feat: improve test full block fee is correct #465 (#466)

feat: improved test full_block_fee_is_correct to calculate the expected max block fee

substrate-node/runtime/src/constants.rs

@@ -97,9 +97,17 @@ mod tests {
     fn full_block_fee_is_correct() {
         // A full block should cost 23.3112 DOLLARS
         log::info!("MaxBlockWeight: {:?}", MaximumBlockWeight::get());
+        log::info!("BaseWeight: {:?}", ExtrinsicBaseWeight::get());
+        // we multiply by 100 to avoid loss of precision after division and devide by 100 at the end
+        let precision = 100;
+        let max_block_weight: u128 = (MaximumBlockWeight::get() as u128) * precision;
+        let ext_base_weight: u128 = ExtrinsicBaseWeight::get() as u128;
         let x = WeightToFeeStruct::weight_to_fee(&MaximumBlockWeight::get());
-        let y = 2331120 * MILLICENTS;
-        assert!(x.max(y) - x.min(y) < MILLICENTS);
+        let cost_extrinsic:u128 = WeightToFeeStruct::weight_to_fee(&ExtrinsicBaseWeight::get());
+        let y:u128 = (cost_extrinsic * (max_block_weight/ext_base_weight)) / precision;
+        // Difference should be less then the cost of an extrinsic devided by 2 as we can execute Z amount of extrinsics and Z was calculated by deviding
+        // the max amount of weight per block by the weight of one extrinsic. That operation results in a loss of precision (from float to integer).
+        assert!(x.max(y) - x.min(y) < cost_extrinsic / 2);
     }
 
     #[test]