fix(oracle): copy ethers code while PR is to be open and merged

(cherry picked from commit da5400d)

src/common/gas.rs

@@ -225,6 +225,12 @@ impl<P: ProviderLike> FeeEstimator<P> {
     }
 }
 
+const GWEI_TO_WEI: u64 = 1_000_000_000;
+
+pub fn from_gwei_f64(gwei: f64) -> U256 {
+    U256::from((gwei * GWEI_TO_WEI as f64).ceil() as u64)
+}
+
 const NON_EIP_1559_CHAIN_IDS: &[u64] = &[
     Chain::Arbitrum as u64,
     Chain::ArbitrumNova as u64,
@@ -234,3 +240,17 @@ const NON_EIP_1559_CHAIN_IDS: &[u64] = &[
 fn is_known_non_eip_1559_chain(chain_id: u64) -> bool {
     NON_EIP_1559_CHAIN_IDS.contains(&chain_id)
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_gwei_conversion() {
+        let max_priority_fee: f64 = 1.8963421368;
+
+        let result = from_gwei_f64(max_priority_fee);
+
+        assert_eq!(result, U256::from(1896342137));
+    }
+}

src/common/mod.rs

@@ -10,6 +10,7 @@ pub mod grpc;
 pub mod handle;
 pub mod math;
 pub mod mempool;
+pub mod polygon;
 pub mod precheck;
 pub mod protos;
 pub mod retry;

src/common/polygon.rs

@@ -0,0 +1,169 @@
+// This code was taken from ethers-rs, we will remove it once our PR is merged for rounding errors
+
+use ethers::{
+    prelude::gas_oracle::{GasCategory, GasOracle, GasOracleError, Result},
+    types::{Chain, U256},
+};
+use reqwest::Client;
+use serde::Deserialize;
+use tonic::async_trait;
+use url::Url;
+
+use super::gas::from_gwei_f64;
+
+const MAINNET_URL: &str = "https://gasstation.polygon.technology/v2";
+const MUMBAI_URL: &str = "https://gasstation-testnet.polygon.technology/v2";
+
+/// The [Polygon](https://docs.polygon.technology/docs/develop/tools/polygon-gas-station/) gas station API
+/// Queries over HTTP and implements the `GasOracle` trait.
+#[derive(Clone, Debug)]
+#[must_use]
+pub struct Polygon {
+    client: Client,
+    url: Url,
+    gas_category: GasCategory,
+}
+
+/// The response from the Polygon gas station API.
+///
+/// Gas prices are in __Gwei__.
+#[derive(Debug, Deserialize, PartialEq)]
+#[serde(rename_all = "camelCase")]
+pub struct Response {
+    #[serde(deserialize_with = "deserialize_stringified_f64")]
+    pub estimated_base_fee: f64,
+    pub safe_low: GasEstimate,
+    pub standard: GasEstimate,
+    pub fast: GasEstimate,
+}
+
+#[derive(Clone, Copy, Debug, Deserialize, PartialEq)]
+#[serde(rename_all = "camelCase")]
+pub struct GasEstimate {
+    #[serde(deserialize_with = "deserialize_stringified_f64")]
+    pub max_priority_fee: f64,
+    #[serde(deserialize_with = "deserialize_stringified_f64")]
+    pub max_fee: f64,
+}
+
+fn deserialize_stringified_f64<'de, D>(deserializer: D) -> Result<f64, D::Error>
+where
+    D: serde::Deserializer<'de>,
+{
+    #[derive(Deserialize)]
+    #[serde(untagged)]
+    enum F64OrString {
+        F64(serde_json::Number),
+        String(String),
+    }
+    match Deserialize::deserialize(deserializer)? {
+        F64OrString::F64(f) => f
+            .as_f64()
+            .ok_or_else(|| serde::de::Error::custom("invalid f64")),
+        F64OrString::String(s) => s.parse().map_err(serde::de::Error::custom),
+    }
+}
+
+impl Response {
+    #[inline]
+    pub fn estimate_from_category(&self, gas_category: GasCategory) -> GasEstimate {
+        match gas_category {
+            GasCategory::SafeLow => self.safe_low,
+            GasCategory::Standard => self.standard,
+            GasCategory::Fast => self.fast,
+            GasCategory::Fastest => self.fast,
+        }
+    }
+}
+
+impl Default for Polygon {
+    fn default() -> Self {
+        Self::new(Chain::Polygon).unwrap()
+    }
+}
+
+#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
+#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
+impl GasOracle for Polygon {
+    async fn fetch(&self) -> Result<U256> {
+        let response = self.query().await?;
+        let base = response.estimated_base_fee;
+        let prio = response
+            .estimate_from_category(self.gas_category)
+            .max_priority_fee;
+        let fee = base + prio;
+        Ok(from_gwei_f64(fee))
+    }
+
+    async fn estimate_eip1559_fees(&self) -> Result<(U256, U256)> {
+        let response = self.query().await?;
+        let estimate = response.estimate_from_category(self.gas_category);
+        let max = from_gwei_f64(estimate.max_fee);
+        let prio = from_gwei_f64(estimate.max_priority_fee);
+        Ok((max, prio))
+    }
+}
+
+impl Polygon {
+    pub fn new(chain: Chain) -> Result<Self> {
+        #[cfg(not(target_arch = "wasm32"))]
+        static APP_USER_AGENT: &str =
+            concat!(env!("CARGO_PKG_NAME"), "/", env!("CARGO_PKG_VERSION"),);
+
+        let builder = Client::builder();
+        #[cfg(not(target_arch = "wasm32"))]
+        let builder = builder.user_agent(APP_USER_AGENT);
+
+        Self::with_client(builder.build()?, chain)
+    }
+
+    pub fn with_client(client: Client, chain: Chain) -> Result<Self> {
+        // TODO: Sniff chain from chain id.
+        let url = match chain {
+            Chain::Polygon => MAINNET_URL,
+            Chain::PolygonMumbai => MUMBAI_URL,
+            _ => return Err(GasOracleError::UnsupportedChain),
+        };
+        Ok(Self {
+            client,
+            url: Url::parse(url).unwrap(),
+            gas_category: GasCategory::Standard,
+        })
+    }
+
+    /// Sets the gas price category to be used when fetching the gas price.
+    pub fn category(mut self, gas_category: GasCategory) -> Self {
+        self.gas_category = gas_category;
+        self
+    }
+
+    /// Perform a request to the gas price API and deserialize the response.
+    pub async fn query(&self) -> Result<Response> {
+        let response = self
+            .client
+            .get(self.url.clone())
+            .send()
+            .await?
+            .error_for_status()?
+            .json()
+            .await?;
+        Ok(response)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parse_polygon_gas_station_response() {
+        let s = r#"{"safeLow":{"maxPriorityFee":"30.739827732","maxFee":"335.336914674"},"standard":{"maxPriorityFee":"57.257993430","maxFee":"361.855080372"},"fast":{"maxPriorityFee":"103.414268558","maxFee":"408.011355500"},"estimatedBaseFee":"304.597086942","blockTime":2,"blockNumber":43975155}"#;
+        let _resp: Response = serde_json::from_str(s).unwrap();
+    }
+
+    #[test]
+    fn parse_polygon_testnet_gas_station_response() {
+        let s = r#"{"safeLow":{"maxPriorityFee":1.3999999978,"maxFee":1.4000000157999999},"standard":{"maxPriorityFee":1.5199999980666665,"maxFee":1.5200000160666665},"fast":{"maxPriorityFee":2.0233333273333334,"maxFee":2.0233333453333335},"estimatedBaseFee":1.8e-8,"blockTime":2,"blockNumber":36917340}"#;
+        let _resp: Response = serde_json::from_str(s).unwrap();
+    }
+}