fix: zero fee in dex (#43)

* fix zero fee

* fix lint

* remove comment

Author: beer-1

crates/compiler/src/built_package.rs

@@ -77,7 +77,10 @@ impl BuiltPackage {
         new_config.architecture = None;
         new_config.generate_docs = false;
         new_config.generate_move_model = true;
-        new_config.compiler_config.known_attributes = metadata::get_all_attribute_names().clone();
+        new_config
+            .compiler_config
+            .known_attributes
+            .clone_from(metadata::get_all_attribute_names());
 
         let (mut package, model_opt) =
             new_config.compile_package_no_exit(&package_path, &mut stderr())?;

crates/compiler/src/test_package.rs

@@ -28,8 +28,10 @@ impl TestPackage {
         new_build_config.test_mode = true;
         new_build_config.generate_docs = false;
         new_build_config.generate_move_model = true;
-        new_build_config.compiler_config.known_attributes =
-            metadata::get_all_attribute_names().clone();
+        new_build_config
+            .compiler_config
+            .known_attributes
+            .clone_from(metadata::get_all_attribute_names());
 
         configure_for_unit_test();
 

crates/e2e-move-tests/src/lib.rs

@@ -1,32 +1,7 @@
 pub mod harness;
 pub mod test_utils;
 
-use anyhow::bail;
 pub use harness::*;
-use move_package::package_hooks::PackageHooks;
-use move_package::source_package::parsed_manifest::CustomDepInfo;
-use move_symbol_pool::Symbol;
 
 #[cfg(test)]
 mod tests;
-
-pub(crate) struct InitiaPackageHooks {}
-pub const UPGRADE_POLICY_CUSTOM_FIELD: &str = "upgrade_policy";
-
-impl PackageHooks for InitiaPackageHooks {
-    fn custom_package_info_fields(&self) -> Vec<String> {
-        vec![UPGRADE_POLICY_CUSTOM_FIELD.to_string()]
-    }
-
-    fn custom_dependency_key(&self) -> Option<String> {
-        Some("initia".to_string())
-    }
-
-    fn resolve_custom_dependency(
-        &self,
-        _dep_name: Symbol,
-        _info: &CustomDepInfo,
-    ) -> anyhow::Result<()> {
-        bail!("not used")
-    }
-}

crates/e2e-move-tests/src/test_utils/mock_chain.rs

@@ -391,7 +391,7 @@ impl MockStakingAPI {
         metadata: AccountAddress,
         amount: u64,
     ) -> anyhow::Result<u64> {
-        match self.validators.get(&validator.to_vec()) {
+        match self.validators.get(validator) {
             Some(ratios) => match ratios.get(&metadata) {
                 Some((s, a)) => Ok(amount * s / a),
                 None => Err(anyhow!("ratio not found")),
@@ -406,7 +406,7 @@ impl MockStakingAPI {
         metadata: AccountAddress,
         share: u64,
     ) -> anyhow::Result<u64> {
-        match self.validators.get(&validator.to_vec()) {
+        match self.validators.get(validator) {
             Some(ratios) => match ratios.get(&metadata) {
                 Some((s, a)) => Ok(share * a / s),
                 None => Err(anyhow!("ratio not found")),

libmovevm/src/move_api/bytecode.rs

@@ -32,6 +32,7 @@ pub trait Bytecode {
 
     fn address_identifier_at(&self, idx: AddressIdentifierIndex) -> &AccountAddress;
 
+    #[allow(dead_code)]
     fn find_entry_function(&self, name: &IdentStr) -> Option<MoveFunction>;
 
     fn new_move_struct_field(&self, def: &FieldDefinition) -> MoveStructField {

libmovevm/src/storage.rs

@@ -11,6 +11,7 @@ use anyhow::anyhow;
 
 /// Access to the VM's backend storage, i.e. the chain
 pub trait Storage {
+    #[allow(dead_code)]
     /// Returns Err on error.
     /// Returns Ok(None) when key does not exist.
     /// Returns Ok(Some(Vec<u8>)) when key exists.

precompile/binaries/stdlib/dex.mv

@@ -204,8 +204,12 @@ module initia_std::dex {
     /// All start_after must be provided or not
     const ESTART_AFTER: u64 = 17;
 
+    // Cannot create pair with the same coin type
     const ESAME_COIN_TYPE: u64 = 19;
 
+    /// Zero amount in the swap simulation is not allowed
+    const EZERO_AMOUNT_IN: u64 = 20;
+
     // Constants
     const MAX_LIMIT: u8 = 30;
 
@@ -1359,9 +1363,17 @@ module initia_std::dex {
         amount_in: u64,
         swap_fee_rate: Decimal128,
     ): (u64, u64) {
+        assert!(amount_in > 0, error::invalid_argument(EZERO_AMOUNT_IN));
+
         let one = decimal128::one();
         let exp = decimal128::from_ratio(decimal128::val(&weight_in), decimal128::val(&weight_out));
+
+        // avoid zero fee amount to prevent fee bypass attack
         let fee_amount = decimal128::mul_u64(&swap_fee_rate, amount_in);
+        if (fee_amount == 0) {
+            fee_amount = 1;
+        };
+
         let adjusted_amount_in = amount_in - fee_amount;
         let base = decimal128::from_ratio_u64(pool_amount_in, pool_amount_in + adjusted_amount_in);
         let sub_amount = pow(&base, &exp);