fix: remove `OpCode` enum and update `VMOperation`'s `op` field type (#1904)

* remove OpCode enum and update VMOperation's op field

* restore opcodes + update 0x20 to keccak256

* enum to deserialize opcodes into known or unknown

* Update ethers-core/src/types/trace/mod.rs

Co-authored-by: Georgios Konstantopoulos <me@gakonst.com>

* fix typo: ExecutedInstruction

Co-authored-by: Georgios Konstantopoulos <me@gakonst.com>

ethers-core/src/types/trace/mod.rs

@@ -134,9 +134,9 @@ pub struct VMOperation {
     /// Subordinate trace of the CALL/CREATE if applicable.
     // #[serde(bound="VMTrace: Deserialize")]
     pub sub: Option<VMTrace>,
-    /// The executed opcode name
+    /// The opcode of the executed instruction
     #[serde(rename = "op")]
-    pub op: OpCode,
+    pub op: ExecutedInstruction,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Default, Deserialize, Serialize)]
@@ -176,6 +176,23 @@ pub struct StorageDiff {
     pub val: U256,
 }
 
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(untagged)]
+#[allow(clippy::upper_case_acronyms)]
+/// Helper to classify the executed instruction
+pub enum ExecutedInstruction {
+    /// The instruction is recognized
+    Known(Opcode),
+    /// The instruction is not recognized
+    Unknown(String),
+}
+
+impl Default for ExecutedInstruction {
+    fn default() -> Self {
+        Self::Known(Opcode::INVALID)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -208,4 +225,19 @@ mod tests {
     fn test_deserialize_blocktraces() {
         let _traces: Vec<BlockTrace> = serde_json::from_str(EXAMPLE_TRACES).unwrap();
     }
+
+    #[test]
+    fn test_deserialize_unknown_opcode() {
+        let example_opcodes = r#"["GAS", "CREATE2", "CUSTOMOP"]"#;
+        let parsed_opcodes: Vec<ExecutedInstruction> =
+            serde_json::from_str(example_opcodes).unwrap();
+        assert_eq!(
+            vec![
+                ExecutedInstruction::Known(Opcode::GAS),
+                ExecutedInstruction::Known(Opcode::CREATE2),
+                ExecutedInstruction::Unknown("CUSTOMOP".to_string())
+            ],
+            parsed_opcodes
+        )
+    }
 }

ethers-core/src/types/trace/opcodes.rs

@@ -2,9 +2,9 @@ use serde::{Deserialize, Serialize};
 
 // opcode descriptions taken from evm.codes https://github.com/comitylabs/evm.codes/blob/bc7f102808055d88365559d40c190c5bd6d164c3/opcodes.json
 // https://github.com/ethereum/go-ethereum/blob/2b1299b1c006077c56ecbad32e79fc16febe3dd6/core/vm/opcodes.go
-#[derive(Debug, Clone, PartialEq, Eq, Default, Deserialize, Serialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize, Serialize)]
 /// Name of executed EVM opcode
-pub enum OpCode {
+pub enum Opcode {
     // 0x0 range - arithmetic ops.
     /// Opcode 0x0 - Halts execution
     STOP,
@@ -67,7 +67,7 @@ pub enum OpCode {
 
     // 0x20 range - crypto.
     /// Opcode 0x20 - Compute Keccak-256 hash
-    SHA3,
+    KECCAK256,
 
     // 0x21 - 0x2F are invalid
 
@@ -335,7 +335,6 @@ pub enum OpCode {
     // 0xfd range - closures
     /// Opcode 0xFD - Halt execution reverting state changes but returning data and remaining gas
     REVERT,
-    #[default]
     /// Opcode 0xFE - Designated invalid instruction
     INVALID,
     /// Opcode 0xFF - Halt execution and register account for later deletion