fix: basefee opcode pushes base_fee value (#956)

* fix: basefee opcode pushes base_fee value

* remove custom name for contract target

crates/evm/src/instructions/block_information.cairo

@@ -111,9 +111,7 @@ pub impl BlockInformation of BlockInformationTrait {
     fn exec_basefee(ref self: VM) -> Result<(), EVMError> {
         self.charge_gas(gas::BASE)?;
 
-        // Get the current base fee. (Kakarot doesn't use EIP 1559 so basefee
-        //  doesn't really exists there so we just use the gas price)
-        self.stack.push(self.env.gas_price.into())
+        self.stack.push(self.env.base_fee.into())
     }
 
     /// 0x49 - BLOBHASH
@@ -284,16 +282,16 @@ mod tests {
 
 
     #[test]
-    fn test_basefee() {
+    fn test_basefee_should_push_env_base_fee() {
         // Given
         let mut vm = VMBuilderTrait::new_with_presets().build();
 
         // When
         vm.exec_basefee().unwrap();
 
         // Then
-        assert(vm.stack.len() == 1, 'stack should have one element');
-        assert(vm.stack.peek().unwrap() == gas_price().into(), 'stack top should be gas_price');
+        assert_eq!(vm.stack.len(), 1);
+        assert_eq!(vm.stack.peek().unwrap(), vm.env.base_fee.into());
     }
 
     #[test]

crates/evm/src/test_utils.cairo

@@ -200,10 +200,10 @@ pub fn tx_gas_limit() -> u64 {
     constants::BLOCK_GAS_LIMIT
 }
 
-pub const BASE_FEE: u128 = 1000;
+pub const BASE_FEE: u64 = 1000;
 
 pub fn gas_price() -> u128 {
-    BASE_FEE + 1
+    BASE_FEE.into() + 1
 }
 
 pub fn value() -> u256 {
@@ -262,7 +262,7 @@ pub fn preset_environment() -> Environment {
         block_timestamp: block_info.block_timestamp,
         block_gas_limit: constants::BLOCK_GAS_LIMIT,
         coinbase: coinbase(),
-        base_fee: 0,
+        base_fee: BASE_FEE,
         state: Default::default(),
     }
 }