(DUMMY_PUBKEY_2) { Cash.Commands.Move() } - this `fails with` "the owning keys are the same as the signing keys" + command(DUMMY_PUBKEY_1) { CommercialPaper.Commands.Issue() } + timestamp(TEST_TX_TIME) + this `fails with` "output states are issued by a command signer" } - - command(DUMMY_PUBKEY_1) { Cash.Commands.Move() } + command(MEGA_CORP_PUBKEY) { CommercialPaper.Commands.Issue() } + timestamp(TEST_TX_TIME) this.verifies() } } @@ -265,33 +305,29 @@ What should we do if we wanted to test what happens when the wrong party signs t .. sourcecode:: java @Test - public void simpleCashTweakSuccess() { - Cash.State inState = new Cash.State( - issuedBy(DOLLARS(1000), getMEGA_CORP().ref((byte)1, (byte)1)), - getDUMMY_PUBKEY_1() - ); + public void simpleIssuanceWithTweak() { ledger(l -> { l.transaction(tx -> { - tx.input(inState); - tx.failsWith("the amounts balance"); - tx.output(inState.copy(inState.getAmount(), getDUMMY_PUBKEY_2())); - + tx.output("paper", getPaper()); // Some CP is issued onto the ledger by MegaCorp. tx.tweak(tw -> { - tw.command(getDUMMY_PUBKEY_2(), new Cash.Commands.Move()); - return tw.failsWith("the owning keys are the same as the signing keys"); + tw.command(getDUMMY_PUBKEY_1(), new JavaCommercialPaper.Commands.Issue()); + tw.timestamp(getTEST_TX_TIME()); + return tw.failsWith("output states are issued by a command signer"); }); - tx.command(getDUMMY_PUBKEY_1(), new Cash.Commands.Move()); + tx.command(getMEGA_CORP_PUBKEY(), new JavaCommercialPaper.Commands.Issue()); + tx.timestamp(getTEST_TX_TIME()); return tx.verifies(); }); return Unit.INSTANCE; }); } -``tweak`` creates a local copy of the transaction. This allows the local "ruining" of the transaction allowing testing -of different error conditions. + +``tweak`` creates a local copy of the transaction. This makes possible to locally "ruin" the transaction while not +modifying the original one, allowing testing of different error conditions. We now have a neat little test that tests a single transaction. This is already useful, and in fact testing of a single -transaction in this way is very common. There is even a shorthand toplevel ``transaction`` primitive that creates a +transaction in this way is very common. There is even a shorthand top-level ``transaction`` primitive that creates a ledger with a single transaction: .. container:: codeset @@ -299,22 +335,16 @@ ledger with a single transaction: .. sourcecode:: kotlin @Test - fun simpleCashTweakSuccessTopLevelTransaction() { - val inState = Cash.State( - amount = 1000.DOLLARS `issued by` MEGA_CORP.ref(1, 1), - owner = DUMMY_PUBKEY_1 - ) + fun `simple issuance with tweak and top level transaction`() { transaction { - input(inState) - this `fails with` "the amounts balance" - output(inState.copy(owner = DUMMY_PUBKEY_2)) - + output("paper") { getPaper() } // Some CP is issued onto the ledger by MegaCorp. tweak { - command(DUMMY_PUBKEY_2) { Cash.Commands.Move() } - this `fails with` "the owning keys are the same as the signing keys" + command(DUMMY_PUBKEY_1) { CommercialPaper.Commands.Issue() } + timestamp(TEST_TX_TIME) + this `fails with` "output states are issued by a command signer" } - - command(DUMMY_PUBKEY_1) { Cash.Commands.Move() } + command(MEGA_CORP_PUBKEY) { CommercialPaper.Commands.Issue() } + timestamp(TEST_TX_TIME) this.verifies() } } @@ -322,21 +352,16 @@ ledger with a single transaction: .. sourcecode:: java @Test - public void simpleCashTweakSuccessTopLevelTransaction() { - Cash.State inState = new Cash.State( - issuedBy(DOLLARS(1000), getMEGA_CORP().ref((byte)1, (byte)1)), - getDUMMY_PUBKEY_1() - ); + public void simpleIssuanceWithTweakTopLevelTx() { transaction(tx -> { - tx.input(inState); - tx.failsWith("the amounts balance"); - tx.output(inState.copy(inState.getAmount(), getDUMMY_PUBKEY_2())); - + tx.output("paper", getPaper()); // Some CP is issued onto the ledger by MegaCorp. tx.tweak(tw -> { - tw.command(getDUMMY_PUBKEY_2(), new Cash.Commands.Move()); - return tw.failsWith("the owning keys are the same as the signing keys"); + tw.command(getDUMMY_PUBKEY_1(), new JavaCommercialPaper.Commands.Issue()); + tw.timestamp(getTEST_TX_TIME()); + return tw.failsWith("output states are issued by a command signer"); }); - tx.command(getDUMMY_PUBKEY_1(), new Cash.Commands.Move()); + tx.command(getMEGA_CORP_PUBKEY(), new JavaCommercialPaper.Commands.Issue()); + tx.timestamp(getTEST_TX_TIME()); return tx.verifies(); }); } @@ -351,21 +376,30 @@ Now that we know how to define a single transaction, let's look at how to define .. sourcecode:: kotlin @Test - fun chainCash() { + fun `chain commercial paper`() { + val issuer = MEGA_CORP.ref(123) + ledger { unverifiedTransaction { - output("MEGA_CORP cash") { - Cash.State( - amount = 1000.DOLLARS `issued by` MEGA_CORP.ref(1, 1), - owner = MEGA_CORP_PUBKEY - ) - } + output("alice's $900", 900.DOLLARS.CASH `issued by` issuer `owned by` ALICE_PUBKEY) } - transaction { - input("MEGA_CORP cash") - output("MEGA_CORP cash".output().copy(owner = DUMMY_PUBKEY_1)) - command(MEGA_CORP_PUBKEY) { Cash.Commands.Move() } + // Some CP is issued onto the ledger by MegaCorp. + transaction("Issuance") { + output("paper") { getPaper() } + command(MEGA_CORP_PUBKEY) { CommercialPaper.Commands.Issue() } + timestamp(TEST_TX_TIME) + this.verifies() + } + + + transaction("Trade") { + input("paper") + input("alice's $900") + output("borrowed $900") { 900.DOLLARS.CASH `issued by` issuer `owned by` MEGA_CORP_PUBKEY } + output("alice's paper") { "paper".output() `owned by` ALICE_PUBKEY } + command(ALICE_PUBKEY) { Cash.Commands.Move() } + command(MEGA_CORP_PUBKEY) { CommercialPaper.Commands.Move() } this.verifies() } } @@ -374,141 +408,176 @@ Now that we know how to define a single transaction, let's look at how to define .. sourcecode:: java @Test - public void chainCash() { + public void chainCommercialPaper() { + PartyAndReference issuer = getMEGA_CORP().ref(defaultRef); ledger(l -> { l.unverifiedTransaction(tx -> { - tx.output("MEGA_CORP cash", - new Cash.State( - issuedBy(DOLLARS(1000), getMEGA_CORP().ref((byte)1, (byte)1)), - getMEGA_CORP_PUBKEY() - ) - ); - return Unit.INSTANCE; - }); + tx.output("alice's $900", + new Cash.State(issuedBy(DOLLARS(900), issuer), getALICE_PUBKEY(), null)); + return Unit.INSTANCE; + }); - l.transaction(tx -> { - tx.input("MEGA_CORP cash"); - Cash.State inputCash = l.retrieveOutput(Cash.State.class, "MEGA_CORP cash"); - tx.output(inputCash.copy(inputCash.getAmount(), getDUMMY_PUBKEY_1())); - tx.command(getMEGA_CORP_PUBKEY(), new Cash.Commands.Move()); + // Some CP is issued onto the ledger by MegaCorp. + l.transaction("Issuance", tx -> { + tx.output("paper", getPaper()); + tx.command(getMEGA_CORP_PUBKEY(), new JavaCommercialPaper.Commands.Issue()); + tx.timestamp(getTEST_TX_TIME()); return tx.verifies(); }); + l.transaction("Trade", tx -> { + tx.input("paper"); + tx.input("alice's $900"); + tx.output("borrowed $900", new Cash.State(issuedBy(DOLLARS(900), issuer), getMEGA_CORP_PUBKEY(), null)); + JavaCommercialPaper.State inputPaper = l.retrieveOutput(JavaCommercialPaper.State.class, "paper"); + tx.output("alice's paper", inputPaper.withOwner(getALICE_PUBKEY())); + tx.command(getALICE_PUBKEY(), new Cash.Commands.Move()); + tx.command(getMEGA_CORP_PUBKEY(), new JavaCommercialPaper.Commands.Move()); + return tx.verifies(); + }); return Unit.INSTANCE; }); } -In this example we declare that ``MEGA_CORP`` has a thousand dollars but we don't care where from, for this we can use + +In this example we declare that ``ALICE`` has $900 but we don't care where from. For this we can use ``unverifiedTransaction``. Note how we don't need to specify ``this.verifies()``. -The ``output`` cash was labelled with ``"MEGA_CORP cash"``, we can subsequently referred to this other transactions, e.g. -by ``input("MEGA_CORP cash")`` or ``"MEGA_CORP cash".output()``. +Notice that we labelled output with ``"alice's $900"``, also in transaction named ``"Issuance"`` +we labelled a commercial paper with ``"paper"``. Now we can subsequently refer to them in other transactions, e.g. +by ``input("alice's $900")`` or ``"paper".output()``. -What happens if we reuse the output cash twice? +The last transaction named ``"Trade"`` exemplifies simple fact of selling the ``CommercialPaper`` to Alice for her $900, +$100 less than the face value at 10% interest after only 7 days. + +We can also test whole ledger calling ``this.verifies()`` and ``this.fails()`` on the ledger level. +To do so let's create a simple example that uses the same input twice: .. container:: codeset .. sourcecode:: kotlin @Test - fun chainCashDoubleSpend() { + fun `chain commercial paper double spend`() { + val issuer = MEGA_CORP.ref(123) ledger { unverifiedTransaction { - output("MEGA_CORP cash") { - Cash.State( - amount = 1000.DOLLARS `issued by` MEGA_CORP.ref(1, 1), - owner = MEGA_CORP_PUBKEY - ) - } + output("alice's $900", 900.DOLLARS.CASH `issued by` issuer `owned by` ALICE_PUBKEY) } - transaction { - input("MEGA_CORP cash") - output("MEGA_CORP cash".output().copy(owner = DUMMY_PUBKEY_1)) - command(MEGA_CORP_PUBKEY) { Cash.Commands.Move() } + // Some CP is issued onto the ledger by MegaCorp. + transaction("Issuance") { + output("paper") { getPaper() } + command(MEGA_CORP_PUBKEY) { CommercialPaper.Commands.Issue() } + timestamp(TEST_TX_TIME) + this.verifies() + } + + transaction("Trade") { + input("paper") + input("alice's $900") + output("borrowed $900") { 900.DOLLARS.CASH `issued by` issuer `owned by` MEGA_CORP_PUBKEY } + output("alice's paper") { "paper".output() `owned by` ALICE_PUBKEY } + command(ALICE_PUBKEY) { Cash.Commands.Move() } + command(MEGA_CORP_PUBKEY) { CommercialPaper.Commands.Move() } this.verifies() } transaction { - input("MEGA_CORP cash") - // We send it to another pubkey so that the transaction is not identical to the previous one - output("MEGA_CORP cash".output().copy(owner = DUMMY_PUBKEY_2)) - command(MEGA_CORP_PUBKEY) { Cash.Commands.Move() } + input("paper") + // We moved a paper to another pubkey. + output("bob's paper") { "paper".output() `owned by` BOB_PUBKEY } + command(MEGA_CORP_PUBKEY) { CommercialPaper.Commands.Move() } this.verifies() } + + this.fails() } } .. sourcecode:: java @Test - public void chainCashDoubleSpend() { + public void chainCommercialPaperDoubleSpend() { + PartyAndReference issuer = getMEGA_CORP().ref(defaultRef); ledger(l -> { l.unverifiedTransaction(tx -> { - tx.output("MEGA_CORP cash", - new Cash.State( - issuedBy(DOLLARS(1000), getMEGA_CORP().ref((byte)1, (byte)1)), - getMEGA_CORP_PUBKEY() - ) - ); + tx.output("alice's $900", + new Cash.State(issuedBy(DOLLARS(900), issuer), getALICE_PUBKEY(), null)); return Unit.INSTANCE; }); - l.transaction(tx -> { - tx.input("MEGA_CORP cash"); - Cash.State inputCash = l.retrieveOutput(Cash.State.class, "MEGA_CORP cash"); - tx.output(inputCash.copy(inputCash.getAmount(), getDUMMY_PUBKEY_1())); - tx.command(getMEGA_CORP_PUBKEY(), new Cash.Commands.Move()); + // Some CP is issued onto the ledger by MegaCorp. + l.transaction("Issuance", tx -> { + tx.output("paper", getPaper()); + tx.command(getMEGA_CORP_PUBKEY(), new JavaCommercialPaper.Commands.Issue()); + tx.timestamp(getTEST_TX_TIME()); + return tx.verifies(); + }); + + l.transaction("Trade", tx -> { + tx.input("paper"); + tx.input("alice's $900"); + tx.output("borrowed $900", new Cash.State(issuedBy(DOLLARS(900), issuer), getMEGA_CORP_PUBKEY(), null)); + JavaCommercialPaper.State inputPaper = l.retrieveOutput(JavaCommercialPaper.State.class, "paper"); + tx.output("alice's paper", inputPaper.withOwner(getALICE_PUBKEY())); + tx.command(getALICE_PUBKEY(), new Cash.Commands.Move()); + tx.command(getMEGA_CORP_PUBKEY(), new JavaCommercialPaper.Commands.Move()); return tx.verifies(); }); l.transaction(tx -> { - tx.input("MEGA_CORP cash"); - Cash.State inputCash = l.retrieveOutput(Cash.State.class, "MEGA_CORP cash"); - // We send it to another pubkey so that the transaction is not identical to the previous one - tx.output(inputCash.copy(inputCash.getAmount(), getDUMMY_PUBKEY_2())); - tx.command(getMEGA_CORP_PUBKEY(), new Cash.Commands.Move()); + tx.input("paper"); + JavaCommercialPaper.State inputPaper = l.retrieveOutput(JavaCommercialPaper.State.class, "paper"); + // We moved a paper to other pubkey. + tx.output("bob's paper", inputPaper.withOwner(getBOB_PUBKEY())); + tx.command(getMEGA_CORP_PUBKEY(), new JavaCommercialPaper.Commands.Move()); return tx.verifies(); }); - + l.fails(); return Unit.INSTANCE; }); } -The transactions ``verifies()`` individually, however the state was spent twice! - -We can also verify the complete ledger by calling ``verifies``/``fails`` on the ledger level. We can also use -``tweak`` to create a local copy of the whole ledger: +The transactions ``verifies()`` individually, however the state was spent twice! That's why we need the global ledger +verification (``this.fails()`` at the end). As in previous examples we can use ``tweak`` to create a local copy of the whole ledger: .. container:: codeset .. sourcecode:: kotlin @Test - fun chainCashDoubleSpendFailsWith() { + fun `chain commercial tweak`() { + val issuer = MEGA_CORP.ref(123) ledger { unverifiedTransaction { - output("MEGA_CORP cash") { - Cash.State( - amount = 1000.DOLLARS `issued by` MEGA_CORP.ref(1, 1), - owner = MEGA_CORP_PUBKEY - ) - } + output("alice's $900", 900.DOLLARS.CASH `issued by` issuer `owned by` ALICE_PUBKEY) } - transaction { - input("MEGA_CORP cash") - output("MEGA_CORP cash".output().copy(owner = DUMMY_PUBKEY_1)) - command(MEGA_CORP_PUBKEY) { Cash.Commands.Move() } + // Some CP is issued onto the ledger by MegaCorp. + transaction("Issuance") { + output("paper") { getPaper() } + command(MEGA_CORP_PUBKEY) { CommercialPaper.Commands.Issue() } + timestamp(TEST_TX_TIME) + this.verifies() + } + + transaction("Trade") { + input("paper") + input("alice's $900") + output("borrowed $900") { 900.DOLLARS.CASH `issued by` issuer `owned by` MEGA_CORP_PUBKEY } + output("alice's paper") { "paper".output() `owned by` ALICE_PUBKEY } + command(ALICE_PUBKEY) { Cash.Commands.Move() } + command(MEGA_CORP_PUBKEY) { CommercialPaper.Commands.Move() } this.verifies() } tweak { transaction { - input("MEGA_CORP cash") - // We send it to another pubkey so that the transaction is not identical to the previous one - output("MEGA_CORP cash".output().copy(owner = DUMMY_PUBKEY_1)) - command(MEGA_CORP_PUBKEY) { Cash.Commands.Move() } + input("paper") + // We moved a paper to another pubkey. + output("bob's paper") { "paper".output() `owned by` BOB_PUBKEY } + command(MEGA_CORP_PUBKEY) { CommercialPaper.Commands.Move() } this.verifies() } this.fails() @@ -521,39 +590,46 @@ We can also verify the complete ledger by calling ``verifies``/``fails`` on the .. sourcecode:: java @Test - public void chainCashDoubleSpendFailsWith() { + public void chainCommercialPaperTweak() { + PartyAndReference issuer = getMEGA_CORP().ref(defaultRef); ledger(l -> { l.unverifiedTransaction(tx -> { - tx.output("MEGA_CORP cash", - new Cash.State( - issuedBy(DOLLARS(1000), getMEGA_CORP().ref((byte)1, (byte)1)), - getMEGA_CORP_PUBKEY() - ) - ); + tx.output("alice's $900", + new Cash.State(issuedBy(DOLLARS(900), issuer), getALICE_PUBKEY(), null)); return Unit.INSTANCE; }); - l.transaction(tx -> { - tx.input("MEGA_CORP cash"); - Cash.State inputCash = l.retrieveOutput(Cash.State.class, "MEGA_CORP cash"); - tx.output(inputCash.copy(inputCash.getAmount(), getDUMMY_PUBKEY_1())); - tx.command(getMEGA_CORP_PUBKEY(), new Cash.Commands.Move()); + // Some CP is issued onto the ledger by MegaCorp. + l.transaction("Issuance", tx -> { + tx.output("paper", getPaper()); + tx.command(getMEGA_CORP_PUBKEY(), new JavaCommercialPaper.Commands.Issue()); + tx.timestamp(getTEST_TX_TIME()); + return tx.verifies(); + }); + + l.transaction("Trade", tx -> { + tx.input("paper"); + tx.input("alice's $900"); + tx.output("borrowed $900", new Cash.State(issuedBy(DOLLARS(900), issuer), getMEGA_CORP_PUBKEY(), null)); + JavaCommercialPaper.State inputPaper = l.retrieveOutput(JavaCommercialPaper.State.class, "paper"); + tx.output("alice's paper", inputPaper.withOwner(getALICE_PUBKEY())); + tx.command(getALICE_PUBKEY(), new Cash.Commands.Move()); + tx.command(getMEGA_CORP_PUBKEY(), new JavaCommercialPaper.Commands.Move()); return tx.verifies(); }); l.tweak(lw -> { lw.transaction(tx -> { - tx.input("MEGA_CORP cash"); - Cash.State inputCash = l.retrieveOutput(Cash.State.class, "MEGA_CORP cash"); - // We send it to another pubkey so that the transaction is not identical to the previous one - tx.output(inputCash.copy(inputCash.getAmount(), getDUMMY_PUBKEY_2())); - tx.command(getMEGA_CORP_PUBKEY(), new Cash.Commands.Move()); + tx.input("paper"); + JavaCommercialPaper.State inputPaper = l.retrieveOutput(JavaCommercialPaper.State.class, "paper"); + // We moved a paper to another pubkey. + tx.output("bob's paper", inputPaper.withOwner(getBOB_PUBKEY())); + tx.command(getMEGA_CORP_PUBKEY(), new JavaCommercialPaper.Commands.Move()); return tx.verifies(); }); lw.fails(); return Unit.INSTANCE; }); - l.verifies(); return Unit.INSTANCE; });