feat(cast/send): legacy txn sending

cast/src/lib.rs

@@ -7,7 +7,7 @@ use ethers_core::{
         token::{LenientTokenizer, Tokenizer},
         Abi, AbiParser, Token,
     },
-    types::{Chain, *},
+    types::{transaction::eip2718::TypedTransaction, Chain, *},
     utils::{self, keccak256},
 };
 
@@ -216,7 +216,7 @@ where
         args: Option<(&str, Vec<String>)>,
         chain: Chain,
         etherscan_api_key: Option<String>,
-    ) -> Result<(Eip1559TransactionRequest, Option<ethers_core::abi::Function>)> {
+    ) -> Result<(TypedTransaction, Option<ethers_core::abi::Function>)> {
         let from = match from.into() {
             NameOrAddress::Name(ref ens_name) => self.provider.resolve_name(ens_name).await?,
             NameOrAddress::Address(addr) => addr,
@@ -231,7 +231,11 @@ where
         };
 
         // make the call
-        let mut tx = Eip1559TransactionRequest::new().from(from).to(to);
+        let mut tx: TypedTransaction = if is_legacy(chain) {
+            TransactionRequest::new().from(from).to(to).into()
+        } else {
+            Eip1559TransactionRequest::new().from(from).to(to).into()
+        };
 
         let func = if let Some((sig, args)) = args {
             let func = if sig.contains('(') {
@@ -247,7 +251,7 @@ where
                 .await?
             };
             let data = encode_args(&func, &args)?;
-            tx = tx.data(data);
+            tx.set_data(data.into());
             Some(func)
         } else {
             None
@@ -1042,3 +1046,16 @@ mod tests {
         );
     }
 }
+
+/// Helper function for checking if a chainid corresponds to a legacy chainid
+/// without eip1559
+fn is_legacy<T: TryInto<Chain>>(chain: T) -> bool {
+    let chain = match chain.try_into() {
+        Ok(inner) => inner,
+        _ => return false,
+    };
+
+    use Chain::*;
+    // TODO: Add other chains which do not support EIP1559.
+    matches!(chain, Optimism | OptimismKovan | Fantom | FantomTestnet)
+}

cli/src/opts/mod.rs

@@ -72,6 +72,7 @@ pub struct EthereumOpts {
 
     #[clap(long, env = "ETHERSCAN_API_KEY")]
     pub etherscan_api_key: Option<String>,
+
     #[clap(long, env = "CHAIN", default_value = "mainnet")]
     pub chain: Chain,
 }