feat: add support for custom fee tier (#107)

Introduced a `CUSTOM` variant to `FeeAmount` enum to allow arbitrary fee values. Updated related functionality to handle custom fees and made necessary changes to dependent modules. Bumped version to 2.7.0 in Cargo.toml and README.md.

Cargo.toml

@@ -1,12 +1,13 @@
 [package]
 name = "uniswap-v3-sdk"
-version = "2.6.0"
+version = "2.7.0"
 edition = "2021"
 authors = ["Shuhui Luo <twitter.com/aureliano_law>"]
 description = "Uniswap V3 SDK for Rust"
 license = "MIT"
 readme = "README.md"
 repository = "https://github.com/shuhuiluo/uniswap-v3-sdk-rs"
+categories = ["cryptography::cryptocurrencies", "finance", "no-std"]
 keywords = ["uniswap-v3", "ethereum", "sdk"]
 exclude = [".github", ".gitignore", "rustfmt.toml"]
 

README.md

@@ -49,7 +49,7 @@ It is feature-complete with unit tests matching the TypeScript SDK.
 Add the following to your `Cargo.toml` file:
 
 ```toml
-uniswap-v3-sdk = { version = "2.5.0", features = ["extensions", "std"] }
+uniswap-v3-sdk = { version = "2.7.0", features = ["extensions", "std"] }
 ```
 
 ### Usage

src/constants.rs

@@ -21,13 +21,14 @@ pub enum FeeAmount {
     LOW = 500,
     MEDIUM = 3000,
     HIGH = 10000,
+    CUSTOM(u32),
 }
 
 impl FeeAmount {
     /// The default factory tick spacings by fee amount.
     #[inline]
     #[must_use]
-    pub const fn tick_spacing(&self) -> I24 {
+    pub fn tick_spacing(&self) -> I24 {
         match self {
             Self::LOWEST => I24::ONE,
             Self::LOW_200 => I24::from_limbs([4]),
@@ -36,6 +37,7 @@ impl FeeAmount {
             Self::LOW => I24::from_limbs([10]),
             Self::MEDIUM => I24::from_limbs([60]),
             Self::HIGH => I24::from_limbs([200]),
+            Self::CUSTOM(fee) => I24::from_limbs([(fee / 50) as u64]),
         }
     }
 }
@@ -51,7 +53,7 @@ impl From<u32> for FeeAmount {
             500 => Self::LOW,
             3000 => Self::MEDIUM,
             10000 => Self::HIGH,
-            _ => panic!("Invalid fee amount"),
+            fee => Self::CUSTOM(fee),
         }
     }
 }
@@ -67,15 +69,24 @@ impl From<i32> for FeeAmount {
             10 => Self::LOW,
             60 => Self::MEDIUM,
             200 => Self::HIGH,
-            _ => panic!("Invalid tick spacing"),
+            tick_spacing => Self::CUSTOM((tick_spacing * 50) as u32),
         }
     }
 }
 
 impl From<FeeAmount> for U24 {
     #[inline]
     fn from(fee: FeeAmount) -> Self {
-        Self::from_limbs([fee as u64])
+        Self::from_limbs([match fee {
+            FeeAmount::LOWEST => 100,
+            FeeAmount::LOW_200 => 200,
+            FeeAmount::LOW_300 => 300,
+            FeeAmount::LOW_400 => 400,
+            FeeAmount::LOW => 500,
+            FeeAmount::MEDIUM => 3000,
+            FeeAmount::HIGH => 10000,
+            FeeAmount::CUSTOM(fee) => fee as u64,
+        }])
     }
 }
 

src/entities/position.rs

@@ -508,7 +508,7 @@ mod tests {
         Lazy::new(|| encode_sqrt_ratio_x96(BigInt::from(10).pow(8), BigInt::from(10).pow(20)));
     static POOL_TICK_CURRENT: Lazy<I24> =
         Lazy::new(|| POOL_SQRT_RATIO_START.get_tick_at_sqrt_ratio().unwrap());
-    const TICK_SPACING: I24 = FeeAmount::LOW.tick_spacing();
+    const TICK_SPACING: I24 = I24::from_limbs([10]);
 
     static DAI_USDC_POOL: Lazy<Pool> = Lazy::new(|| {
         Pool::new(

src/utils/compute_pool_address.rs

@@ -1,5 +1,5 @@
 use crate::constants::{FeeAmount, POOL_INIT_CODE_HASH};
-use alloy_primitives::{b256, keccak256, Address, B256};
+use alloy_primitives::{aliases::U24, b256, keccak256, Address, B256};
 use alloy_sol_types::SolValue;
 use uniswap_sdk_core::prelude::{
     compute_zksync_create2_address::compute_zksync_create2_address, ChainId,
@@ -66,7 +66,8 @@ pub fn compute_pool_address(
     } else {
         (token_b, token_a)
     };
-    let salt = keccak256((token_0, token_1, fee as i32).abi_encode());
+    let fee: U24 = fee.into();
+    let salt = keccak256((token_0, token_1, fee).abi_encode());
     const ZKSYNC_CHAIN_ID: u64 = ChainId::ZKSYNC as u64;
 
     // ZKSync uses a different create2 address computation