Add ERC20 InInstruction test

processor/ethereum/deployer/src/lib.rs

@@ -52,7 +52,7 @@ impl Deployer {
   /// funded for this transaction to be submitted. This account has no known private key to anyone
   /// so ETH sent can be neither misappropriated nor returned.
   pub fn deployment_tx() -> Signed<TxLegacy> {
-    let bytecode = Bytes::from(BYTECODE);
+    let bytecode = Bytes::from_static(BYTECODE);
 
     // Legacy transactions are used to ensure the widest possible degree of support across EVMs
     let tx = TxLegacy {

processor/ethereum/router/build.rs

@@ -41,6 +41,9 @@ fn main() {
       "contracts/IRouter.sol",
       "contracts/Router.sol",
     ],
-    &(artifacts_path + "/router.rs"),
+    &(artifacts_path.clone() + "/router.rs"),
   );
+
+  // Build the test contracts
+  build_solidity_contracts::build(&[], "contracts/tests", &(artifacts_path + "/tests")).unwrap();
 }

processor/ethereum/router/contracts/tests/ERC20.sol

@@ -17,17 +17,11 @@ contract TestERC20 {
     return 18;
   }
 
-  function totalSupply() public pure returns (uint256) {
-    return 1_000_000 * 10e18;
-  }
+  uint256 public totalSupply;
 
   mapping(address => uint256) balances;
   mapping(address => mapping(address => uint256)) allowances;
 
-  constructor() {
-    balances[msg.sender] = totalSupply();
-  }
-
   function balanceOf(address owner) public view returns (uint256) {
     return balances[owner];
   }
@@ -35,6 +29,7 @@ contract TestERC20 {
   function transfer(address to, uint256 value) public returns (bool) {
     balances[msg.sender] -= value;
     balances[to] += value;
+    emit Transfer(msg.sender, to, value);
     return true;
   }
 
@@ -42,15 +37,28 @@ contract TestERC20 {
     allowances[from][msg.sender] -= value;
     balances[from] -= value;
     balances[to] += value;
+    emit Transfer(from, to, value);
     return true;
   }
 
   function approve(address spender, uint256 value) public returns (bool) {
     allowances[msg.sender][spender] = value;
+    emit Approval(msg.sender, spender, value);
     return true;
   }
 
   function allowance(address owner, address spender) public view returns (uint256) {
     return allowances[owner][spender];
   }
+
+  function mint(address owner, uint256 value) external {
+    balances[owner] += value;
+    totalSupply += value;
+    emit Transfer(address(0), owner, value);
+  }
+
+  function magicApprove(address owner, address spender, uint256 value) external {
+    allowances[owner][spender] = value;
+    emit Approval(owner, spender, value);
+  }
 }

processor/ethereum/router/src/lib.rs

@@ -11,10 +11,7 @@ use borsh::{BorshSerialize, BorshDeserialize};
 
 use group::ff::PrimeField;
 
-use alloy_core::primitives::{
-  hex::{self, FromHex},
-  Address, U256, Bytes, TxKind,
-};
+use alloy_core::primitives::{hex, Address, U256, TxKind};
 use alloy_sol_types::{SolValue, SolConstructor, SolCall, SolEvent};
 
 use alloy_consensus::TxLegacy;
@@ -257,9 +254,18 @@ impl Router {
   const ESCAPE_HATCH_GAS: u64 = 61_238;
 
   fn code() -> Vec<u8> {
-    const BYTECODE: &[u8] =
-      include_bytes!(concat!(env!("OUT_DIR"), "/serai-processor-ethereum-router/Router.bin"));
-    Bytes::from_hex(BYTECODE).expect("compiled-in Router bytecode wasn't valid hex").to_vec()
+    const BYTECODE: &[u8] = {
+      const BYTECODE_HEX: &[u8] =
+        include_bytes!(concat!(env!("OUT_DIR"), "/serai-processor-ethereum-router/Router.bin"));
+      const BYTECODE: [u8; BYTECODE_HEX.len() / 2] =
+        match hex::const_decode_to_array::<{ BYTECODE_HEX.len() / 2 }>(BYTECODE_HEX) {
+          Ok(bytecode) => bytecode,
+          Err(_) => panic!("Router.bin did not contain valid hex"),
+        };
+      &BYTECODE
+    };
+
+    BYTECODE.to_vec()
   }
 
   fn init_code(key: &PublicKey) -> Vec<u8> {

processor/ethereum/router/src/tests/erc20.rs

@@ -0,0 +1,83 @@
+use alloy_core::primitives::{hex, Address, U256, Bytes, TxKind, PrimitiveSignature};
+use alloy_sol_types::SolCall;
+
+use alloy_consensus::{TxLegacy, SignableTransaction, Signed};
+
+use alloy_provider::Provider;
+
+use ethereum_primitives::keccak256;
+
+use crate::tests::Test;
+
+#[rustfmt::skip]
+#[expect(warnings)]
+#[expect(needless_pass_by_value)]
+#[expect(clippy::all)]
+#[expect(clippy::ignored_unit_patterns)]
+#[expect(clippy::redundant_closure_for_method_calls)]
+mod abi {
+  alloy_sol_macro::sol!("contracts/tests/ERC20.sol");
+}
+
+pub struct Erc20(Address);
+impl Erc20 {
+  pub(crate) async fn deploy(test: &Test) -> Self {
+    const BYTECODE: &[u8] = {
+      const BYTECODE_HEX: &[u8] =
+        include_bytes!(concat!(env!("OUT_DIR"), "/serai-processor-ethereum-router/TestERC20.bin"));
+      const BYTECODE: [u8; BYTECODE_HEX.len() / 2] =
+        match hex::const_decode_to_array::<{ BYTECODE_HEX.len() / 2 }>(BYTECODE_HEX) {
+          Ok(bytecode) => bytecode,
+          Err(_) => panic!("TestERC20.bin did not contain valid hex"),
+        };
+      &BYTECODE
+    };
+
+    let tx = TxLegacy {
+      chain_id: None,
+      nonce: 0,
+      gas_price: 100_000_000_000u128,
+      gas_limit: 1_000_000,
+      to: TxKind::Create,
+      value: U256::ZERO,
+      input: Bytes::from_static(BYTECODE),
+    };
+    let tx = ethereum_primitives::deterministically_sign(tx);
+    let receipt = ethereum_test_primitives::publish_tx(&test.provider, tx).await;
+    Self(receipt.contract_address.unwrap())
+  }
+
+  pub(crate) fn address(&self) -> Address {
+    self.0
+  }
+
+  pub(crate) async fn approve(&self, test: &Test, owner: Address, spender: Address, amount: U256) {
+    let tx = TxLegacy {
+      chain_id: None,
+      nonce: 0,
+      gas_price: 100_000_000_000u128,
+      gas_limit: 1_000_000,
+      to: self.0.into(),
+      value: U256::ZERO,
+      input: abi::TestERC20::magicApproveCall::new((owner, spender, amount)).abi_encode().into(),
+    };
+    let tx = ethereum_primitives::deterministically_sign(tx);
+    let receipt = ethereum_test_primitives::publish_tx(&test.provider, tx).await;
+    assert!(receipt.status());
+  }
+
+  pub(crate) async fn mint(&self, test: &Test, account: Address, amount: U256) {
+    let tx = TxLegacy {
+      chain_id: None,
+      nonce: 0,
+      gas_price: 100_000_000_000u128,
+      gas_limit: 1_000_000,
+      to: self.0.into(),
+      value: U256::ZERO,
+      input: abi::TestERC20::mintCall::new((account, amount)).abi_encode().into(),
+    };
+    let tx = ethereum_primitives::deterministically_sign(tx);
+    let receipt = ethereum_test_primitives::publish_tx(&test.provider, tx).await;
+    assert!(receipt.status());
+  }
+}

processor/ethereum/router/src/tests/mod.rs

@@ -38,6 +38,8 @@ use crate::{
 };
 
 mod constants;
+mod erc20;
+use erc20::Erc20;
 
 pub(crate) fn test_key() -> (Scalar, PublicKey) {
   loop {
@@ -241,13 +243,17 @@ impl Test {
     self.verify_state().await;
   }
 
+  fn in_instruction() -> Shorthand {
+    Shorthand::Raw(RefundableInInstruction {
+      origin: None,
+      instruction: SeraiInInstruction::Transfer(SeraiAddress([0xff; 32])),
+    })
+  }
+
   fn eth_in_instruction_tx(&self) -> (Coin, U256, Shorthand, TxLegacy) {
     let coin = Coin::Ether;
     let amount = U256::from(1);
-    let shorthand = Shorthand::Raw(RefundableInInstruction {
-      origin: None,
-      instruction: SeraiInInstruction::Transfer(SeraiAddress([0xff; 32])),
-    });
+    let shorthand = Self::in_instruction();
 
     let mut tx = self.router.in_instruction(coin, amount, &shorthand);
     tx.gas_limit = 1_000_000;
@@ -363,7 +369,74 @@ async fn test_eth_in_instruction() {
 
 #[tokio::test]
 async fn test_erc20_in_instruction() {
-  todo!("TODO")
+  let mut test = Test::new().await;
+  test.confirm_next_serai_key().await;
+
+  let erc20 = Erc20::deploy(&test).await;
+
+  let coin = Coin::Erc20(erc20.address());
+  let amount = U256::from(1);
+  let shorthand = Test::in_instruction();
+
+  // The provided `in_instruction` function will use a top-level transfer for ERC20 InInstructions,
+  // so we have to manually write this call
+  let tx = TxLegacy {
+    chain_id: None,
+    nonce: 0,
+    gas_price: 100_000_000_000u128,
+    gas_limit: 1_000_000,
+    to: test.router.address().into(),
+    value: U256::ZERO,
+    input: crate::abi::inInstructionCall::new((coin.into(), amount, shorthand.encode().into()))
+      .abi_encode()
+      .into(),
+  };
+
+  // If no `approve` was granted, this should fail
+  assert!(matches!(
+    test.call_and_decode_err(tx.clone()).await,
+    IRouterErrors::TransferFromFailed(IRouter::TransferFromFailed {})
+  ));
+
+  let tx = ethereum_primitives::deterministically_sign(tx);
+  {
+    let signer = tx.recover_signer().unwrap();
+    erc20.mint(&test, signer, amount).await;
+    erc20.approve(&test, signer, test.router.address(), amount).await;
+  }
+  let receipt = ethereum_test_primitives::publish_tx(&test.provider, tx.clone()).await;
+  assert!(receipt.status());
+
+  let block = receipt.block_number.unwrap();
+
+  // If we don't whitelist this token, we shouldn't be yielded an InInstruction
+  {
+    let in_instructions =
+      test.router.in_instructions_unordered(block, block, &HashSet::new()).await.unwrap();
+    assert!(in_instructions.is_empty());
+  }
+
+  let in_instructions = test
+    .router
+    .in_instructions_unordered(block, block, &HashSet::from([coin.into()]))
+    .await
+    .unwrap();
+  assert_eq!(in_instructions.len(), 1);
+  assert_eq!(
+    in_instructions[0],
+    InInstruction {
+      id: LogIndex {
+        block_hash: *receipt.block_hash.unwrap(),
+        // First is the Transfer log, then the InInstruction log
+        index_within_block: receipt.inner.logs()[1].log_index.unwrap(),
+      },
+      transaction_hash: **tx.hash(),
+      from: tx.recover_signer().unwrap(),
+      coin,
+      amount,
+      data: shorthand.encode(),
+    }
+  );
 }
 
 #[tokio::test]