Remove Header trait (#617) from IBC crate. (#730)

* Remove Header trait (#617) from IBC crate.

* Remove query_latest_header() definition from MockContext and related code cleanup.

.changelog/unreleased/improvement/617-remove-header-trait.md

@@ -0,0 +1 @@
+- Remove Header trait ([#617](https://github.com/cosmos/ibc-rs/issues/617))

crates/ibc/src/clients/ics07_tendermint/header.rs

@@ -48,6 +48,10 @@ impl Display for Header {
 }
 
 impl Header {
+    pub fn timestamp(&self) -> Timestamp {
+        self.signed_header.header.time.into()
+    }
+
     pub fn height(&self) -> Height {
         Height::new(
             ChainId::chain_version(self.signed_header.header.chain_id.as_str()),
@@ -131,16 +135,6 @@ impl Header {
     }
 }
 
-impl crate::core::ics02_client::header::Header for Header {
-    fn height(&self) -> Height {
-        self.height()
-    }
-
-    fn timestamp(&self) -> Timestamp {
-        self.signed_header.header.time.into()
-    }
-}
-
 impl Protobuf<RawHeader> for Header {}
 
 impl TryFrom<RawHeader> for Header {

crates/ibc/src/core/ics02_client/mod.rs

@@ -6,6 +6,5 @@ pub mod consensus_state;
 pub mod error;
 pub mod events;
 pub mod handler;
-pub mod header;
 pub mod height;
 pub mod msgs;

crates/ibc/src/mock/context.rs

@@ -30,7 +30,6 @@ use crate::core::ics02_client::client_state::ClientState;
 use crate::core::ics02_client::client_type::ClientType;
 use crate::core::ics02_client::consensus_state::ConsensusState;
 use crate::core::ics02_client::error::ClientError;
-use crate::core::ics02_client::header::Header;
 use crate::core::ics03_connection::connection::ConnectionEnd;
 use crate::core::ics03_connection::error::ConnectionError;
 use crate::core::ics04_channel::channel::ChannelEnd;
@@ -600,6 +599,11 @@ impl MockContext {
     pub fn ibc_store_share(&self) -> Arc<Mutex<MockIbcStore>> {
         self.ibc_store.clone()
     }
+
+    pub fn query_latest_header(&self) -> Option<HostBlock> {
+        let block_ref = self.host_block(&self.host_height().unwrap());
+        block_ref.cloned()
+    }
 }
 
 type PortChannelIdMap<V> = BTreeMap<PortId, BTreeMap<ChannelId, V>>;
@@ -669,11 +673,6 @@ impl RelayerContext for MockContext {
         ValidationContext::client_state(self, client_id).ok()
     }
 
-    fn query_latest_header(&self) -> Option<Box<dyn Header>> {
-        let block_ref = self.host_block(&self.host_height().unwrap());
-        block_ref.cloned().map(Header::into_box)
-    }
-
     fn signer(&self) -> Signer {
         "0CDA3F47EF3C4906693B170EF650EB968C5F4B2C"
             .to_string()

crates/ibc/src/mock/header.rs

@@ -6,7 +6,6 @@ use ibc_proto::ibc::mock::Header as RawMockHeader;
 use ibc_proto::protobuf::Protobuf;
 
 use crate::core::ics02_client::error::ClientError;
-use crate::core::ics02_client::header::Header;
 use crate::core::timestamp::Timestamp;
 use crate::Height;
 
@@ -89,16 +88,6 @@ impl MockHeader {
     }
 }
 
-impl Header for MockHeader {
-    fn height(&self) -> Height {
-        self.height
-    }
-
-    fn timestamp(&self) -> Timestamp {
-        self.timestamp
-    }
-}
-
 impl Protobuf<Any> for MockHeader {}
 
 impl TryFrom<Any> for MockHeader {

crates/ibc/src/mock/host.rs

@@ -12,7 +12,6 @@ use crate::clients::ics07_tendermint::consensus_state::ConsensusState as TMConse
 use crate::clients::ics07_tendermint::header::TENDERMINT_HEADER_TYPE_URL;
 use crate::core::ics02_client::consensus_state::ConsensusState;
 use crate::core::ics02_client::error::ClientError;
-use crate::core::ics02_client::header::Header;
 use crate::core::ics24_host::identifier::ChainId;
 use crate::core::timestamp::Timestamp;
 use crate::mock::consensus_state::MockConsensusState;
@@ -181,13 +180,3 @@ impl From<HostBlock> for Any {
         }
     }
 }
-
-impl Header for HostBlock {
-    fn height(&self) -> Height {
-        HostBlock::height(self)
-    }
-
-    fn timestamp(&self) -> Timestamp {
-        HostBlock::timestamp(self)
-    }
-}

crates/ibc/src/mock/ics18_relayer/context.rs

@@ -1,7 +1,6 @@
 use crate::prelude::*;
 
 use crate::core::ics02_client::client_state::ClientState;
-use crate::core::ics02_client::header::Header;
 
 use crate::core::ics24_host::identifier::ClientId;
 use crate::core::ContextError;
@@ -21,17 +20,13 @@ pub trait RelayerContext {
     /// Wrapper over the `/abci_query?path=..` endpoint.
     fn query_client_full_state(&self, client_id: &ClientId) -> Option<Box<dyn ClientState>>;
 
-    /// Returns the most advanced header of this chain.
-    fn query_latest_header(&self) -> Option<Box<dyn Header>>;
-
     /// Temporary solution. Similar to `CosmosSDKChain::key_and_signer()` but simpler.
     fn signer(&self) -> Signer;
 }
 
 #[cfg(test)]
 mod tests {
     use crate::clients::ics07_tendermint::client_type as tm_client_type;
-    use crate::core::ics02_client::header::Header;
     use crate::core::ics02_client::msgs::update_client::MsgUpdateClient;
     use crate::core::ics02_client::msgs::ClientMsg;
     use crate::core::ics24_host::identifier::{ChainId, ClientId};
@@ -47,16 +42,12 @@ mod tests {
     use test_log::test;
     use tracing::debug;
 
-    fn downcast_header<H: Header>(h: &dyn Header) -> Option<&H> {
-        h.as_any().downcast_ref::<H>()
-    }
-
     /// Builds a `ClientMsg::UpdateClient` for a client with id `client_id` running on the `dest`
     /// context, assuming that the latest header on the source context is `src_header`.
     pub(crate) fn build_client_update_datagram<Ctx>(
         dest: &Ctx,
         client_id: &ClientId,
-        src_header: &dyn Header,
+        src_header: &HostBlock,
     ) -> Result<ClientMsg, RelayerError>
     where
         Ctx: RelayerContext,
@@ -90,7 +81,7 @@ mod tests {
         // Client on destination chain can be updated.
         Ok(ClientMsg::UpdateClient(MsgUpdateClient {
             client_id: client_id.clone(),
-            header: src_header.clone_into(),
+            header: (*src_header).clone().into(),
             signer: dest.signer(),
         }))
     }
@@ -141,7 +132,7 @@ mod tests {
             // - create the client update message with the latest header from A
             let a_latest_header = ctx_a.query_latest_header().unwrap();
             let client_msg_b_res =
-                build_client_update_datagram(&ctx_b, &client_on_b_for_a, a_latest_header.as_ref());
+                build_client_update_datagram(&ctx_b, &client_on_b_for_a, &a_latest_header);
 
             assert!(
                 client_msg_b_res.is_ok(),
@@ -173,18 +164,13 @@ mod tests {
             // Update client on chain A to latest height of B.
             // - create the client update message with the latest header from B
             // The test uses LightClientBlock that does not store the trusted height
-            let b_latest_header = ctx_b.query_latest_header().unwrap();
-            let b_latest_header: &HostBlock = downcast_header(b_latest_header.as_ref()).unwrap();
-            let mut b_latest_header = b_latest_header.clone();
+            let mut b_latest_header = ctx_b.query_latest_header().unwrap();
 
             let th = b_latest_header.height();
             b_latest_header.set_trusted_height(th.decrement().unwrap());
 
-            let client_msg_a_res = build_client_update_datagram(
-                &ctx_a,
-                &client_on_a_for_b,
-                b_latest_header.into_box().as_ref(),
-            );
+            let client_msg_a_res =
+                build_client_update_datagram(&ctx_a, &client_on_a_for_b, &b_latest_header);
 
             assert!(
                 client_msg_a_res.is_ok(),