refactor(core, contract, etherscan): move Chain enum, use HashMap::from (#524)

* refactor(contract, etherscan): make use of HashMap::from

* feat(core): Chain enum

* rename unknown chain error

* reorg imports

ethers-contract/src/multicall/mod.rs

@@ -1,6 +1,6 @@
 use ethers_core::{
     abi::{Detokenize, Function, Token},
-    types::{Address, BlockNumber, Bytes, NameOrAddress, TxHash, U256},
+    types::{Address, BlockNumber, Bytes, Chain, NameOrAddress, TxHash, U256},
 };
 use ethers_providers::Middleware;
 
@@ -17,34 +17,33 @@ use multicall_contract::MulticallContract;
 /// A lazily computed hash map with the Ethereum network IDs as keys and the corresponding
 /// Multicall smart contract addresses as values
 pub static ADDRESS_BOOK: Lazy<HashMap<U256, Address>> = Lazy::new(|| {
-    let mut m = HashMap::new();
+    fn decode_address(input: &str) -> Address {
+        Address::from_str(input).expect("Decoding failed")
+    }
 
-    // mainnet
-    let addr =
-        Address::from_str("eefba1e63905ef1d7acba5a8513c70307c1ce441").expect("Decoding failed");
-    m.insert(U256::from(1u8), addr);
-
-    // rinkeby
-    let addr =
-        Address::from_str("42ad527de7d4e9d9d011ac45b31d8551f8fe9821").expect("Decoding failed");
-    m.insert(U256::from(4u8), addr);
-
-    // goerli
-    let addr =
-        Address::from_str("77dca2c955b15e9de4dbbcf1246b4b85b651e50e").expect("Decoding failed");
-    m.insert(U256::from(5u8), addr);
-
-    // kovan
-    let addr =
-        Address::from_str("2cc8688c5f75e365aaeeb4ea8d6a480405a48d2a").expect("Decoding failed");
-    m.insert(U256::from(42u8), addr);
-
-    // xdai
-    let addr =
-        Address::from_str("b5b692a88bdfc81ca69dcb1d924f59f0413a602a").expect("Decoding failed");
-    m.insert(U256::from(100u8), addr);
-
-    m
+    [
+        (
+            Chain::Mainnet.into(),
+            decode_address("eefba1e63905ef1d7acba5a8513c70307c1ce441"),
+        ),
+        (
+            Chain::Rinkeby.into(),
+            decode_address("42ad527de7d4e9d9d011ac45b31d8551f8fe9821"),
+        ),
+        (
+            Chain::Goerli.into(),
+            decode_address("77dca2c955b15e9de4dbbcf1246b4b85b651e50e"),
+        ),
+        (
+            Chain::Kovan.into(),
+            decode_address("2cc8688c5f75e365aaeeb4ea8d6a480405a48d2a"),
+        ),
+        (
+            Chain::XDai.into(),
+            decode_address("b5b692a88bdfc81ca69dcb1d924f59f0413a602a"),
+        ),
+    ]
+    .into()
 });
 
 /// A Multicall is an abstraction for sending batched calls/transactions to the Ethereum blockchain.

ethers-core/src/types/chain.rs

@@ -0,0 +1,38 @@
+use std::fmt;
+
+use crate::types::U256;
+
+#[derive(Debug)]
+pub enum Chain {
+    Mainnet,
+    Ropsten,
+    Rinkeby,
+    Goerli,
+    Kovan,
+    XDai,
+}
+
+impl fmt::Display for Chain {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "{:?}", self)
+    }
+}
+
+impl From<Chain> for u32 {
+    fn from(chain: Chain) -> Self {
+        match chain {
+            Chain::Mainnet => 1,
+            Chain::Ropsten => 3,
+            Chain::Rinkeby => 4,
+            Chain::Goerli => 5,
+            Chain::Kovan => 42,
+            Chain::XDai => 100,
+        }
+    }
+}
+
+impl From<Chain> for U256 {
+    fn from(chain: Chain) -> Self {
+        u32::from(chain).into()
+    }
+}

ethers-core/src/types/mod.rs

@@ -48,5 +48,9 @@ pub use txpool::*;
 mod trace;
 pub use trace::*;
 
+mod chain;
+pub use chain::*;
+
 mod proof;
+
 pub use proof::*;

ethers-etherscan/src/contract.rs

@@ -206,40 +206,42 @@ impl Client {
         &self,
         guid: impl AsRef<str>,
     ) -> Result<Response<String>> {
-        let mut map = HashMap::new();
-        map.insert("guid", guid.as_ref());
-        let body = self.create_query("contract", "checkverifystatus", map);
+        let body = self.create_query(
+            "contract",
+            "checkverifystatus",
+            HashMap::from([("guid", guid.as_ref())]),
+        );
         Ok(self.post_form(&body).await?)
     }
 
     /// Returns the contract ABI of a verified contract
     ///
     /// ```no_run
-    /// # use ethers_etherscan::{Chain, Client};
+    /// # use ethers_etherscan::Client;
+    /// # use ethers_core::types::Chain;
     ///
     /// # #[tokio::main]
     /// # async fn main() {
-    ///     let client = Client::new(Chain::Mainnet, "API_KEY");
+    ///     let client = Client::new(Chain::Mainnet, "API_KEY").unwrap();
     ///     let abi = client
     ///         .contract_abi("0xBB9bc244D798123fDe783fCc1C72d3Bb8C189413".parse().unwrap())
     ///         .await.unwrap();
     /// # }
     /// ```
     pub async fn contract_abi(&self, address: Address) -> Result<Abi> {
-        let mut map = HashMap::new();
-        map.insert("address", address);
-        let query = self.create_query("contract", "getabi", map);
+        let query = self.create_query("contract", "getabi", HashMap::from([("address", address)]));
         let resp: Response<String> = self.get_json(&query).await?;
         Ok(serde_json::from_str(&resp.result)?)
     }
 
     /// Get Contract Source Code for Verified Contract Source Codes
     /// ```no_run
-    /// # use ethers_etherscan::{Chain, Client};
+    /// # use ethers_etherscan::Client;
+    /// # use ethers_core::types::Chain;
     ///
     /// # #[tokio::main]
     /// # async fn main() {
-    ///     let client = Client::new(Chain::Mainnet, "API_KEY");
+    ///     let client = Client::new(Chain::Mainnet, "API_KEY").unwrap();
     ///     let meta = client
     ///         .contract_source_code("0xBB9bc244D798123fDe783fCc1C72d3Bb8C189413".parse().unwrap())
     ///         .await.unwrap();
@@ -247,9 +249,11 @@ impl Client {
     /// # }
     /// ```
     pub async fn contract_source_code(&self, address: Address) -> Result<ContractMetadata> {
-        let mut map = HashMap::new();
-        map.insert("address", address);
-        let query = self.create_query("contract", "getsourcecode", map);
+        let query = self.create_query(
+            "contract",
+            "getsourcecode",
+            HashMap::from([("address", address)]),
+        );
         let response: Response<Vec<Metadata>> = self.get_json(&query).await?;
         Ok(ContractMetadata {
             items: response.result,
@@ -259,8 +263,8 @@ impl Client {
 
 #[cfg(test)]
 mod tests {
-    use crate::contract::VerifyContract;
-    use crate::{Chain, Client};
+    use crate::{contract::VerifyContract, Client};
+    use ethers_core::types::Chain;
 
     #[tokio::test]
     #[ignore]

ethers-etherscan/src/errors.rs

@@ -1,7 +1,10 @@
+use ethers_core::types::Chain;
 use std::env::VarError;
 
 #[derive(Debug, thiserror::Error)]
 pub enum EtherscanError {
+    #[error("chain {0} not supported")]
+    ChainNotSupported(Chain),
     #[error("contract execution call failed: {0}")]
     ExecutionFailed(String),
     #[error("tx receipt failed")]

ethers-etherscan/src/lib.rs

@@ -5,15 +5,15 @@ mod errors;
 mod transaction;
 
 use errors::EtherscanError;
-use ethers_core::abi::Address;
+use ethers_core::{abi::Address, types::Chain};
 use reqwest::{header, Url};
 use serde::{de::DeserializeOwned, Deserialize, Serialize};
-use std::{borrow::Cow, fmt};
+use std::borrow::Cow;
 
 pub type Result<T> = std::result::Result<T, EtherscanError>;
 
 /// The Etherscan.io API client.
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct Client {
     /// Client that executes HTTP requests
     client: reqwest::Client,
@@ -25,47 +25,37 @@ pub struct Client {
     etherscan_url: Url,
 }
 
-#[derive(Debug)]
-pub enum Chain {
-    Mainnet,
-    Ropsten,
-    Kovan,
-    Rinkeby,
-    Goerli,
-}
-
-impl fmt::Display for Chain {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        write!(formatter, "{}", format!("{:?}", self).to_lowercase())
-    }
-}
-
 impl Client {
     /// Create a new client with the correct endpoints based on the chain and provided API key
-    pub fn new(chain: Chain, api_key: impl Into<String>) -> Self {
+    pub fn new(chain: Chain, api_key: impl Into<String>) -> Result<Self> {
         let (etherscan_api_url, etherscan_url) = match chain {
             Chain::Mainnet => (
                 Url::parse("https://api.etherscan.io/api"),
                 Url::parse("https://etherscan.io"),
             ),
-            Chain::Ropsten | Chain::Kovan | Chain::Rinkeby | Chain::Goerli => (
-                Url::parse(&format!("https://api-{}.etherscan.io/api", chain)),
-                Url::parse(&format!("https://{}.etherscan.io", chain)),
-            ),
+            Chain::Ropsten | Chain::Kovan | Chain::Rinkeby | Chain::Goerli => {
+                let chain_name = chain.to_string().to_lowercase();
+
+                (
+                    Url::parse(&format!("https://api-{}.etherscan.io/api", chain_name)),
+                    Url::parse(&format!("https://{}.etherscan.io", chain_name)),
+                )
+            }
+            chain => return Err(EtherscanError::ChainNotSupported(chain)),
         };
 
-        Self {
+        Ok(Self {
             client: Default::default(),
             api_key: api_key.into(),
             etherscan_api_url: etherscan_api_url.expect("is valid http"),
             etherscan_url: etherscan_url.expect("is valid http"),
-        }
+        })
     }
 
     /// Create a new client with the correct endpoints based on the chain and API key
     /// from ETHERSCAN_API_KEY environment variable
     pub fn new_from_env(chain: Chain) -> Result<Self> {
-        Ok(Self::new(chain, std::env::var("ETHERSCAN_API_KEY")?))
+        Self::new(chain, std::env::var("ETHERSCAN_API_KEY")?)
     }
 
     pub fn etherscan_api_url(&self) -> &Url {
@@ -157,3 +147,17 @@ struct Query<'a, T: Serialize> {
     #[serde(flatten)]
     other: T,
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::{Client, EtherscanError};
+    use ethers_core::types::Chain;
+
+    #[test]
+    fn chain_not_supported() {
+        let err = Client::new_from_env(Chain::XDai).unwrap_err();
+
+        assert!(matches!(err, EtherscanError::ChainNotSupported(_)));
+        assert_eq!(err.to_string(), "chain XDai not supported");
+    }
+}

ethers-etherscan/src/transaction.rs

@@ -22,7 +22,11 @@ impl Client {
         let mut map = HashMap::new();
         map.insert("txhash", tx_hash.as_ref());
 
-        let query = self.create_query("transaction", "getstatus", map);
+        let query = self.create_query(
+            "transaction",
+            "getstatus",
+            HashMap::from([("txhash", tx_hash.as_ref())]),
+        );
         let response: Response<ContractExecutionStatus> = self.get_json(&query).await?;
 
         if response.result.is_error == "0" {
@@ -36,10 +40,11 @@ impl Client {
 
     /// Returns the status of a transaction execution: `false` for failed and `true` for successful
     pub async fn check_transaction_receipt_status(&self, tx_hash: impl AsRef<str>) -> Result<()> {
-        let mut map = HashMap::new();
-        map.insert("txhash", tx_hash.as_ref());
-
-        let query = self.create_query("transaction", "gettxreceiptstatus", map);
+        let query = self.create_query(
+            "transaction",
+            "gettxreceiptstatus",
+            HashMap::from([("txhash", tx_hash.as_ref())]),
+        );
         let response: Response<TransactionReceiptStatus> = self.get_json(&query).await?;
 
         match response.result.status.as_str() {