feat: support block option in cast call (gakonst#638)

cast/src/lib.rs

@@ -73,11 +73,12 @@ where
         args: (&str, Vec<String>),
         chain: Chain,
         etherscan_api_key: Option<String>,
+        block: Option<BlockId>,
     ) -> Result<String> {
         let (tx, func) = self
             .build_tx(from, to, Some(args), None, None, None, chain, etherscan_api_key, false)
             .await?;
-        let res = self.provider.call(&tx, None).await?;
+        let res = self.provider.call(&tx, block).await?;
 
         // decode args into tokens
         let func = func.expect("no valid function signature was provided.");

cli/src/cast.rs

@@ -139,7 +139,7 @@ async fn main() -> eyre::Result<()> {
             let provider = Provider::try_from(rpc_url)?;
             println!("{}", Cast::new(provider).block_number().await?);
         }
-        Subcommands::Call { eth, address, sig, args } => {
+        Subcommands::Call { eth, address, sig, args, block } => {
             let provider = Provider::try_from(eth.rpc_url()?)?;
             println!(
                 "{}",
@@ -149,7 +149,8 @@ async fn main() -> eyre::Result<()> {
                         address,
                         (&sig, args),
                         eth.chain,
-                        eth.etherscan_api_key
+                        eth.etherscan_api_key,
+                        block
                     )
                     .await?
             );

cli/src/opts/cast.rs

@@ -111,6 +111,8 @@ pub enum Subcommands {
         address: NameOrAddress,
         sig: String,
         args: Vec<String>,
+        #[clap(long, short, help = "the block you want to query, can also be earliest/latest/pending", parse(try_from_str = parse_block_id))]
+        block: Option<BlockId>,
         #[clap(flatten)]
         eth: EthereumOpts,
     },