Fix decoding of events with dynamic arguments

Such as byte sequences or strings.

ethers.nimble

@@ -4,7 +4,7 @@ description = "library for interacting with Ethereum"
 license = "MIT"
 
 requires "chronos >= 3.0.0 & < 4.0.0"
-requires "contractabi >= 0.4.2 & < 0.5.0"
+requires "contractabi >= 0.4.4 & < 0.5.0"
 requires "questionable >= 0.10.2 & < 0.11.0"
 requires "upraises >= 0.1.0 & < 0.2.0"
 requires "json_rpc"

ethers/events.nim

@@ -26,9 +26,11 @@ template indexed* {.pragma.}
 
 func decode*[E: Event](decoder: var AbiDecoder, _: type E): ?!E =
   var event: E
+  decoder.startTuple()
   for field in event.fields:
     if not field.hasCustomPragma(indexed):
       field = ?decoder.read(typeof(field))
+  decoder.finishTuple()
   success event
 
 func decode*[E: Event](_: type E, data: seq[byte], topics: seq[Topic]): ?!E =

testmodule/testEvents.nim

@@ -9,6 +9,9 @@ suite "Events":
     SimpleEvent = object of Event
       a: UInt256
       b: Address
+    DynamicSizeEvent = object of Event
+      a: array[32, byte]
+      b: seq[byte]
     IndexedEvent = object of Event
       a: UInt256
       b {.indexed.}: Address
@@ -29,6 +32,12 @@ suite "Events":
       b: Address.example
     )
 
+  proc example(_: type DynamicSizeEvent): DynamicSizeEvent =
+    DynamicSizeEvent(
+      a: array[32, byte].example,
+      b: seq[byte].example
+    )
+
   proc example(_: type IndexedEvent): IndexedEvent =
     IndexedEvent(
       a: UInt256.example,
@@ -47,6 +56,11 @@ suite "Events":
     let data = AbiEncoder.encode( (event.a, event.b) )
     check SimpleEvent.decode(data, @[]) == success event
 
+  test "decodes dynamically sized fields":
+    let event = DynamicSizeEvent.example
+    let data = AbiEncoder.encode( (event.a, event.b) )
+    check DynamicSizeEvent.decode(data, @[]) == success event
+
   test "decodes indexed fields":
     let event = IndexedEvent.example
     var topics: seq[Topic]