feat: gas service (#3)

* feat: add workspace for axelar gas service * feat: add refund impl and set up tests * feat: add impl for pay_native_gas_for_contract_call * feat: implement collect_fees chore: add back contract_id as output to the setup_emv test chore: update tests to pass in correct token address into refund chore: WIP - adding auth for refund methods and tests for emitted events chore: unwrapping index value * feat: update gas service unit tests * chore: remove vec from and add emitted event to collect_fees api * chore: cargo fmt * Update contracts/axelar-gas-service/Cargo.toml Co-authored-by: Milap Sheth <[email protected]> * Update contracts/axelar-gas-service/Cargo.toml Co-authored-by: Milap Sheth <[email protected]> * Update contracts/axelar-gas-service/src/contract.rs Co-authored-by: Milap Sheth <[email protected]> * Update contracts/axelar-gas-service/src/test.rs Co-authored-by: Milap Sheth <[email protected]> * Update contracts/axelar-gas-service/src/error.rs Co-authored-by: Milap Sheth <[email protected]> * Update contracts/axelar-gas-service/src/event.rs Co-authored-by: Milap Sheth <[email protected]> * Update contracts/axelar-gas-service/src/event.rs Co-authored-by: Milap Sheth <[email protected]> * Update contracts/axelar-gas-service/src/event.rs Co-authored-by: Milap Sheth <[email protected]> * Update contracts/axelar-gas-service/src/event.rs Co-authored-by: Milap Sheth <[email protected]> * Update contracts/axelar-gas-service/src/interface.rs Co-authored-by: Milap Sheth <[email protected]> * Update contracts/axelar-gas-service/src/lib.rs Co-authored-by: Milap Sheth <[email protected]> * chore: addressing latest comments on gas-service PR * chore: fmt code chore: fmt code chore: run cargo sort * chore: reduce parameter list size in pay_gas_for_contract_call * Update contracts/axelar-soroban-interfaces/src/axelar_gas_service.rs Co-authored-by: Milap Sheth <[email protected]> * Update contracts/axelar-soroban-interfaces/src/axelar_gas_service.rs Co-authored-by: Milap Sheth <[email protected]> * Update contracts/axelar-gas-service/src/contract.rs Co-authored-by: Milap Sheth <[email protected]> * Update contracts/axelar-soroban-interfaces/src/axelar_gas_service.rs Co-authored-by: Milap Sheth <[email protected]> * Update contracts/axelar-gas-service/src/contract.rs Co-authored-by: Milap Sheth <[email protected]> * Update packages/axelar-soroban-std/src/types.rs Co-authored-by: Milap Sheth <[email protected]> * Update contracts/axelar-soroban-interfaces/src/axelar_gas_service.rs Co-authored-by: Milap Sheth <[email protected]> * chore: refactor gas service chore: incorporate add'l comments * chore: update pay_gas_for_contract_call to use tranfer_from * Update contracts/axelar-gas-service/src/event.rs Co-authored-by: Milap Sheth <[email protected]> * Update contracts/axelar-gas-service/src/contract.rs Co-authored-by: Milap Sheth <[email protected]> * Update contracts/axelar-gas-service/src/contract.rs Co-authored-by: Milap Sheth <[email protected]> * Update contracts/axelar-gas-service/src/test.rs Co-authored-by: Milap Sheth <[email protected]> * Update contracts/axelar-gas-service/src/test.rs Co-authored-by: Milap Sheth <[email protected]> * chore: fix tests with variable name change --------- Co-authored-by: Milap Sheth <[email protected]> Co-authored-by: Milap Sheth <[email protected]>
axelarnetwork · Mar 19, 2024 · 64fdccf · 64fdccf
1 parent 65a0891
commit 64fdccf
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diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -14,6 +14,7 @@ soroban-sdk = { version = "20.2.0" }
 axelar-soroban-interfaces = { version = "^0.1.0", path = "contracts/axelar-soroban-interfaces" }
 axelar-soroban-std = { version = "^0.1.0", path = "packages/axelar-soroban-std" }
 axelar-auth-verifier = { version = "^0.1.0", path = "contracts/axelar-auth-verifier" }
+axelar-gas-service = { version = "^0.1.0", path = "contracts/axelar-gas-service" }
 axelar-gateway = { version = "^0.1.0", path = "contracts/axelar-gateway" }
 
 [profile.release]

diff --git a/contracts/axelar-gas-service/Cargo.toml b/contracts/axelar-gas-service/Cargo.toml
@@ -0,0 +1,16 @@
+[package]
+name = "axelar-gas-service"
+version = "0.1.0"
+edition = { workspace = true }
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+axelar-soroban-interfaces = { workspace = true }
+axelar-soroban-std = { workspace = true }
+soroban-sdk = { workspace = true }
+
+[dev_dependencies]
+soroban-sdk = { workspace = true, features = ["testutils"] }
+axelar-soroban-std = { workspace = true, features = ["testutils"] }
diff --git a/contracts/axelar-gas-service/src/contract.rs b/contracts/axelar-gas-service/src/contract.rs
@@ -0,0 +1,107 @@
+use soroban_sdk::{contract, contractimpl, panic_with_error, token, Address, Bytes, Env, String};
+
+use axelar_soroban_std::types::Token;
+
+use crate::storage_types::DataKey;
+use crate::{error::Error, event};
+use axelar_soroban_interfaces::axelar_gas_service::AxelarGasServiceInterface;
+
+#[contract]
+pub struct AxelarGasService;
+
+#[contractimpl]
+impl AxelarGasServiceInterface for AxelarGasService {
+    fn initialize(env: Env, gas_collector: Address) {
+        if env
+            .storage()
+            .instance()
+            .get(&DataKey::Initialized)
+            .unwrap_or(false)
+        {
+            panic!("Already initialized");
+        }
+
+        env.storage().instance().set(&DataKey::Initialized, &true);
+
+        env.storage()
+            .instance()
+            .set(&DataKey::GasCollector, &gas_collector);
+    }
+
+    fn pay_gas_for_contract_call(
+        env: Env,
+        sender: Address,
+        destination_chain: String,
+        destination_address: String,
+        payload: Bytes,
+        refund_address: Address,
+        token: Token,
+    ) {
+        sender.require_auth();
+
+        if token.amount <= 0 {
+            panic_with_error!(env, Error::InvalidAmount);
+        }
+
+        token::Client::new(&env, &token.address).transfer_from(
+            &env.current_contract_address(),
+            &sender,
+            &env.current_contract_address(),
+            &token.amount,
+        );
+
+        event::gas_paid_for_contract_call(
+            &env,
+            sender,
+            destination_chain,
+            destination_address,
+            payload,
+            refund_address,
+            token,
+        );
+    }
+
+    fn collect_fees(env: Env, receiver: Address, token: Token) {
+        let gas_collector: Address = env
+            .storage()
+            .instance()
+            .get(&DataKey::GasCollector)
+            .unwrap();
+
+        gas_collector.require_auth();
+
+        if token.amount <= 0 {
+            panic_with_error!(env, Error::InvalidAmount);
+        }
+
+        let token_client = token::Client::new(&env, &token.address);
+
+        let contract_token_balance = token_client.balance(&env.current_contract_address());
+
+        if contract_token_balance >= token.amount {
+            token_client.transfer(&env.current_contract_address(), &receiver, &token.amount)
+        } else {
+            panic_with_error!(env, Error::InsufficientBalance);
+        }
+
+        event::fee_collected(&env, gas_collector, token);
+    }
+
+    fn refund(env: Env, message_id: String, receiver: Address, token: Token) {
+        let gas_collector: Address = env
+            .storage()
+            .instance()
+            .get(&DataKey::GasCollector)
+            .unwrap();
+
+        gas_collector.require_auth();
+
+        token::Client::new(&env, &token.address).transfer(
+            &env.current_contract_address(),
+            &receiver,
+            &token.amount,
+        );
+
+        event::refunded(&env, message_id, receiver, token);
+    }
+}
diff --git a/contracts/axelar-gas-service/src/error.rs b/contracts/axelar-gas-service/src/error.rs
@@ -0,0 +1,10 @@
+use soroban_sdk::contracterror;
+
+#[contracterror]
+#[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
+#[repr(u32)]
+pub enum Error {
+    InvalidAddress = 1,
+    InvalidAmount = 2,
+    InsufficientBalance = 3,
+}
diff --git a/contracts/axelar-gas-service/src/event.rs b/contracts/axelar-gas-service/src/event.rs
@@ -0,0 +1,33 @@
+use axelar_soroban_std::types::Token;
+use soroban_sdk::{symbol_short, Address, Bytes, Env, String};
+
+pub(crate) fn gas_paid_for_contract_call(
+    env: &Env,
+    sender: Address,
+    destination_chain: String,
+    destination_address: String,
+    payload: Bytes,
+    refund_address: Address,
+    token: Token,
+) {
+    let topics = (
+        symbol_short!("gas_paid"),
+        env.crypto().keccak256(&payload),
+        sender,
+        destination_chain,
+    );
+    env.events().publish(
+        topics,
+        (destination_address, payload, refund_address, token),
+    );
+}
+
+pub(crate) fn refunded(env: &Env, message_id: String, receiver: Address, token: Token) {
+    let topics = (symbol_short!("refunded"), message_id, receiver, token);
+    env.events().publish(topics, ());
+}
+
+pub(crate) fn fee_collected(env: &Env, receiver: Address, token: Token) {
+    let topics = (symbol_short!("collected"), receiver, token);
+    env.events().publish(topics, ());
+}
diff --git a/contracts/axelar-gas-service/src/lib.rs b/contracts/axelar-gas-service/src/lib.rs
@@ -0,0 +1,11 @@
+#![no_std]
+
+pub mod contract;
+mod error;
+mod event;
+mod storage_types;
+
+#[cfg(test)]
+mod test;
+
+pub use contract::AxelarGasServiceClient;
diff --git a/contracts/axelar-gas-service/src/storage_types.rs b/contracts/axelar-gas-service/src/storage_types.rs
@@ -0,0 +1,8 @@
+use soroban_sdk::contracttype;
+
+#[contracttype]
+#[derive(Clone, Debug)]
+pub enum DataKey {
+    Initialized,
+    GasCollector,
+}
diff --git a/contracts/axelar-gas-service/src/test.rs b/contracts/axelar-gas-service/src/test.rs
@@ -0,0 +1,146 @@
+#![cfg(test)]
+extern crate std;
+
+use std::format;
+
+use axelar_soroban_std::{assert_emitted_event, types::Token};
+
+use crate::contract::{AxelarGasService, AxelarGasServiceClient};
+use soroban_sdk::{
+    bytes, symbol_short,
+    testutils::Address as _,
+    token::{StellarAssetClient, TokenClient},
+    Address, Env, String,
+};
+
+fn setup_env<'a>() -> (Env, Address, Address, AxelarGasServiceClient<'a>) {
+    let env = Env::default();
+
+    env.mock_all_auths();
+
+    let contract_id = env.register_contract(None, AxelarGasService);
+
+    let client = AxelarGasServiceClient::new(&env, &contract_id);
+    let gas_collector: Address = Address::generate(&env);
+    client.initialize(&gas_collector);
+
+    (env, contract_id, gas_collector, client)
+}
+
+#[test]
+fn pay_gas_for_contract_call() {
+    let (env, contract_id, _, client) = setup_env();
+
+    let token_address: Address = env.register_stellar_asset_contract(Address::generate(&env));
+    let sender: Address = Address::generate(&env);
+    let gas_amount: i128 = 1;
+    let token = Token {
+        address: token_address.clone(),
+        amount: gas_amount,
+    };
+    let refund_address: Address = Address::generate(&env);
+    let payload = bytes!(&env, 0x1234);
+    let destination_chain: String = String::from_str(&env, "ethereum");
+    let destination_address: String =
+        String::from_str(&env, "0x4EFE356BEDeCC817cb89B4E9b796dB8bC188DC59");
+
+    let token_client = TokenClient::new(&env, &token_address);
+    StellarAssetClient::new(&env, &token_address).mint(&sender, &gas_amount);
+
+    let expiration_ledger = &env.ledger().sequence() + 200;
+
+    // approve token spend before invoking `pay_gas_for_contract_call`
+    token_client.approve(&sender, &contract_id, &gas_amount, &expiration_ledger);
+
+    assert_eq!(token_client.allowance(&sender, &contract_id), gas_amount);
+
+    client.pay_gas_for_contract_call(
+        &sender,
+        &destination_chain,
+        &destination_address,
+        &payload,
+        &refund_address,
+        &token,
+    );
+
+    assert_eq!(0, token_client.balance(&sender));
+    assert_eq!(gas_amount, token_client.balance(&contract_id));
+    assert_eq!(token_client.allowance(&sender, &contract_id), 0);
+
+    assert_emitted_event(
+        &env,
+        -1,
+        &contract_id,
+        (
+            symbol_short!("gas_paid"),
+            env.crypto().keccak256(&payload),
+            sender,
+            destination_chain,
+        ),
+        (destination_address, payload, refund_address, token),
+    );
+}
+
+#[test]
+fn collect_fees() {
+    let (env, contract_id, gas_collector, client) = setup_env();
+    let token_address: Address = env.register_stellar_asset_contract(Address::generate(&env));
+    let token_client = TokenClient::new(&env, &token_address);
+    let supply: i128 = 1000;
+    let refund_amount = 1;
+    let token = Token {
+        address: token_address.clone(),
+        amount: refund_amount,
+    };
+    StellarAssetClient::new(&env, &token.address).mint(&contract_id, &supply);
+
+    client.collect_fees(&gas_collector, &token);
+
+    assert_eq!(refund_amount, token_client.balance(&gas_collector));
+    assert_eq!(supply - refund_amount, token_client.balance(&contract_id));
+
+    assert_emitted_event(
+        &env,
+        -1,
+        &contract_id,
+        (symbol_short!("collected"), gas_collector, token),
+        (),
+    );
+}
+
+#[test]
+fn refund() {
+    let (env, contract_id, _, client) = setup_env();
+    let token_address: Address = env.register_stellar_asset_contract(Address::generate(&env));
+    let token_client = TokenClient::new(&env, &token_address);
+    let supply: i128 = 1000;
+    StellarAssetClient::new(&env, &token_address).mint(&contract_id, &supply);
+
+    let receiver: Address = Address::generate(&env);
+    let refund_amount: i128 = 1;
+    let token = Token {
+        address: token_address.clone(),
+        amount: refund_amount,
+    };
+
+    let message_id = String::from_str(
+        &env,
+        &format!(
+            "{}-{}",
+            "0xfded3f55dec47250a52a8c0bb7038e72fa6ffaae33562f77cd2b629ef7fd424d", 0
+        ),
+    );
+
+    client.refund(&message_id, &receiver, &token);
+
+    assert_eq!(refund_amount, token_client.balance(&receiver));
+    assert_eq!(supply - refund_amount, token_client.balance(&contract_id));
+
+    assert_emitted_event(
+        &env,
+        -1,
+        &contract_id,
+        (symbol_short!("refunded"), message_id, receiver, token),
+        (),
+    );
+}
diff --git a/contracts/axelar-soroban-interfaces/src/axelar_gas_service.rs b/contracts/axelar-soroban-interfaces/src/axelar_gas_service.rs
@@ -0,0 +1,26 @@
+use axelar_soroban_std::types::Token;
+use soroban_sdk::{contractclient, Address, Bytes, Env, String};
+
+/// Interface for the Axelar Gas Service.
+#[contractclient(name = "AxelarGasServiceClient")]
+pub trait AxelarGasServiceInterface {
+    /// Initialize the gas service contract with a gas_collector address.
+    fn initialize(env: Env, gas_collector: Address);
+
+    /// Pay for gas using a token for a contract call on a destination chain. This function is called on the source chain before calling the gateway to execute a remote contract.
+    fn pay_gas_for_contract_call(
+        env: Env,
+        sender: Address,
+        destination_chain: String,
+        destination_address: String,
+        payload: Bytes,
+        refund_address: Address,
+        token: Token,
+    );
+
+    /// Allows the `gas_collector` to collect accumulated fees from the contract. Only callable by the gas_collector.
+    fn collect_fees(env: Env, receiver: Address, token: Token);
+
+    /// Refunds gas payment to the receiver in relation to a specific cross-chain transaction. Only callable by the gas_collector.
+    fn refund(env: Env, message_id: String, receiver: Address, token: Token);
+}
diff --git a/contracts/axelar-soroban-interfaces/src/lib.rs b/contracts/axelar-soroban-interfaces/src/lib.rs
@@ -2,4 +2,5 @@
 
 pub mod axelar_auth_verifier;
 pub mod axelar_executable;
+pub mod axelar_gas_service;
 pub mod axelar_gateway;