refactor: expose subscribe on the base client, with optional callback and call on child clients

src/baseClient.ts

@@ -85,6 +85,21 @@ export default abstract class BaseClient {
     this.syncMutex.release();
   }
 
+  protected async subscribe(callback?: (ei: ExecutionInfo) => void) {
+    setInterval(async () => {
+      try {
+        await this._sync();
+        const ei = await this.getLatestExecution();
+        if (ei && ei.blockHash !== this.latestBlockHash) {
+          this.latestBlockHash = ei.blockHash;
+          return await callback?.(ei);
+        }
+      } catch (e) {
+        console.error(e);
+      }
+    }, POLLING_DELAY);
+  }
+
   public get store(): IStore {
     return this.options.store as IStore;
   }

src/client/client.ts

@@ -101,21 +101,6 @@ export default class Client extends BaseClient {
     return this.getCommittee(currentPeriod, lastCommitteeHash);
   }
 
-  private async subscribe(callback: (ei: ExecutionInfo) => void) {
-    setInterval(async () => {
-      try {
-        await this._sync();
-        const ei = await this.getLatestExecution();
-        if (ei && ei.blockHash !== this.latestBlockHash) {
-          this.latestBlockHash = ei.blockHash;
-          return await callback(ei);
-        }
-      } catch (e) {
-        console.error(e);
-      }
-    }, POLLING_DELAY);
-  }
-
   private async getCommittee(
     period: number,
     expectedCommitteeHash: Uint8Array | null,

src/node/client.ts

@@ -28,6 +28,11 @@ interface Config extends BaseClientOptions {
 }
 
 export default class Client extends BaseClient {
+  async sync(): Promise<void> {
+    await super.sync();
+
+    this.subscribe();
+  }
   private beaconUrl: string;
   private blockCache = new NodeCache({ stdTTL: 60 * 60 * 12 });
   private blockHashCache = new NodeCache({ stdTTL: 60 * 60 * 12 });