fix(middleware): polygon gas stations (#2479)

* fix(middleware): polygon gas stations

* fix: wasm

ethers-middleware/src/gas_escalator/mod.rs

@@ -36,8 +36,8 @@ pub trait GasEscalator: Send + Sync + std::fmt::Debug {
     fn get_gas_price(&self, initial_price: U256, time_elapsed: u64) -> U256;
 }
 
-#[derive(Error, Debug)]
 /// Error thrown when the GasEscalator interacts with the blockchain
+#[derive(Debug, Error)]
 pub enum GasEscalatorError<M: Middleware> {
     #[error("{0}")]
     /// Thrown when an internal middleware errors
@@ -63,8 +63,8 @@ impl<M: Middleware> MiddlewareError for GasEscalatorError<M> {
     }
 }
 
-#[derive(Debug, Clone, Copy)]
 /// The frequency at which transactions will be bumped
+#[derive(Debug, Clone, Copy)]
 pub enum Frequency {
     /// On a per block basis using the eth_newBlock filter
     PerBlock,
@@ -81,7 +81,6 @@ pub(crate) struct GasEscalatorMiddlewareInternal<M> {
     _background: oneshot::Sender<()>,
 }
 
-#[derive(Debug, Clone)]
 /// A Gas escalator allows bumping transactions' gas price to avoid getting them
 /// stuck in the memory pool.
 ///
@@ -137,6 +136,7 @@ pub(crate) struct GasEscalatorMiddlewareInternal<M> {
 /// let gas_oracle = GasNow::new().category(GasCategory::SafeLow);
 /// let provider = GasOracleMiddleware::new(provider, gas_oracle);
 /// ```
+#[derive(Debug, Clone)]
 pub struct GasEscalatorMiddleware<M> {
     pub(crate) inner: Arc<GasEscalatorMiddlewareInternal<M>>,
 }
@@ -229,6 +229,7 @@ where
     }
 }
 
+#[cfg(not(target_arch = "wasm32"))]
 #[derive(Debug)]
 pub struct EscalationTask<M, E> {
     inner: M,
@@ -238,6 +239,7 @@ pub struct EscalationTask<M, E> {
     shutdown: oneshot::Receiver<()>,
 }
 
+#[cfg(not(target_arch = "wasm32"))]
 impl<M, E> EscalationTask<M, E> {
     pub fn new(
         inner: M,

ethers-middleware/src/gas_oracle/polygon.rs

@@ -5,8 +5,8 @@ use reqwest::Client;
 use serde::Deserialize;
 use url::Url;
 
-const MAINNET_URL: &str = "https://gasstation-mainnet.matic.network/v2";
-const MUMBAI_URL: &str = "https://gasstation-mumbai.matic.today/v2";
+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.
@@ -24,6 +24,7 @@ pub struct Polygon {
 #[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,
@@ -33,10 +34,28 @@ pub struct Response {
 #[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 {
@@ -77,7 +96,15 @@ impl GasOracle for Polygon {
 
 impl Polygon {
     pub fn new(chain: Chain) -> Result<Self> {
-        Self::with_client(Client::new(), chain)
+        #[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> {
@@ -110,7 +137,13 @@ mod tests {
 
     #[test]
     fn parse_polygon_gas_station_response() {
-        let s = r#"{"safeLow":{"maxPriorityFee":2.1267086610666666,"maxFee":2.1267086760666665},"standard":{"maxPriorityFee":2.3482958369333335,"maxFee":2.3482958519333335},"fast":{"maxPriorityFee":2.793454819,"maxFee":2.793454834},"estimatedBaseFee":1.5e-8,"blockTime":2,"blockNumber":30328888}"#;
+        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();
     }
 }