From a100fb3e46cb5f40d6580ece884effacae37b0c7 Mon Sep 17 00:00:00 2001
From: DoTheBestToGetTheBest
 <146037313+DoTheBestToGetTheBest@users.noreply.github.com>
Date: Sun, 12 Nov 2023 04:10:00 -0800
Subject: [PATCH] feat(bin) : refactor ZeroAsNone struct to a Macro  (#5397)

Co-authored-by: Matthias Seitz <matthias.seitz@outlook.de>
---
 bin/reth/src/args/rpc_server_args.rs | 10 ++--
 bin/reth/src/args/types.rs           | 69 ++++++++++++++++------------
 bin/reth/src/cli/mod.rs              |  2 +-
 3 files changed, 46 insertions(+), 35 deletions(-)

diff --git a/bin/reth/src/args/rpc_server_args.rs b/bin/reth/src/args/rpc_server_args.rs
index 66937d153e..0a1ec745cb 100644
--- a/bin/reth/src/args/rpc_server_args.rs
+++ b/bin/reth/src/args/rpc_server_args.rs
@@ -2,7 +2,7 @@
 
 use crate::{
     args::{
-        types::{MaxU32, ZeroAsNone},
+        types::{MaxU32, ZeroAsNoneU64},
         GasPriceOracleArgs,
     },
     cli::{
@@ -157,12 +157,12 @@ pub struct RpcServerArgs {
     pub rpc_max_tracing_requests: u32,
 
     /// Maximum number of blocks that could be scanned per filter request. (0 = entire chain)
-    #[arg(long, value_name = "COUNT", default_value_t = ZeroAsNone::new(constants::DEFAULT_MAX_BLOCKS_PER_FILTER))]
-    pub rpc_max_blocks_per_filter: ZeroAsNone,
+    #[arg(long, value_name = "COUNT", default_value_t = ZeroAsNoneU64::new(constants::DEFAULT_MAX_BLOCKS_PER_FILTER))]
+    pub rpc_max_blocks_per_filter: ZeroAsNoneU64,
 
     /// Maximum number of logs that can be returned in a single response. (0 = no limit)
-    #[arg(long, value_name = "COUNT", default_value_t = ZeroAsNone::new(constants::DEFAULT_MAX_LOGS_PER_RESPONSE as u64))]
-    pub rpc_max_logs_per_response: ZeroAsNone,
+    #[arg(long, value_name = "COUNT", default_value_t = ZeroAsNoneU64::new(constants::DEFAULT_MAX_LOGS_PER_RESPONSE as u64))]
+    pub rpc_max_logs_per_response: ZeroAsNoneU64,
 
     /// Maximum gas limit for `eth_call` and call tracing RPC methods.
     #[arg(
diff --git a/bin/reth/src/args/types.rs b/bin/reth/src/args/types.rs
index 3dcd8f55d4..4696e5b323 100644
--- a/bin/reth/src/args/types.rs
+++ b/bin/reth/src/args/types.rs
@@ -2,40 +2,50 @@
 
 use std::{fmt, num::ParseIntError, str::FromStr};
 
-/// A helper type that maps `0` to `None` when parsing CLI arguments.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub struct ZeroAsNone(pub Option<u64>);
+/// A macro that generates types that maps "0" to "None" when parsing CLI arguments.
 
-impl ZeroAsNone {
-    /// Returns the inner value.
-    pub const fn new(value: u64) -> Self {
-        Self(Some(value))
-    }
+macro_rules! zero_as_none {
+    ($type_name:ident, $inner_type:ty) => {
+        #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+        /// A helper type that maps `0` to `None` when parsing CLI arguments.
+        pub struct $type_name(pub Option<$inner_type>);
 
-    /// Returns the inner value or `u64::MAX` if `None`.
-    pub fn unwrap_or_max(self) -> u64 {
-        self.0.unwrap_or(u64::MAX)
-    }
-}
+        impl $type_name {
+            /// Returns the inner value.
+            pub const fn new(value: $inner_type) -> Self {
+                Self(Some(value))
+            }
 
-impl fmt::Display for ZeroAsNone {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.0 {
-            Some(value) => write!(f, "{}", value),
-            None => write!(f, "0"),
+            /// Returns the inner value or `$inner_type::MAX` if `None`.
+            pub fn unwrap_or_max(self) -> $inner_type {
+                self.0.unwrap_or(<$inner_type>::MAX)
+            }
         }
-    }
+
+        impl std::fmt::Display for $type_name {
+            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+                match self.0 {
+                    Some(value) => write!(f, "{}", value),
+                    None => write!(f, "0"),
+                }
+            }
+        }
+
+        impl std::str::FromStr for $type_name {
+            type Err = std::num::ParseIntError;
+
+            fn from_str(s: &str) -> Result<Self, Self::Err> {
+                let value = s.parse::<$inner_type>()?;
+                Ok(Self(if value == 0 { None } else { Some(value) }))
+            }
+        }
+    };
 }
 
-impl FromStr for ZeroAsNone {
-    type Err = std::num::ParseIntError;
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        let value = s.parse::<u64>()?;
-        Ok(Self(if value == 0 { None } else { Some(value) }))
-    }
-}
+zero_as_none!(ZeroAsNoneU64, u64);
+zero_as_none!(ZeroAsNoneU32, u32);
 
+/// A macro that generates types that map "max" to "MAX" when parsing CLI arguments.
 macro_rules! max_values {
     ($name:ident, $ty:ident) => {
         #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -78,14 +88,15 @@ macro_rules! max_values {
 }
 max_values!(MaxU32, u32);
 max_values!(MaxU64, u64);
+
 #[cfg(test)]
 mod tests {
     use super::*;
 
     #[test]
     fn test_zero_parse() {
-        let val = "0".parse::<ZeroAsNone>().unwrap();
-        assert_eq!(val, ZeroAsNone(None));
+        let val = "0".parse::<ZeroAsNoneU64>().unwrap();
+        assert_eq!(val, ZeroAsNoneU64(None));
         assert_eq!(val.unwrap_or_max(), u64::MAX);
     }
 }
diff --git a/bin/reth/src/cli/mod.rs b/bin/reth/src/cli/mod.rs
index d48afb627c..1361b53d2d 100644
--- a/bin/reth/src/cli/mod.rs
+++ b/bin/reth/src/cli/mod.rs
@@ -363,7 +363,7 @@ mod tests {
         let end = format!("reth/logs/{}", SUPPORTED_CHAINS[0]);
         assert!(log_dir.as_ref().ends_with(end), "{:?}", log_dir);
 
-        let mut iter = SUPPORTED_CHAINS.into_iter();
+        let mut iter = SUPPORTED_CHAINS.iter();
         iter.next();
         for chain in iter {
             let mut reth = Cli::<()>::try_parse_from(["reth", "node", "--chain", chain]).unwrap();