From 2f75f2c518350b4b39bc51d402489ec8dd2de2dc Mon Sep 17 00:00:00 2001
From: James Prestwich <james@prestwi.ch>
Date: Wed, 30 Oct 2024 07:25:10 -0400
Subject: [PATCH] feat: add has_eip155_value convenience function to signature
 (#791)

---
 crates/primitives/src/signature/parity.rs | 15 ++++++++++++++-
 crates/primitives/src/signature/sig.rs    | 19 +++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/crates/primitives/src/signature/parity.rs b/crates/primitives/src/signature/parity.rs
index 1fc44cf35..b16011b0d 100644
--- a/crates/primitives/src/signature/parity.rs
+++ b/crates/primitives/src/signature/parity.rs
@@ -62,7 +62,10 @@ impl TryFrom<u64> for Parity {
 }
 
 impl Parity {
-    /// Get the chain_id of the V value, if any.
+    /// Returns the chain ID associated with the V value, if this signature is
+    /// replay-protected by [EIP-155].
+    ///
+    /// [EIP-155]: https://eips.ethereum.org/EIPS/eip-155
     pub const fn chain_id(&self) -> Option<ChainId> {
         match *self {
             Self::Eip155(mut v @ 35..) => {
@@ -76,6 +79,16 @@ impl Parity {
         }
     }
 
+    /// Returns true if the signature is replay-protected by [EIP-155].
+    ///
+    /// This is true if the V value is 35 or greater. Values less than 35 are
+    /// either not replay protected (27/28), or are invalid.
+    ///
+    /// [EIP-155]: https://eips.ethereum.org/EIPS/eip-155
+    pub const fn has_eip155_value(&self) -> bool {
+        self.chain_id().is_some()
+    }
+
     /// Return the y-parity as a boolean.
     pub const fn y_parity(&self) -> bool {
         match self {
diff --git a/crates/primitives/src/signature/sig.rs b/crates/primitives/src/signature/sig.rs
index d2de0ad66..f121c4730 100644
--- a/crates/primitives/src/signature/sig.rs
+++ b/crates/primitives/src/signature/sig.rs
@@ -301,6 +301,25 @@ impl Signature {
         self.v
     }
 
+    /// Returns the chain ID associated with the V value, if this signature is
+    /// replay-protected by [EIP-155].
+    ///
+    /// [EIP-155]: https://eips.ethereum.org/EIPS/eip-155
+    pub const fn chain_id(&self) -> Option<u64> {
+        self.v.chain_id()
+    }
+
+    /// Returns true if the signature is replay-protected by [EIP-155].
+    ///
+    /// This is true if the V value is 35 or greater. Values less than 35 are
+    /// either not replay protected (27/28), or are invalid.
+    ///
+    /// [EIP-155]: https://eips.ethereum.org/EIPS/eip-155
+    #[inline]
+    pub const fn has_eip155_value(&self) -> bool {
+        self.v().has_eip155_value()
+    }
+
     /// Returns the byte-array representation of this signature.
     ///
     /// The first 32 bytes are the `r` value, the second 32 bytes the `s` value