fix(slack): keep progress drafts in one message

steipete · mycarrysun · steipete · commit 947a71931bef · 2026-05-31T16:53:01.000+01:00
Keep Slack progress-mode drafts on one rolling preview message across assistant and reasoning boundaries while preserving boundary cleanup and the latest visible tool-progress lines. Partial/replace modes still start a fresh draft at assistant boundaries.

Co-authored-by: Mike Harrison &lt;mike@nextwebtoday.com&gt;
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
@@ -2179,7 +2179,7 @@ describe("dispatchPreparedSlackMessage preview fallback", () => {
       }),
     );
 
-    expect(draftStream.forceNewMessage).toHaveBeenCalledTimes(1);
+    expect(draftStream.forceNewMessage).not.toHaveBeenCalled();
     expect(draftStream.update).toHaveBeenLastCalledWith({
       text: ["Shelling", "• tool one", "• tool two"].join("\n"),
       blocks: [
@@ -2207,6 +2207,48 @@ describe("dispatchPreparedSlackMessage preview fallback", () => {
     expect(deliverRepliesMock).not.toHaveBeenCalled();
   });
 
+  it("preserves text Slack progress lines after a draft boundary status update", async () => {
+    const draftStream = createDraftStreamStub();
+    createSlackDraftStreamMock.mockReturnValueOnce(draftStream);
+    mockedSlackStreamingMode = "progress";
+    mockedSlackDraftMode = "status_final";
+    mockedDispatchSequence = [];
+    mockedReplyOptionEvents = [
+      { kind: "item", progressText: "tool one" },
+      { kind: "item", progressText: "tool two" },
+      { kind: "assistant_start" },
+      { kind: "partial", text: "partial answer" },
+    ];
+
+    await dispatchPreparedSlackMessage(
+      createPreparedSlackMessage({
+        accountConfig: { streaming: { progress: { label: "Working" } } },
+      }),
+    );
+
+    expect(draftStream.forceNewMessage).not.toHaveBeenCalled();
+    expect(draftStream.update).toHaveBeenLastCalledWith(
+      ["Working", "• tool one", "• tool two"].join("\n"),
+    );
+  });
+
+  it("forces a new draft message on assistant boundaries in partial mode", async () => {
+    const draftStream = createDraftStreamStub();
+    createSlackDraftStreamMock.mockReturnValueOnce(draftStream);
+    mockedSlackStreamingMode = "partial";
+    mockedSlackDraftMode = "replace";
+    mockedDispatchSequence = [];
+    mockedReplyOptionEvents = [
+      { kind: "partial", text: "first chunk" },
+      { kind: "assistant_start" },
+      { kind: "partial", text: "second chunk" },
+    ];
+
+    await dispatchPreparedSlackMessage(createPreparedSlackMessage({}));
+
+    expect(draftStream.forceNewMessage).toHaveBeenCalledTimes(1);
+  });
+
   it("can hide raw Slack command progress text by config", async () => {
     const draftStream = createDraftStreamStub();
     createSlackDraftStreamMock.mockReturnValueOnce(draftStream);
diff --git a/extensions/slack/src/monitor/message-handler/dispatch.ts b/extensions/slack/src/monitor/message-handler/dispatch.ts
@@ -1307,7 +1307,7 @@ export async function dispatchPreparedSlackMessage(prepared: PreparedSlackMessag
       return;
     }
     const progressLines =
-      useRichProgressDraft && previewToolProgressLines.length === 0
+      previewToolProgressLines.length === 0
         ? lastNonEmptyPreviewToolProgressLines
         : previewToolProgressLines;
     const previewText = formatChannelProgressDraftText({
@@ -1610,7 +1610,10 @@ export async function dispatchPreparedSlackMessage(prepared: PreparedSlackMessag
   const onDraftBoundary = !shouldUseDraftStream
     ? undefined
     : async () => {
-        if (hasStreamedMessage) {
+        // Progress drafts are one rolling message that's finalized in place.
+        // Keep boundary cleanup, but don't clear messageId or the next update
+        // posts a new draft instead of editing the existing preview.
+        if (hasStreamedMessage && streamMode !== "status_final") {
           draftStream?.forceNewMessage();
           hasStreamedMessage = false;
           appendRenderedText = "";
