Fix Signal quote debounce target selection

extensions/mattermost/src/mattermost/monitor.ts

@@ -159,7 +159,7 @@ function channelChatType(kind: ChatType): "direct" | "group" | "channel" {
 
 export function resolveMattermostReplyRootId(params: {
   threadRootId?: string;
-  replyToId?: string;
+  replyToId?: string | null;
 }): string | undefined {
   const threadRootId = params.threadRootId?.trim();
   if (threadRootId) {

extensions/signal/src/monitor/event-handler.quote.test.ts

@@ -101,6 +101,64 @@ describe("signal quote reply handling", () => {
     expect(String(ctx?.Body ?? "")).toContain("[Quoting +15550003333 id:1700000000000]");
   });
 
+  it("uses the latest quote target when debouncing rapid quoted Signal replies", async () => {
+    vi.useFakeTimers();
+    try {
+      const handler = createQuoteHandler({
+        // oxlint-disable-next-line typescript/no-explicit-any
+        cfg: { messages: { inbound: { debounceMs: 25 } } } as any,
+      });
+
+      await handler(
+        createSignalReceiveEvent({
+          sourceNumber: "+15550002222",
+          sourceName: "Bob",
+          timestamp: 1700000000001,
+          dataMessage: {
+            message: "First chunk",
+            quote: {
+              id: 1700000000000,
+              authorNumber: "+15550003333",
+              text: "First quoted message",
+            },
+          },
+        }),
+      );
+      await handler(
+        createSignalReceiveEvent({
+          sourceNumber: "+15550002222",
+          sourceName: "Bob",
+          timestamp: 1700000000002,
+          dataMessage: {
+            message: "Second chunk",
+            quote: {
+              id: 1700000000009,
+              authorNumber: "+15550004444",
+              text: "Second quoted message",
+            },
+          },
+        }),
+      );
+
+      expect(dispatchInboundMessageMock).not.toHaveBeenCalled();
+
+      await vi.advanceTimersByTimeAsync(30);
+      await vi.waitFor(() => {
+        expect(dispatchInboundMessageMock).toHaveBeenCalledTimes(1);
+      });
+
+      const ctx = getCapturedCtx();
+      expect(ctx?.BodyForAgent).toBe("First chunk\\nSecond chunk");
+      expect(ctx?.ReplyToId).toBe("1700000000009");
+      expect(ctx?.ReplyToBody).toBe("Second quoted message");
+      expect(ctx?.ReplyToSender).toBe("+15550004444");
+      expect(String(ctx?.Body ?? "")).toContain("[Quoting +15550004444 id:1700000000009]");
+      expect(String(ctx?.Body ?? "")).not.toContain("[Quoting +15550003333 id:1700000000000]");
+    } finally {
+      vi.useRealTimers();
+    }
+  });
+
   it("keeps quote-only replies and exposes the replied-message context block", async () => {
     const handler = createQuoteHandler();
 

extensions/signal/src/monitor/event-handler.ts

@@ -476,8 +476,11 @@ export function createSignalEventHandler(deps: SignalEventHandlerDeps) {
       if (!combinedText.trim()) {
         return;
       }
-      // Preserve quoteTarget from the earliest entry that has one
-      const earliestQuoteTarget = entries.find((entry) => entry.quoteTarget)?.quoteTarget;
+      // Preserve quoteTarget from the latest entry that has one so the reply
+      // target matches the newest text in the merged body.
+      const latestQuoteTarget = entries
+        .toReversed()
+        .find((entry) => entry.quoteTarget)?.quoteTarget;
       await handleSignalInboundMessage({
         ...last,
         bodyText: combinedText,
@@ -485,7 +488,7 @@ export function createSignalEventHandler(deps: SignalEventHandlerDeps) {
         mediaType: undefined,
         mediaPaths: undefined,
         mediaTypes: undefined,
-        quoteTarget: earliestQuoteTarget ?? last.quoteTarget,
+        quoteTarget: latestQuoteTarget ?? last.quoteTarget,
       });
     },
     onError: (err) => {

src/plugins/loader.test.ts

@@ -1,7 +1,6 @@
 import fs from "node:fs";
 import os from "node:os";
 import path from "node:path";
-import { pathToFileURL } from "node:url";
 import { afterAll, afterEach, describe, expect, it, vi } from "vitest";
 import { emitDiagnosticEvent, resetDiagnosticEventsForTest } from "../infra/diagnostic-events.js";
 import { withEnv } from "../test-utils/env.js";
@@ -3262,7 +3261,7 @@ module.exports = {
     expect(record?.status).toBe("loaded");
   });
 
-  it("supports legacy plugins importing monolithic plugin-sdk root", async () => {
+  it("supports legacy plugins importing monolithic plugin-sdk root", () => {
     useNoBundledPlugins();
     const plugin = writePlugin({
       id: "legacy-root-import",