From 26953344c3aa8606b903a4aacf27bb7d7b8bb026 Mon Sep 17 00:00:00 2001
From: Zahary Karadjov <zahary@gmail.com>
Date: Wed, 29 Aug 2018 15:44:30 +0300
Subject: [PATCH] Turn some potentially dangerous templates into functions

Be careful when creating templates. If the input parameters are
referenced within the body multiple times, this may lead to multiple
evaluations of functions with side-effects.
---
 json_rpc/jsonmarshal.nim | 4 ++--
 json_rpc/router.nim      | 2 +-
 tests/ethhexstrings.nim  | 8 +++++---
 3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/json_rpc/jsonmarshal.nim b/json_rpc/jsonmarshal.nim
index b38987a..1cf3849 100644
--- a/json_rpc/jsonmarshal.nim
+++ b/json_rpc/jsonmarshal.nim
@@ -1,9 +1,9 @@
 import macros, json, options, typetraits
 
-template expect*(actual, expected: JsonNodeKind, argName: string) =
+proc expect*(actual, expected: JsonNodeKind, argName: string) =
   if actual != expected: raise newException(ValueError, "Parameter [" & argName & "] expected " & $expected & " but got " & $actual)
 
-template expectType*(actual: JsonNodeKind, expected: typedesc, argName: string, allowNull = false) =
+proc expectType*(actual: JsonNodeKind, expected: typedesc, argName: string, allowNull = false) =
   var expType: JsonNodeKind
   when expected is array:
     expType = JArray
diff --git a/json_rpc/router.nim b/json_rpc/router.nim
index 92f04be..5d325c3 100644
--- a/json_rpc/router.nim
+++ b/json_rpc/router.nim
@@ -59,7 +59,7 @@ proc clear*(router: var RpcRouter) = router.procs.clear
 
 proc hasMethod*(router: RpcRouter, methodName: string): bool = router.procs.hasKey(methodName)
 
-template isEmpty(node: JsonNode): bool = node.isNil or node.kind == JNull
+func isEmpty(node: JsonNode): bool = node.isNil or node.kind == JNull
 
 # Json state checking
 
diff --git a/tests/ethhexstrings.nim b/tests/ethhexstrings.nim
index e97adf1..9fa859a 100644
--- a/tests/ethhexstrings.nim
+++ b/tests/ethhexstrings.nim
@@ -15,12 +15,14 @@ proc encodeQuantity*(value: SomeUnsignedInt): string =
   var hValue = value.toHex.stripLeadingZeros
   result = "0x" & hValue
 
-template hasHexHeader*(value: string | HexDataStr | HexQuantityStr): bool =
-  template strVal: untyped = value.string
+func hasHexHeader*(value: string): bool =
   if strVal != "" and strVal[0] == '0' and strVal[1] in {'x', 'X'} and strVal.len > 2: true
   else: false
 
-template isHexChar*(c: char): bool =
+template hasHexHeader*(value: HexDataStr|HexQuantityStr): bool =
+  value.string.hasHexHeader
+
+func isHexChar*(c: char): bool =
   if  c notin {'0'..'9'} and
       c notin {'a'..'f'} and
       c notin {'A'..'F'}: false