diff --git a/rust/Cargo.lock b/rust/Cargo.lock
index 353cc1fba..41fff6412 100644
--- a/rust/Cargo.lock
+++ b/rust/Cargo.lock
@@ -1835,10 +1835,12 @@ dependencies = [
  "log",
  "optics-base",
  "optics-core",
+ "optics-test",
  "serde 1.0.123",
  "serde_json",
  "thiserror",
  "tokio",
+ "tokio-test",
  "tracing",
  "tracing-futures",
  "tracing-subscriber",
diff --git a/rust/optics-test/src/mocks/replica.rs b/rust/optics-test/src/mocks/replica.rs
index ec9a2ce50..84be7e600 100644
--- a/rust/optics-test/src/mocks/replica.rs
+++ b/rust/optics-test/src/mocks/replica.rs
@@ -14,52 +14,52 @@ use optics_core::{
 mock! {
     pub ReplicaContract {
         // Replica
-        fn _destination_domain(&self) -> u32 {}
+        pub fn _destination_domain(&self) -> u32 {}
 
-        fn _next_pending(&self) -> Result<Option<(H256, U256)>, ChainCommunicationError> {}
+        pub fn _next_pending(&self) -> Result<Option<(H256, U256)>, ChainCommunicationError> {}
 
-        fn _can_confirm(&self) -> Result<bool, ChainCommunicationError> {}
+        pub fn _can_confirm(&self) -> Result<bool, ChainCommunicationError> {}
 
-        fn _confirm(&self) -> Result<TxOutcome, ChainCommunicationError> {}
+        pub fn _confirm(&self) -> Result<TxOutcome, ChainCommunicationError> {}
 
-        fn _previous_root(&self) -> Result<H256, ChainCommunicationError> {}
+        pub fn _previous_root(&self) -> Result<H256, ChainCommunicationError> {}
 
-        fn _last_processed(&self) -> Result<U256, ChainCommunicationError> {}
+        pub fn _last_processed(&self) -> Result<U256, ChainCommunicationError> {}
 
-        fn _prove(&self, proof: &Proof) -> Result<TxOutcome, ChainCommunicationError> {}
+        pub fn _prove(&self, proof: &Proof) -> Result<TxOutcome, ChainCommunicationError> {}
 
-        fn _process(&self, message: &StampedMessage) -> Result<TxOutcome, ChainCommunicationError> {}
+        pub fn _process(&self, message: &StampedMessage) -> Result<TxOutcome, ChainCommunicationError> {}
 
-        fn _prove_and_process(
+        pub fn _prove_and_process(
             &self,
             message: &StampedMessage,
             proof: &Proof,
         ) -> Result<TxOutcome, ChainCommunicationError> {}
 
         // Common
-        fn _name(&self) -> &str {}
+        pub fn _name(&self) -> &str {}
 
-        fn _status(&self, txid: H256) -> Result<Option<TxOutcome>, ChainCommunicationError> {}
+        pub fn _status(&self, txid: H256) -> Result<Option<TxOutcome>, ChainCommunicationError> {}
 
-        fn _updater(&self) -> Result<H256, ChainCommunicationError> {}
+        pub fn _updater(&self) -> Result<H256, ChainCommunicationError> {}
 
-        fn _state(&self) -> Result<State, ChainCommunicationError> {}
+        pub fn _state(&self) -> Result<State, ChainCommunicationError> {}
 
-        fn _current_root(&self) -> Result<H256, ChainCommunicationError> {}
+        pub fn _current_root(&self) -> Result<H256, ChainCommunicationError> {}
 
-        fn _signed_update_by_old_root(
+        pub fn _signed_update_by_old_root(
             &self,
             old_root: H256,
         ) -> Result<Option<SignedUpdate>, ChainCommunicationError> {}
 
-        fn _signed_update_by_new_root(
+        pub fn _signed_update_by_new_root(
             &self,
             new_root: H256,
         ) -> Result<Option<SignedUpdate>, ChainCommunicationError> {}
 
-        fn _update(&self, update: &SignedUpdate) -> Result<TxOutcome, ChainCommunicationError> {}
+        pub fn _update(&self, update: &SignedUpdate) -> Result<TxOutcome, ChainCommunicationError> {}
 
-        fn _double_update(
+        pub fn _double_update(
             &self,
             double: &DoubleUpdate,
         ) -> Result<TxOutcome, ChainCommunicationError> {}
diff --git a/rust/relayer/Cargo.toml b/rust/relayer/Cargo.toml
index c0ba090e5..4853114fb 100644
--- a/rust/relayer/Cargo.toml
+++ b/rust/relayer/Cargo.toml
@@ -21,3 +21,7 @@ tracing-subscriber = "0.2.15"
 
 optics-core = { path = "../optics-core" }
 optics-base = { path = "../optics-base" }
+
+[dev-dependencies]
+tokio-test = "0.4.0"
+optics-test = { path = "../optics-test" }
diff --git a/rust/relayer/src/relayer.rs b/rust/relayer/src/relayer.rs
index 5ed9aa00f..19dc34e9c 100644
--- a/rust/relayer/src/relayer.rs
+++ b/rust/relayer/src/relayer.rs
@@ -39,7 +39,7 @@ impl Relayer {
     }
 
     #[tracing::instrument(err)]
-    async fn poll_updates(home: Arc<Homes>, replica: Arc<Replicas>) -> Result<()> {
+    async fn poll_and_relay_update(home: Arc<Homes>, replica: Arc<Replicas>) -> Result<()> {
         // Get replica's current root
         let old_root = replica.current_root().await?;
 
@@ -55,7 +55,7 @@ impl Relayer {
     }
 
     #[tracing::instrument(err)]
-    async fn poll_confirms(replica: Arc<Replicas>) -> Result<()> {
+    async fn poll_confirm(replica: Arc<Replicas>) -> Result<()> {
         // Check for pending update that can be confirmed
         let can_confirm = replica.can_confirm().await?;
 
@@ -99,8 +99,8 @@ impl OpticsAgent for Relayer {
 
             loop {
                 let (updated, confirmed) = tokio::join!(
-                    Self::poll_updates(home.clone(), replica.clone()),
-                    Self::poll_confirms(replica.clone())
+                    Self::poll_and_relay_update(home.clone(), replica.clone()),
+                    Self::poll_confirm(replica.clone())
                 );
 
                 if let Err(ref e) = updated {
@@ -116,3 +116,117 @@ impl OpticsAgent for Relayer {
         })
     }
 }
+
+#[cfg(test)]
+mod test {
+    use ethers::{core::types::H256, prelude::LocalWallet};
+    use std::sync::Arc;
+
+    use super::*;
+    use optics_core::{traits::TxOutcome, SignedUpdate, Update};
+    use optics_test::mocks::{MockHomeContract, MockReplicaContract};
+
+    #[tokio::test]
+    async fn polls_and_relays_updates() {
+        let signer: LocalWallet =
+            "1111111111111111111111111111111111111111111111111111111111111111"
+                .parse()
+                .unwrap();
+
+        let first_root = H256::from([1; 32]);
+        let second_root = H256::from([2; 32]);
+
+        let signed_update = Update {
+            origin_domain: 1,
+            previous_root: first_root,
+            new_root: second_root,
+        }
+        .sign_with(&signer)
+        .await
+        .expect("!sign");
+
+        let mut mock_home = MockHomeContract::new();
+        let mut mock_replica = MockReplicaContract::new();
+
+        {
+            let signed_update = signed_update.clone();
+            // home.signed_update_by_old_root(first_root) called once and
+            // returns mock value signed_update
+            mock_home
+                .expect__signed_update_by_old_root()
+                .withf(move |r: &H256| *r == first_root)
+                .times(1)
+                .return_once(move |_| Ok(Some(signed_update)));
+        }
+        {
+            let signed_update = signed_update.clone();
+            // replica.current_root called once and returns mock value
+            // first_root
+            mock_replica
+                .expect__current_root()
+                .times(1)
+                .returning(move || Ok(first_root));
+            // replica.update(signed_update) called once and returns
+            // mock default value
+            mock_replica
+                .expect__update()
+                .withf(move |s: &SignedUpdate| *s == signed_update)
+                .times(1)
+                .returning(|_| {
+                    Ok(TxOutcome {
+                        txid: H256::default(),
+                        executed: true,
+                    })
+                });
+        }
+
+        let mut home: Arc<Homes> = Arc::new(mock_home.into());
+        let mut replica: Arc<Replicas> = Arc::new(mock_replica.into());
+        Relayer::poll_and_relay_update(home.clone(), replica.clone())
+            .await
+            .expect("Should have returned Ok(())");
+
+        let mock_home = Arc::get_mut(&mut home).unwrap();
+        if let Homes::Mock(home) = mock_home {
+            home.checkpoint();
+        } else {
+            panic!("Home should be mock variant!");
+        }
+
+        let mock_replica = Arc::get_mut(&mut replica).unwrap();
+        if let Replicas::Mock(replica) = mock_replica {
+            replica.checkpoint();
+        } else {
+            panic!("Replica should be mock variant!");
+        }
+    }
+
+    #[tokio::test]
+    async fn confirms_updates() {
+        let mut mock_replica = MockReplicaContract::new();
+        // replica.can_confirm called once and returns mock true
+        mock_replica
+            .expect__can_confirm()
+            .times(1)
+            .returning(|| Ok(true));
+        // replica.confirm called once and returns mock default
+        mock_replica.expect__confirm().times(1).returning(|| {
+            Ok(TxOutcome {
+                txid: H256::default(),
+                executed: true,
+            })
+        });
+
+        let mut replica: Arc<Replicas> = Arc::new(mock_replica.into());
+        Relayer::poll_confirm(replica.clone())
+            .await
+            .expect("Should have returned Ok(())");
+
+        let mock_replica = Arc::get_mut(&mut replica).unwrap();
+        if let Replicas::Mock(replica) = mock_replica {
+            replica.checkpoint();
+        } else {
+            panic!("Replica should be mock variant!");
+        }
+    }
+}
diff --git a/rust/updater/src/updater.rs b/rust/updater/src/updater.rs
index a9fbb7490..d55c5e04e 100644
--- a/rust/updater/src/updater.rs
+++ b/rust/updater/src/updater.rs
@@ -121,7 +121,7 @@ mod test {
     use optics_test::mocks::MockHomeContract;
 
     #[tokio::test]
-    async fn polls_and_signs_update() {
+    async fn polls_and_submits_update() {
         let signer: LocalWallet =
             "1111111111111111111111111111111111111111111111111111111111111111"
                 .parse()
@@ -135,7 +135,7 @@ mod test {
             previous_root,
             new_root,
         };
-        let signed_update = update.sign_with(&signer).await.unwrap();
+        let signed_update = update.sign_with(&signer).await.expect("!sign");
 
         let mut mock_home = MockHomeContract::new();