Homogenize ConnectionReader functions (#349)

* ConnectionReader.connection_end returns owned val

* Removed redundant clones, updated changelog; ready to fix #347.

Co-authored-by: CharlyCst <castes.ch@gmail.com>

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Unreleased Changes
 
+Special thanks to external contributors for this release: @CharlyCst ([#347]).
+
 ### FEATURES
 
 - [changelog] Added "unreleased" section in `CHANGELOG.MD` to help streamline releases ([#274])
@@ -17,8 +19,10 @@
 ### IMPROVEMENTS
 
 - [relayer-cli] Split tasks spawned by CLI commands into their own modules ([#331])
+- [modules] Homogenize ConnectionReader trait so that all functions return owned objects ([#347])
 
 [#331]: https://github.com/informalsystems/ibc-rs/pulls/331
+[#347]: https://github.com/informalsystems/ibc-rs/issues/347
 
 ## v0.0.4
 *October 19, 2020*

modules/src/ics03_connection/context.rs

@@ -13,7 +13,7 @@ use crate::Height;
 /// A context supplying all the necessary read-only dependencies for processing any `ConnectionMsg`.
 pub trait ConnectionReader {
     /// Returns the ConnectionEnd for the given identifier `conn_id`.
-    fn connection_end(&self, conn_id: &ConnectionId) -> Option<&ConnectionEnd>;
+    fn connection_end(&self, conn_id: &ConnectionId) -> Option<ConnectionEnd>;
 
     /// Returns the ClientState for the given identifier `client_id`.
     fn client_state(&self, client_id: &ClientId) -> Option<AnyClientState>;

modules/src/ics03_connection/handler/conn_open_ack.rs

@@ -35,7 +35,7 @@ pub(crate) fn process(
                 || old_conn_end.counterparty().connection_id() == msg.counterparty_connection_id();
 
             if state_is_consistent && counterparty_matches {
-                Ok(old_conn_end.clone())
+                Ok(old_conn_end)
             } else {
                 // Old connection end is in incorrect state, propagate the error.
                 Err(Into::<Error>::into(Kind::ConnectionMismatch(

modules/src/ics03_connection/handler/conn_open_confirm.rs

@@ -25,7 +25,7 @@ pub(crate) fn process(
                     msg.connection_id().clone(),
                 )))
             } else {
-                Ok(old_conn_end.clone())
+                Ok(old_conn_end)
             }
         }
         None => {

modules/src/ics03_connection/handler/conn_open_try.rs

@@ -37,7 +37,7 @@ pub(crate) fn process(
                 && old_conn_end.client_id_matches(msg.client_id())
             {
                 // A ConnectionEnd already exists and all validation passed.
-                Ok(old_conn_end.clone())
+                Ok(old_conn_end)
             } else {
                 // A ConnectionEnd already exists and validation failed.
                 Err(Into::<Error>::into(

modules/src/mock_context.rs

@@ -202,8 +202,8 @@ impl MockContext {
 impl ICS26Context for MockContext {}
 
 impl ConnectionReader for MockContext {
-    fn connection_end(&self, cid: &ConnectionId) -> Option<&ConnectionEnd> {
-        self.connections.get(cid)
+    fn connection_end(&self, cid: &ConnectionId) -> Option<ConnectionEnd> {
+        self.connections.get(cid).cloned()
     }
 
     fn client_state(&self, client_id: &ClientId) -> Option<AnyClientState> {