feat: add stateless validator skelaton

crates/gateway/Cargo.toml

@@ -12,6 +12,7 @@ workspace = true
 assert_matches.workspace = true
 axum.workspace = true
 hyper.workspace = true
+rstest.workspace = true
 serde.workspace = true
 serde_json.workspace = true
 starknet_api.workspace = true

crates/gateway/src/errors.rs

@@ -19,3 +19,9 @@ pub enum GatewayConfigError {
     #[error("Server address is not an bind IP address: {0}")]
     InvalidServerBindAddress(String),
 }
+
+#[derive(Debug, Error)]
+#[cfg_attr(test, derive(PartialEq))]
+pub enum TransactionValidatorError {}
+
+pub type TransactionValidatorResult<T> = Result<T, TransactionValidatorError>;

crates/gateway/src/lib.rs

@@ -1,2 +1,4 @@
 pub mod errors;
 pub mod gateway;
+pub mod starknet_api_utils;
+pub mod transaction_validator;

crates/gateway/src/starknet_api_utils.rs

@@ -0,0 +1,74 @@
+use starknet_api::external_transaction::{
+    DataAvailabilityMode, ExternalDeclareTransaction, ExternalDeclareTransactionV3,
+    ExternalDeployAccountTransaction, ExternalDeployAccountTransactionV3,
+    ExternalInvokeTransaction, ExternalInvokeTransactionV3, ExternalTransaction,
+};
+use starknet_api::transaction::{ResourceBounds, ResourceBoundsMapping, TransactionVersion};
+
+// Utils.
+pub fn create_external_declare_tx_for_testing() -> ExternalTransaction {
+    ExternalTransaction::Declare(ExternalDeclareTransaction::V3(
+        ExternalDeclareTransactionV3 {
+            resource_bounds: zero_resource_bounds_mapping(),
+            contract_class: Default::default(),
+            tip: Default::default(),
+            signature: Default::default(),
+            nonce: Default::default(),
+            compiled_class_hash: Default::default(),
+            sender_address: Default::default(),
+            nonce_data_availability_mode: DataAvailabilityMode::L1,
+            fee_data_availability_mode: DataAvailabilityMode::L1,
+            paymaster_data: Default::default(),
+            account_deployment_data: Default::default(),
+            version: TransactionVersion::THREE,
+        },
+    ))
+}
+
+pub fn create_external_deploy_account_tx_for_testing() -> ExternalTransaction {
+    ExternalTransaction::DeployAccount(ExternalDeployAccountTransaction::V3(
+        ExternalDeployAccountTransactionV3 {
+            resource_bounds: zero_resource_bounds_mapping(),
+            tip: Default::default(),
+            contract_address_salt: Default::default(),
+            class_hash: Default::default(),
+            constructor_calldata: Default::default(),
+            nonce: Default::default(),
+            signature: Default::default(),
+            nonce_data_availability_mode: DataAvailabilityMode::L1,
+            fee_data_availability_mode: DataAvailabilityMode::L1,
+            paymaster_data: Default::default(),
+            version: TransactionVersion::THREE,
+        },
+    ))
+}
+
+pub fn create_external_invoke_tx_for_testing() -> ExternalTransaction {
+    ExternalTransaction::Invoke(ExternalInvokeTransaction::V3(ExternalInvokeTransactionV3 {
+        resource_bounds: zero_resource_bounds_mapping(),
+        tip: Default::default(),
+        signature: Default::default(),
+        nonce: Default::default(),
+        sender_address: Default::default(),
+        calldata: Default::default(),
+        nonce_data_availability_mode: DataAvailabilityMode::L1,
+        fee_data_availability_mode: DataAvailabilityMode::L1,
+        paymaster_data: Default::default(),
+        account_deployment_data: Default::default(),
+        version: TransactionVersion::THREE,
+    }))
+}
+
+pub fn zero_resource_bounds_mapping() -> ResourceBoundsMapping {
+    ResourceBoundsMapping::try_from(vec![
+        (
+            starknet_api::transaction::Resource::L1Gas,
+            ResourceBounds::default(),
+        ),
+        (
+            starknet_api::transaction::Resource::L2Gas,
+            ResourceBounds::default(),
+        ),
+    ])
+    .expect("Resource bounds mapping has unexpected structure.")
+}

crates/gateway/src/transaction_validator.rs

@@ -0,0 +1,24 @@
+use starknet_api::external_transaction::ExternalTransaction;
+
+use crate::errors::TransactionValidatorResult;
+
+#[cfg(test)]
+#[path = "transaction_validator_test.rs"]
+mod transaction_validator_test;
+
+pub struct TransactionValidatorConfig {}
+
+pub struct TransactionValidator {
+    pub config: TransactionValidatorConfig,
+}
+
+impl TransactionValidator {
+    pub fn validate(&self, _tx: ExternalTransaction) -> TransactionValidatorResult<()> {
+        // TODO(Arni, 1/5/2024): Add a mechanism that validate the sender address is not blocked.
+        // TODO(Arni, 1/5/2024): Validate transaction version.
+        // TODO(Arni, 4/4/2024): Validate fee non zero.
+        // TODO(Arni, 4/4/2024): Validate tx signature and calldata are not too long.
+
+        Ok(())
+    }
+}

crates/gateway/src/transaction_validator_test.rs

@@ -0,0 +1,40 @@
+use rstest::rstest;
+
+use starknet_api::external_transaction::ExternalTransaction;
+
+use crate::starknet_api_utils::{
+    create_external_declare_tx_for_testing, create_external_deploy_account_tx_for_testing,
+    create_external_invoke_tx_for_testing,
+};
+use crate::transaction_validator::{
+    TransactionValidator, TransactionValidatorConfig, TransactionValidatorResult,
+};
+
+const VALIDATOR_CONFIG_FOR_TESTING: TransactionValidatorConfig = TransactionValidatorConfig {};
+
+#[rstest]
+#[case::valid_declare_tx(
+    VALIDATOR_CONFIG_FOR_TESTING,
+    create_external_declare_tx_for_testing(),
+    Ok(())
+)]
+#[case::valid_deploy_account_tx(
+    VALIDATOR_CONFIG_FOR_TESTING,
+    create_external_deploy_account_tx_for_testing(),
+    Ok(())
+)]
+#[case::valid_invoke_tx(
+    VALIDATOR_CONFIG_FOR_TESTING,
+    create_external_invoke_tx_for_testing(),
+    Ok(())
+)]
+fn test_transaction_validator(
+    #[case] config: TransactionValidatorConfig,
+    #[case] tx: ExternalTransaction,
+    #[case] expected_result: TransactionValidatorResult<()>,
+) {
+    let tx_validator = TransactionValidator { config };
+    let result = tx_validator.validate(tx);
+
+    assert_eq!(result, expected_result);
+}