add support for polygon and avalanche (#606)

* add support for polygon and avalanche, include the block explorers

* add multicall addresses for polygon

.gitignore

@@ -1,2 +1,3 @@
 /target
-.vscode
+.vscode
+/.envrc

ethers-contract/src/multicall/mod.rs

@@ -27,6 +27,8 @@ pub static ADDRESS_BOOK: Lazy<HashMap<U256, Address>> = Lazy::new(|| {
         (Chain::Goerli.into(), decode_address("77dca2c955b15e9de4dbbcf1246b4b85b651e50e")),
         (Chain::Kovan.into(), decode_address("2cc8688c5f75e365aaeeb4ea8d6a480405a48d2a")),
         (Chain::XDai.into(), decode_address("b5b692a88bdfc81ca69dcb1d924f59f0413a602a")),
+        (Chain::Polygon.into(), decode_address("11ce4B23bD875D7F5C6a31084f55fDe1e9A87507")),
+        (Chain::PolygonMumbai.into(), decode_address("08411ADd0b5AA8ee47563b146743C13b3556c9Cc")),
     ]
     .into()
 });

ethers-core/src/types/chain.rs

@@ -10,6 +10,10 @@ pub enum Chain {
     Goerli,
     Kovan,
     XDai,
+    Polygon,
+    PolygonMumbai,
+    Avalanche,
+    AvalancheFuji,
 }
 
 impl fmt::Display for Chain {
@@ -27,6 +31,10 @@ impl From<Chain> for u32 {
             Chain::Goerli => 5,
             Chain::Kovan => 42,
             Chain::XDai => 100,
+            Chain::Polygon => 137,
+            Chain::PolygonMumbai => 80001,
+            Chain::Avalanche => 43114,
+            Chain::AvalancheFuji => 43113,
         }
     }
 }

ethers-etherscan/src/lib.rs

@@ -40,6 +40,21 @@ impl Client {
                     Url::parse(&format!("https://{}.etherscan.io", chain_name)),
                 )
             }
+            Chain::Polygon => (
+                Url::parse("https://api.polygonscan.com/api"),
+                Url::parse("https://polygonscan.com"),
+            ),
+            Chain::PolygonMumbai => (
+                Url::parse("https://api-testnet.polygonscan.com/api"),
+                Url::parse("https://mumbai.polygonscan.com"),
+            ),
+            Chain::Avalanche => {
+                (Url::parse("https://api.snowtrace.io/api"), Url::parse("https://snowtrace.io"))
+            }
+            Chain::AvalancheFuji => (
+                Url::parse("https://api-testnet.snowtrace.io/api"),
+                Url::parse("https://testnet.snowtrace.io"),
+            ),
             chain => return Err(EtherscanError::ChainNotSupported(chain)),
         };
 
@@ -54,7 +69,15 @@ impl Client {
     /// 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> {
-        Self::new(chain, std::env::var("ETHERSCAN_API_KEY")?)
+        let api_key = match chain {
+            Chain::Avalanche | Chain::AvalancheFuji => std::env::var("SNOWTRACE_API_KEY")?,
+            Chain::Polygon | Chain::PolygonMumbai => std::env::var("POLYGONSCAN_API_KEY")?,
+            Chain::Mainnet | Chain::Ropsten | Chain::Kovan | Chain::Rinkeby | Chain::Goerli => {
+                std::env::var("ETHERSCAN_API_KEY")?
+            }
+            Chain::XDai => String::default(),
+        };
+        Self::new(chain, api_key)
     }
 
     pub fn etherscan_api_url(&self) -> &Url {

scripts/examples.sh

@@ -1,5 +1,6 @@
+# shellcheck shell=bash
 # run all examples
 for file in examples/*.rs; do
-  name=`echo $file | cut -f 1 -d '.'`
+  name="$(echo "$file" | cut -f 1 -d '.')"
-  cargo r -p ethers --example `basename $name`
+  cargo r -p ethers --example "$(basename "$name")"
 done