testing(lightclient): Mocking DA layer (#348)

* feat: mock da

* update

* update

* fix

* cleaner setup

* another (failing) case

* fixing bugs

* new test cases, some fixes

* ignoring too old headers

* simplifications

* new test cases

* improvements

Author: distractedm1nd

Cargo.toml

@@ -184,7 +184,7 @@ sha2-v0-10-8 = { git = "https://github.com/sp1-patches/RustCrypto-hashes", packa
 curve25519-dalek-ng = { git = "https://github.com/sp1-patches/curve25519-dalek-ng", tag = "patch-4.1.1-sp1-4.0.0" }
 p256 = { git = "https://github.com/sp1-patches/elliptic-curves", tag = "patch-p256-13.2-sp1-4.1.0" }
 k256 = { git = "https://github.com/sp1-patches/elliptic-curves", tag = "patch-k256-13.4-sp1-4.1.0" }
-celestia-types = {  git = "https://github.com/deltadevsde/lumina.git"  }
+celestia-types = { git = "https://github.com/deltadevsde/lumina.git" }
 lumina-node = { git = "https://github.com/deltadevsde/lumina.git" }
 
 [workspace.features]

crates/da/src/celestia/light_client.rs

@@ -22,11 +22,7 @@ use lumina_node::{blockstore::IndexedDbBlockstore, store::IndexedDbStore};
 use lumina_node::NodeBuilder;
 
 #[cfg(not(target_arch = "wasm32"))]
-use {
-    blockstore::EitherBlockstore,
-    redb::Database,
-    tokio::task::spawn_blocking,
-};
+use {blockstore::EitherBlockstore, redb::Database, tokio::task::spawn_blocking};
 
 #[cfg(feature = "uniffi")]
 use lumina_node_uniffi::types::NodeConfig;
@@ -183,6 +179,7 @@ impl LightDataAvailabilityLayer for LightClientConnection {
             Err(e) => return Err(anyhow!("Failed to fetch header: {}", e)),
         };
 
+        // TODO(Zombeescott): Implement retries + timeout
         match node.request_all_blobs(&header, self.snark_namespace, None).await {
             Ok(blobs) => {
                 let epochs: Vec<VerifiableEpoch> = blobs

crates/da/src/events.rs

@@ -1,4 +1,4 @@
-use lumina_node::events::{NodeEvent, EventSubscriber as LuminaEventSub};
+use lumina_node::events::{EventSubscriber as LuminaEventSub, NodeEvent};
 use prism_common::digest::Digest;
 use serde::Serialize;
 use std::{fmt, sync::Arc};
@@ -14,7 +14,9 @@ const EVENT_CHANNEL_CAPACITY: usize = 1024;
 #[serde(tag = "type")]
 #[serde(rename_all = "snake_case")]
 pub enum PrismEvent {
-    SyncStarted { height: u64 },
+    Ready,
+    BackwardsSyncStarted { height: u64 },
+    BackwardsSyncCompleted { height: Option<u64> },
     UpdateDAHeight { height: u64 },
     EpochVerificationStarted { height: u64 },
     EpochVerified { height: u64 },
@@ -35,8 +37,21 @@ pub enum PrismEvent {
 impl fmt::Display for PrismEvent {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
-            PrismEvent::SyncStarted { height } => {
-                write!(f, "Starting sync at height {}", height)
+            PrismEvent::Ready => {
+                write!(
+                    f,
+                    "Node is ready to start sync and listening for incoming headers"
+                )
+            }
+            PrismEvent::BackwardsSyncStarted { height } => {
+                write!(f, "Starting backwards sync at height {}", height)
+            }
+            PrismEvent::BackwardsSyncCompleted { height } => {
+                write!(
+                    f,
+                    "Backwards sync complete, found epoch: {}",
+                    height.is_some()
+                )
             }
             PrismEvent::UpdateDAHeight { height } => {
                 write!(f, "Updated DA height to {}", height)

crates/da/src/lib.rs

@@ -66,6 +66,7 @@ impl From<EpochCommitments> for (Digest, Digest) {
 
 /// `VerifiableStateTransition` is a trait wrapper around `FinalizedEpoch` that allows for mocking.
 /// The only concrete implementation of this trait is by `FinalizedEpoch`.
+#[automock]
 pub trait VerifiableStateTransition: Send {
     fn verify(
         &self,

crates/node_types/lightclient/src/lib.rs

@@ -1,2 +1,5 @@
 pub mod lightclient;
 pub use lightclient::LightClient;
+
+#[cfg(test)]
+mod tests;