Fix SingleOrList parser

tests/test_json_marshalling.nim

@@ -194,3 +194,18 @@ suite "JSON-RPC Quantity":
     let c = JrpcConv.decode(x, RtBlockIdentifier)
     check c.kind == bidNumber
     check c.number == 77
+
+    let d = JrpcConv.decode("\"10\"", RtBlockIdentifier)
+    check d.kind == bidAlias
+    check d.alias == "10"
+
+    expect JsonReaderError:
+      let d = JrpcConv.decode("10", RtBlockIdentifier)
+      discard d
+
+  test "check address or list":
+    let a = AddressOrList(kind: slkNull)
+    let x = JrpcConv.encode(a)
+    let c = JrpcConv.decode(x, AddressOrList)
+    check c.kind == slkNull
+

web3/conversions.nim

@@ -154,6 +154,10 @@ func valid(hex: string): bool =
   if hex.len >= 2:
     if hex[0] == '0' and hex[1] in {'x', 'X'}:
       start = 2
+    else:
+      return false
+  else:
+    return false
 
   for i in start..<hex.len:
     let x = hex[i]
@@ -329,6 +333,7 @@ proc readValue*[T](r: var JsonReader[JrpcConv], val: var SingleOrList[T])
     r.readValue(val.list)
   of JsonValueKind.Null:
     val = SingleOrList[T](kind: slkNull)
+    r.parseNull()
   else:
     r.raiseUnexpectedValue("TopicOrList unexpected token kind =" & $tok)