Added EthAddressStr to validation

nimbus/rpc/hexstrings.nim

@@ -13,6 +13,11 @@
 type
   HexQuantityStr* = distinct string
   HexDataStr* = distinct string
+  EthAddressStr* = distinct string
+
+func len*(data: HexQuantityStr): int = data.string.len
+func len*(data: HexDataStr): int = data.string.len
+func len*(data: EthAddressStr): int = data.string.len
 
 # Hex validation
 
@@ -60,9 +65,14 @@ func isValidHexData*(value: string): bool =
       return false
   return true
 
+func isValidEthAddress*(value: string): bool =
+  # 20 bytes for EthAddress plus "0x"
+  result = value.len <= 42 and value.isValidHexData
+
 const
   SInvalidQuantity = "Invalid hex quantity format for Ethereum"
   SInvalidData = "Invalid hex data format for Ethereum"
+  SInvalidAddress = "Invalid address format for Ethereum"
 
 proc validateHexQuantity*(value: string) {.inline.} =
   if unlikely(not value.isValidHexQuantity):
@@ -72,6 +82,10 @@ proc validateHexData*(value: string) {.inline.} =
   if unlikely(not value.isValidHexData):
     raise newException(ValueError, SInvalidData & ": " & value)
 
+proc validateHexAddressStr*(value: string) {.inline.} =
+  if unlikely(not value.isValidEthAddress):
+    raise newException(ValueError, SInvalidAddress & ": " & value)
+
 # Initialisation
 
 proc hexQuantityStr*(value: string): HexQuantityStr {.inline.} =
@@ -82,6 +96,10 @@ proc hexDataStr*(value: string): HexDataStr {.inline.} =
   value.validateHexData
   result = value.HexDataStr
 
+proc ethAddressStr*(value: string): EthAddressStr {.inline.} =
+  value.validateHexAddressStr
+  result = value.EthAddressStr
+
 # Converters for use in RPC
 
 import json
@@ -93,6 +111,9 @@ proc `%`*(value: HexQuantityStr): JsonNode =
 proc `%`*(value: HexDataStr): JsonNode =
   result = %(value.string)
 
+proc `%`*(value: EthAddressStr): JsonNode =
+  result = %(value.string)
+
 proc fromJson*(n: JsonNode, argName: string, result: var HexQuantityStr) =
   # Note that '0x' is stripped after validation
   n.kind.expect(JString, argName)
@@ -106,6 +127,14 @@ proc fromJson*(n: JsonNode, argName: string, result: var HexDataStr) =
   n.kind.expect(JString, argName)
   let hexStr = n.getStr()
   if not hexStr.isValidHexData:
-    raise newException(ValueError, "Parameter \"" & argName & "\" is not valid as a Ethereum data \"" & hexStr & "\"")
+    raise newException(ValueError, "Parameter \"" & argName & "\" is not valid as Ethereum data \"" & hexStr & "\"")
   result = hexStr.hexDataStr
 
+proc fromJson*(n: JsonNode, argName: string, result: var EthAddressStr) =
+  # Note that '0x' is stripped after validation
+  n.kind.expect(JString, argName)
+  let hexStr = n.getStr()
+  if not hexStr.isValidEthAddress:
+    raise newException(ValueError, "Parameter \"" & argName & "\" is not valid as an Ethereum address \"" & hexStr & "\"")
+  result = hexStr.EthAddressStr
+