From c90a828d171c014da197b406ff6614fe4644b57d Mon Sep 17 00:00:00 2001
From: Vincent Koc <vincentkoc@ieee.org>
Date: Sun, 3 May 2026 16:48:35 -0700
Subject: [PATCH] fix(slack): skip empty progress refreshes

---
 .../dispatch.preview-fallback.test.ts            |  1 +
 .../src/monitor/message-handler/dispatch.ts      | 16 +++++++++-------
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/extensions/slack/src/monitor/message-handler/dispatch.preview-fallback.test.ts b/extensions/slack/src/monitor/message-handler/dispatch.preview-fallback.test.ts
index e27abfaddd6..bde86baa398 100644
--- a/extensions/slack/src/monitor/message-handler/dispatch.preview-fallback.test.ts
+++ b/extensions/slack/src/monitor/message-handler/dispatch.preview-fallback.test.ts
@@ -744,6 +744,7 @@ describe("dispatchPreparedSlackMessage preview fallback", () => {
     mockedReplyOptionEvents = [
       { kind: "item", progressText: "tool one" },
       { kind: "item", progressText: "tool two" },
+      { kind: "partial", text: "partial answer" },
     ];
 
     await dispatchPreparedSlackMessage(
diff --git a/extensions/slack/src/monitor/message-handler/dispatch.ts b/extensions/slack/src/monitor/message-handler/dispatch.ts
index 126ed919570..4b3f9225680 100644
--- a/extensions/slack/src/monitor/message-handler/dispatch.ts
+++ b/extensions/slack/src/monitor/message-handler/dispatch.ts
@@ -984,13 +984,15 @@ export async function dispatchPreparedSlackMessage(prepared: PreparedSlackMessag
       if (statusUpdateCount > 1 && statusUpdateCount % 4 !== 0) {
         return;
       }
-      draftStream?.update(
-        formatChannelProgressDraftText({
-          entry: account.config,
-          lines: previewToolProgressLines,
-          seed: progressSeed,
-        }),
-      );
+      const previewText = formatChannelProgressDraftText({
+        entry: account.config,
+        lines: previewToolProgressLines,
+        seed: progressSeed,
+      });
+      if (!previewText) {
+        return;
+      }
+      draftStream?.update(previewText);
       hasStreamedMessage = true;
       return;
     }