fix: gwei wei wrong u256 constant (#1992)

ethers-middleware/src/gas_oracle/mod.rs

@@ -37,7 +37,7 @@ use std::{error::Error, fmt::Debug};
 use thiserror::Error;
 
 pub(crate) const GWEI_TO_WEI: u64 = 1_000_000_000;
-pub(crate) const GWEI_TO_WEI_U256: U256 = U256([0, 0, 0, GWEI_TO_WEI]);
+pub(crate) const GWEI_TO_WEI_U256: U256 = U256([GWEI_TO_WEI, 0, 0, 0]);
 
 pub type Result<T, E = GasOracleError> = std::result::Result<T, E>;
 
@@ -153,3 +153,15 @@ pub trait GasOracle: Send + Sync + Debug {
 pub(crate) fn from_gwei_f64(gwei: f64) -> U256 {
     ethers_core::types::u256_from_f64_saturating(gwei) * GWEI_TO_WEI_U256
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_gwei_wei_constants() {
+        let as_u256: U256 = GWEI_TO_WEI.into();
+        assert_eq!(as_u256, GWEI_TO_WEI_U256);
+        assert_eq!(GWEI_TO_WEI_U256.as_u64(), GWEI_TO_WEI);
+    }
+}

ethers-middleware/src/gas_oracle/polygon.rs

@@ -20,7 +20,7 @@ pub struct Polygon {
 
 /// The response from the Polygon gas station API.
 ///
-/// Gas prices are in Gwei.
+/// Gas prices are in __Gwei__.
 #[derive(Debug, Deserialize, PartialEq)]
 #[serde(rename_all = "camelCase")]
 pub struct Response {
@@ -103,3 +103,14 @@ impl Polygon {
         Ok(response)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[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 _resp: Response = serde_json::from_str(s).unwrap();
+    }
+}