Feat(cast): Add --parse-bytes32-address (#4746)

* Feat: Add --parse-bytes32-address

* Minor: removed out of context comment

* Changed error message

* Removed function to use inline code

* fix import

---------

Co-authored-by: Matthias Seitz <[email protected]>

cast/src/lib.rs

@@ -1283,7 +1283,7 @@ impl SimpleCast {
     pub fn parse_bytes32_string(s: &str) -> Result<String> {
         let s = strip_0x(s);
         if s.len() != 64 {
-            eyre::bail!("string not 32 bytes");
+            eyre::bail!("expected 64 byte hex-string, got {s}");
         }
 
         let bytes = hex::decode(s)?;
@@ -1293,6 +1293,25 @@ impl SimpleCast {
         Ok(parse_bytes32_string(&buffer)?.to_owned())
     }
 
+    /// Decodes checksummed address from bytes32 value
+    pub fn parse_bytes32_address(s: &str) -> Result<String> {
+        let s = strip_0x(s);
+        if s.len() != 64 {
+            eyre::bail!("expected 64 byte hex-string, got {s}");
+        }
+
+        let s = if let Some(stripped) = s.strip_prefix("000000000000000000000000") {
+            stripped
+        } else {
+            return Err(eyre::eyre!("Not convertible to address, there are non-zero bytes"))
+        };
+
+        let lowercase_address_string = format!("0x{s}");
+        let lowercase_address = Address::from_str(&lowercase_address_string)?;
+
+        Ok(ethers_core::utils::to_checksum(&lowercase_address, None))
+    }
+
     /// Decodes abi-encoded hex input or output
     ///
     /// # Example

cli/src/cast.rs

@@ -157,6 +157,10 @@ async fn main() -> eyre::Result<()> {
             let value = stdin::unwrap_line(bytes)?;
             println!("{}", SimpleCast::parse_bytes32_string(&value)?);
         }
+        Subcommands::ParseBytes32Address { bytes } => {
+            let value = stdin::unwrap_line(bytes)?;
+            println!("{}", SimpleCast::parse_bytes32_address(&value)?);
+        }
 
         // ABI encoding & decoding
         Subcommands::AbiDecode { sig, calldata, input } => {

cli/src/opts/cast.rs

@@ -822,6 +822,12 @@ pub enum Subcommands {
         /// The string to parse.
         bytes: Option<String>,
     },
+    #[clap(name = "--parse-bytes32-address")]
+    #[clap(about = "Parses a checksummed address from bytes32 encoding.")]
+    ParseBytes32Address {
+        #[clap(value_name = "BYTES")]
+        bytes: Option<String>,
+    },
 }
 
 /// CLI arguments for `cast --to-base`.

cli/tests/it/cast.rs

@@ -373,6 +373,16 @@ casttest!(cast_receipt_revert_reason, |_: TestProject, mut cmd: TestCommand| {
     assert!(output.contains("Transaction too old"));
 });
 
+// tests that `cast --parse-bytes32-address` command is working correctly.
+casttest!(parse_bytes32_address, |_: TestProject, mut cmd: TestCommand| {
+    cmd.args([
+        "--parse-bytes32-address",
+        "0x000000000000000000000000d8da6bf26964af9d7eed9e03e53415d37aa96045",
+    ]);
+    let output = cmd.stdout_lossy();
+    assert_eq!(output.trim(), "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045")
+});
+
 casttest!(cast_access_list, |_: TestProject, mut cmd: TestCommand| {
     let rpc = next_http_rpc_endpoint();
     cmd.args([