From 9dae25f817648635d39761b57cf2474e4abe7787 Mon Sep 17 00:00:00 2001
From: Roman Dvorkin <121502696+rdvorkin@users.noreply.github.com>
Date: Thu, 21 Sep 2023 18:04:15 +0300
Subject: [PATCH] feat: always try to fetch optimistic update when starting lc
 (#5977)

* feat: Always try to fetch optimistic update when starting lc

Currently fetching an optimistic update at client start happens only if a sync is needed.
The proposed change tries to fetch an optimistic update even if no sync is needed, e.g. the client was initialized with a recent checkpoint

* Move the update fetching to the correct place
---
 packages/light-client/src/index.ts | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/packages/light-client/src/index.ts b/packages/light-client/src/index.ts
index 67dc86762ede..b38cc66894ae 100644
--- a/packages/light-client/src/index.ts
+++ b/packages/light-client/src/index.ts
@@ -242,6 +242,13 @@ export class Lightclient {
           await new Promise((r) => setTimeout(r, ON_ERROR_RETRY_MS));
           continue;
         }
+      }
+
+      // After successfully syncing, track head if not already
+      if (this.runStatus.code !== RunStatusCode.started) {
+        const controller = new AbortController();
+        this.updateRunStatus({code: RunStatusCode.started, controller});
+        this.logger.debug("Started tracking the head");
 
         // Fetch latest optimistic head to prevent a potential 12 seconds lag between syncing and getting the first head,
         // Don't retry, this is a non-critical UX improvement
@@ -251,13 +258,6 @@ export class Lightclient {
         } catch (e) {
           this.logger.error("Error fetching getLatestHeadUpdate", {currentPeriod}, e as Error);
         }
-      }
-
-      // After successfully syncing, track head if not already
-      if (this.runStatus.code !== RunStatusCode.started) {
-        const controller = new AbortController();
-        this.updateRunStatus({code: RunStatusCode.started, controller});
-        this.logger.debug("Started tracking the head");
 
         this.transport.onOptimisticUpdate(this.processOptimisticUpdate.bind(this));
         this.transport.onFinalityUpdate(this.processFinalizedUpdate.bind(this));