Handle empty upgrade metadata in GetLightdInfo

packages/zaino-state/src/backends.rs

@@ -3,3 +3,29 @@
 pub mod fetch;
 
 pub mod state;
+
+fn latest_network_upgrade(
+    upgrades: &indexmap::IndexMap<
+        zebra_rpc::methods::ConsensusBranchIdHex,
+        zebra_rpc::methods::NetworkUpgradeInfo,
+    >,
+) -> Result<&zebra_rpc::methods::NetworkUpgradeInfo, tonic::Status> {
+    upgrades.last().map(|(_, upgrade)| upgrade).ok_or_else(|| {
+        tonic::Status::failed_precondition("validator returned no network upgrade metadata")
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn latest_network_upgrade_rejects_empty_metadata() {
+        let upgrades = indexmap::IndexMap::new();
+        let err = super::latest_network_upgrade(&upgrades).expect_err("empty upgrades must fail");
+
+        assert_eq!(err.code(), tonic::Code::FailedPrecondition);
+        assert_eq!(
+            err.message(),
+            "validator returned no network upgrade metadata"
+        );
+    }
+}

packages/zaino-state/src/backends/fetch.rs

@@ -1957,15 +1957,12 @@ impl LightWalletIndexer for FetchServiceSubscriber {
         )
         .to_string();
 
-        let nu_info = blockchain_info
-            .upgrades()
-            .last()
-            .expect("Expected validator to have a consenus activated.")
-            .1
+        let latest_upgrade = super::latest_network_upgrade(blockchain_info.upgrades())
+            .map_err(FetchServiceError::TonicStatusError)?
             .into_parts();
 
-        let nu_name = nu_info.0;
-        let nu_height = nu_info.1;
+        let nu_name = latest_upgrade.0;
+        let nu_height = latest_upgrade.1;
 
         Ok(LightdInfo {
             version: self.data.build_info().version(),

packages/zaino-state/src/backends/state.rs

@@ -2609,15 +2609,12 @@ impl LightWalletIndexer for StateServiceSubscriber {
         )
         .to_string();
 
-        let nu_info = blockchain_info
-            .upgrades()
-            .last()
-            .expect("Expected validator to have a consenus activated.")
-            .1
+        let latest_upgrade = super::latest_network_upgrade(blockchain_info.upgrades())
+            .map_err(StateServiceError::TonicStatusError)?
             .into_parts();
 
-        let nu_name = nu_info.0;
-        let nu_height = nu_info.1;
+        let nu_name = latest_upgrade.0;
+        let nu_height = latest_upgrade.1;
 
         Ok(LightdInfo {
             version: self.data.build_info().version(),