chore: remove GasNow api since it's deprecated (#508)

:rip:

CHANGELOG.md

@@ -50,6 +50,8 @@
 
 ### Unreleased
 
+- Removes GasNow as a gas price oracle [#508](https://github.com/gakonst/ethers-rs/pull/508)
+
 ### 0.5.3
 
 - Added Time Lagged middleware [#457](https://github.com/gakonst/ethers-rs/pull/457)

ethers-middleware/src/gas_escalator/mod.rs

@@ -47,7 +47,7 @@ pub enum Frequency {
 /// use ethers_providers::{Provider, Http};
 /// use ethers_middleware::{
 ///     gas_escalator::{GeometricGasPrice, Frequency, GasEscalatorMiddleware},
-///     gas_oracle::{GasNow, GasCategory, GasOracleMiddleware},
+///     gas_oracle::{EthGasStation, GasCategory, GasOracleMiddleware},
 /// };
 /// use std::{convert::TryFrom, time::Duration, sync::Arc};
 ///
@@ -61,7 +61,7 @@ pub enum Frequency {
 /// };
 ///
 /// // ... proceed to wrap it in other middleware
-/// let gas_oracle = GasNow::new().category(GasCategory::SafeLow);
+/// let gas_oracle = EthGasStation::new(None).category(GasCategory::SafeLow);
 /// let provider = GasOracleMiddleware::new(provider, gas_oracle);
 /// ```
 pub struct GasEscalatorMiddleware<M, E> {

ethers-middleware/src/gas_oracle/gas_now.rs

@@ -1,88 +0,0 @@
-use ethers_core::types::U256;
-
-use async_trait::async_trait;
-use reqwest::Client;
-use serde::Deserialize;
-use url::Url;
-
-use crate::gas_oracle::{GasCategory, GasOracle, GasOracleError};
-
-const GAS_NOW_URL: &str = "https://www.gasnow.org/api/v3/gas/price";
-
-/// A client over HTTP for the [GasNow](https://www.gasnow.org/api/v1/gas/price) gas tracker API
-/// that implements the `GasOracle` trait
-#[derive(Clone, Debug)]
-pub struct GasNow {
-    client: Client,
-    url: Url,
-    gas_category: GasCategory,
-}
-
-impl Default for GasNow {
-    fn default() -> Self {
-        Self::new()
-    }
-}
-
-#[derive(Deserialize)]
-struct GasNowResponseWrapper {
-    data: GasNowResponse,
-}
-
-#[derive(Clone, Debug, Deserialize, PartialEq, PartialOrd)]
-pub struct GasNowResponse {
-    pub rapid: u64,
-    pub fast: u64,
-    pub standard: u64,
-    pub slow: u64,
-}
-
-impl GasNow {
-    /// Creates a new [GasNow](https://gasnow.org) gas price oracle.
-    pub fn new() -> Self {
-        let url = Url::parse(GAS_NOW_URL).expect("invalid url");
-
-        Self {
-            client: Client::new(),
-            url,
-            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
-    }
-
-    pub async fn query(&self) -> Result<GasNowResponse, GasOracleError> {
-        let res = self
-            .client
-            .get(self.url.as_ref())
-            .send()
-            .await?
-            .json::<GasNowResponseWrapper>()
-            .await?;
-        Ok(res.data)
-    }
-}
-
-#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
-#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
-impl GasOracle for GasNow {
-    async fn fetch(&self) -> Result<U256, GasOracleError> {
-        let res = self.query().await?;
-        let gas_price = match self.gas_category {
-            GasCategory::SafeLow => U256::from(res.slow),
-            GasCategory::Standard => U256::from(res.standard),
-            GasCategory::Fast => U256::from(res.fast),
-            GasCategory::Fastest => U256::from(res.rapid),
-        };
-
-        Ok(gas_price)
-    }
-
-    async fn estimate_eip1559_fees(&self) -> Result<(U256, U256), GasOracleError> {
-        Err(GasOracleError::Eip1559EstimationNotSupported)
-    }
-}

ethers-middleware/src/gas_oracle/mod.rs

@@ -7,9 +7,6 @@ pub use etherchain::Etherchain;
 mod etherscan;
 pub use etherscan::Etherscan;
 
-mod gas_now;
-pub use gas_now::GasNow;
-
 mod middleware;
 pub use middleware::{GasOracleMiddleware, MiddlewareError};
 

ethers-middleware/src/lib.rs

@@ -23,7 +23,7 @@
 //! use ethers_signers::{LocalWallet, Signer};
 //! use ethers_middleware::{
 //!     gas_escalator::{GasEscalatorMiddleware, GeometricGasPrice, Frequency},
-//!     gas_oracle::{GasOracleMiddleware, GasNow, GasCategory},
+//!     gas_oracle::{GasOracleMiddleware, EthGasStation, GasCategory},
 //!     signer::SignerMiddleware,
 //!     nonce_manager::NonceManagerMiddleware,
 //! };
@@ -43,8 +43,8 @@
 //! let address = signer.address();
 //! let provider = SignerMiddleware::new(provider, signer);
 //!
-//! // Use GasNow as the gas oracle
-//! let gas_oracle = GasNow::new().category(GasCategory::SafeLow);
+//! // Use EthGasStation as the gas oracle
+//! let gas_oracle = EthGasStation::new(None);
 //! let provider = GasOracleMiddleware::new(provider, gas_oracle);
 //!
 //! // Manage nonces locally

ethers-middleware/tests/gas_oracle.rs

@@ -1,7 +1,7 @@
 #![cfg(not(target_arch = "wasm32"))]
 use ethers_core::{types::*, utils::Ganache};
 use ethers_middleware::gas_oracle::{
-    EthGasStation, Etherchain, Etherscan, GasCategory, GasNow, GasOracle, GasOracleMiddleware,
+    EthGasStation, Etherchain, Etherscan, GasCategory, GasOracle, GasOracleMiddleware,
 };
 use ethers_providers::{Http, Middleware, Provider};
 use std::convert::TryFrom;
@@ -16,7 +16,7 @@ async fn using_gas_oracle() {
     let provider = Provider::<Http>::try_from(ganache.endpoint()).unwrap();
 
     // assign a gas oracle to use
-    let gas_oracle = GasNow::new().category(GasCategory::Fastest);
+    let gas_oracle = EthGasStation::new(None);
     let expected_gas_price = gas_oracle.fetch().await.unwrap();
 
     let provider = GasOracleMiddleware::new(provider, gas_oracle);
@@ -65,11 +65,3 @@ async fn etherchain() {
     let data = etherchain_oracle.fetch().await;
     assert!(data.is_ok());
 }
-
-#[tokio::test]
-async fn gas_now() {
-    // initialize and fetch gas estimates from SparkPool
-    let gas_now_oracle = GasNow::new().category(GasCategory::Fastest);
-    let data = gas_now_oracle.fetch().await;
-    assert!(data.is_ok());
-}

ethers-middleware/tests/stack.rs

@@ -4,7 +4,7 @@ mod tests {
     use ethers_core::{rand::thread_rng, types::TransactionRequest, utils::Ganache};
     use ethers_middleware::{
         gas_escalator::{Frequency, GasEscalatorMiddleware, GeometricGasPrice},
-        gas_oracle::{GasCategory, GasNow, GasOracleMiddleware},
+        gas_oracle::{EthGasStation, GasCategory, GasOracleMiddleware},
         nonce_manager::NonceManagerMiddleware,
         signer::SignerMiddleware,
     };
@@ -17,7 +17,7 @@ mod tests {
         let (provider, mock) = Provider::mocked();
 
         // add a bunch of middlewares
-        let gas_oracle = GasNow::new().category(GasCategory::SafeLow);
+        let gas_oracle = EthGasStation::new(None).category(GasCategory::SafeLow);
         let signer = LocalWallet::new(&mut thread_rng());
         let address = signer.address();
         let escalator = GeometricGasPrice::new(1.125, 60u64, None::<u64>);
@@ -53,7 +53,7 @@ mod tests {
     #[tokio::test]
     async fn can_stack_middlewares() {
         let ganache = Ganache::new().block_time(5u64).spawn();
-        let gas_oracle = GasNow::new().category(GasCategory::SafeLow);
+        let gas_oracle = EthGasStation::new(None).category(GasCategory::SafeLow);
         let signer: LocalWallet = ganache.keys()[0].clone().into();
         let address = signer.address();