add cast abi-encode (#374)

cast/src/lib.rs

@@ -592,6 +592,27 @@ impl SimpleCast {
         foundry_utils::abi_decode(sig, calldata, input)
     }
 
+    /// Performs ABI encoding based off of the function signature. Does not include
+    /// the function selector in the result.
+    ///
+    /// ```
+    /// # use cast::SimpleCast as Cast;
+    ///
+    /// # fn main() -> eyre::Result<()> {
+    ///     assert_eq!(
+    ///         "0x0000000000000000000000000000000000000000000000000000000000000001",
+    ///         Cast::abi_encode("f(uint a)", &["1"]).unwrap().as_str()
+    ///     );
+    /// #    Ok(())
+    /// # }
+    /// ```
+    pub fn abi_encode(sig: &str, args: &[impl AsRef<str>]) -> Result<String> {
+        let func = AbiParser::default().parse_function(sig.as_ref())?;
+        let calldata = encode_args(&func, args)?.to_hex::<String>();
+        let encoded = &calldata[8..];
+        Ok(format!("0x{}", encoded))
+    }
+
     /// Converts decimal input to hex
     ///
     /// ```

cli/src/cast.rs

@@ -204,6 +204,9 @@ async fn main() -> eyre::Result<()> {
             let tokens = foundry_utils::format_tokens(&tokens);
             tokens.for_each(|t| println!("{}", t));
         }
+        Subcommands::AbiEncode { sig, args } => {
+            println!("{}", SimpleCast::abi_encode(&sig, &args)?);
+        }
         Subcommands::FourByte { selector } => {
             let sigs = foundry_utils::fourbyte(&selector).await?;
             sigs.iter().for_each(|sig| println!("{}", sig.0));

cli/src/opts/cast.rs

@@ -178,6 +178,16 @@ pub enum Subcommands {
         #[structopt(long, short, help = "the encoded output, in hex format")]
         input: bool,
     },
+    #[structopt(name = "abi-encode")]
+    #[structopt(
+        help = "ABI encodes the given arguments with the function signature, excluidng the selector"
+    )]
+    AbiEncode {
+        #[structopt(help = "the function signature")]
+        sig: String,
+        #[structopt(help = "the list of function arguments")]
+        args: Vec<String>,
+    },
     #[structopt(name = "4byte")]
     #[structopt(about = "Fetches function signatures given the selector from 4byte.directory")]
     FourByte {