Contracts: add an issue crafting function to the cash contract.

src/contracts/Cash.kt

@@ -136,6 +136,16 @@ object Cash : Contract {
         }
     }
 
+    /**
+     * Puts together an issuance transaction for the specified amount that starts out being owned by the given pubkey.
+     */
+    fun craftIssue(tx: PartialTransaction, amount: Amount, at: InstitutionReference, owner: PublicKey) {
+        check(tx.inputStates().isEmpty())
+        check(tx.outputStates().sumCashOrNull() == null)
+        tx.addOutputState(Cash.State(at, amount, owner))
+        tx.addArg(WireCommand(Cash.Commands.Issue(), listOf(at.institution.owningKey)))
+    }
+
     /**
      * Generate a transaction that consumes one or more of the given input states to move money to the given pubkey.
      * Note that the wallet list is not updated: it's up to you to do that.

src/core/Transactions.kt

@@ -108,6 +108,11 @@ class PartialTransaction(private val inputStates: MutableList<ContractStateRef>
         check(currentSigs.isEmpty())
         args.add(arg)
     }
+
+    // Accessors that yield immutable snapshots.
+    fun inputStates(): List<ContractStateRef> = ArrayList(inputStates)
+    fun outputStates(): List<ContractState> = ArrayList(outputStates)
+    fun args(): List<WireCommand> = ArrayList(args)
 }
 
 

tests/contracts/CashTests.kt

@@ -8,6 +8,7 @@ import java.security.PublicKey
 import java.util.*
 import kotlin.test.assertEquals
 import kotlin.test.assertFailsWith
+import kotlin.test.assertTrue
 
 class CashTests {
     val inState = Cash.State(
@@ -87,6 +88,16 @@ class CashTests {
             arg(MINI_CORP_KEY) { Cash.Commands.Issue() }
             this.accepts()
         }
+
+        val ptx = PartialTransaction()
+        Cash.craftIssue(ptx, 100.DOLLARS, InstitutionReference(MINI_CORP, OpaqueBytes.of(12, 34)), owner = DUMMY_PUBKEY_1)
+        assertTrue(ptx.inputStates().isEmpty())
+        val s = ptx.outputStates()[0] as Cash.State
+        assertEquals(100.DOLLARS, s.amount)
+        assertEquals(MINI_CORP, s.deposit.institution)
+        assertEquals(DUMMY_PUBKEY_1, s.owner)
+        assertTrue(ptx.args()[0].command is Cash.Commands.Issue)
+        assertEquals(MINI_CORP_KEY, ptx.args()[0].pubkeys[0])
     }
 
     @Test