Add convenience initializer to Outcome

nitro/protocol/outcome.nim

@@ -19,13 +19,23 @@ type
     of guaranteeType:
       guarantee*: Guarantee
   Allocation* = distinct seq[AllocationItem]
-  AllocationItem* = object
-    destination*: Destination
-    amount*: UInt256
+  AllocationItem* = tuple
+    destination: Destination
+    amount: UInt256
   Guarantee* = object
     targetChannelId*: Destination
     destinations*: seq[Destination]
 
+proc init*(_: type Outcome,
+           asset: EthAddress,
+           allocation: openArray[AllocationItem]): Outcome =
+  let assetOutcome = AssetOutcome(
+    kind: allocationType,
+    assetHolder: asset,
+    allocation: Allocation(@allocation)
+  )
+  Outcome(@[assetOutcome])
+
 proc encode*(encoder: var AbiEncoder, guarantee: Guarantee) =
   encoder.startTuple()
   encoder.startTuple()

tests/nitro/examples.nim

@@ -38,10 +38,7 @@ proc example*(_: type ChannelDefinition): ChannelDefinition =
   )
 
 proc example*(_: type AllocationItem): AllocationItem =
-  AllocationItem(
-    destination: Destination.example,
-    amount: UInt256.example
-  )
+  (Destination.example, UInt256.example)
 
 proc example*(_: type Guarantee): Guarantee =
   Guarantee(

tests/nitro/protocol/testOutcome.nim

@@ -94,7 +94,7 @@ suite "outcome":
           "1E90B49563da16D2537CA1Ddd9b1285279103D93"
         ).get(),
         allocation: Allocation(@[
-          AllocationItem(
+          (
             destination: Destination.parse(
               "f1918e8562236eb17adc8502332f4c9c82bc14e19bfc0aa10ab674ff75b3d2f3"
             ).get(),