Fix for chain_version parsing when chain identifier has multiple da…

…shes (#884)

* Solution: use the last digit (fix #878) (#879)

use expect

Co-authored-by: jongwhan lee <leejw51@gmail.com>

* Doc tests and FMT

* Changelog

Co-authored-by: Jongwhan Lee <51560997+leejw51crypto@users.noreply.github.com>
Co-authored-by: jongwhan lee <leejw51@gmail.com>

CHANGELOG.md

@@ -1,5 +1,8 @@
 ## Unreleased
 
+Special thanks to external contributors:
+Jongwhan Lee (@leejw51crypto) ([#878]).
+
 > [TODO: high level summary]
 
 ### FEATURES
@@ -18,6 +21,9 @@
 
 ### BUG FIXES
 
+- [ibc]
+  - Fix parsing in `chain_version` when chain identifier has multiple dashes ([#878])
+
 - [ibc-relayer]
   - Fix pagination in gRPC query for clients ([#811])
   - Fix relayer crash when hermes starts in the same time as packets are being sent ([#851])
@@ -41,6 +47,7 @@
 [#854]: https://github.com/informalsystems/ibc-rs/issues/854
 [#861]: https://github.com/informalsystems/ibc-rs/issues/861
 [#869]: https://github.com/informalsystems/ibc-rs/issues/869
+[#878]: https://github.com/informalsystems/ibc-rs/issues/878
 
 
 ## v0.2.0

modules/src/ics24_host/identifier.rs

@@ -53,13 +53,25 @@ impl ChainId {
     }
 
     /// Extract the version from the given chain identifier.
+    /// ```
+    /// use ibc::ics24_host::identifier::ChainId;
+    ///
+    /// assert_eq!(ChainId::chain_version("chain--a-0"), 0);
+    /// assert_eq!(ChainId::chain_version("ibc-10"), 10);
+    /// assert_eq!(ChainId::chain_version("cosmos-hub-97"), 97);
+    /// assert_eq!(ChainId::chain_version("testnet-helloworld-2"), 2);
+    /// ```
     pub fn chain_version(chain_id: &str) -> u64 {
         if !ChainId::is_epoch_format(chain_id) {
             return 0;
         }
 
         let split: Vec<_> = chain_id.split('-').collect();
-        split[1].parse().unwrap_or(0)
+        split
+            .last()
+            .expect("get revision number from chain_id")
+            .parse()
+            .unwrap_or(0)
     }
 
     /// is_epoch_format() checks if a chain_id is in the format required for parsing epochs