refactor: centralize slack threading helpers

src/slack/monitor.ts

@@ -58,7 +58,13 @@ import type { RuntimeEnv } from "../runtime.js";
 import { resolveSlackAccount } from "./accounts.js";
 import { reactSlackMessage } from "./actions.js";
 import { sendMessageSlack } from "./send.js";
+import { resolveSlackThreadTargets } from "./threading.js";
 import { resolveSlackAppToken, resolveSlackBotToken } from "./token.js";
+import type {
+  SlackAppMentionEvent,
+  SlackFile,
+  SlackMessageEvent,
+} from "./types.js";
 
 export type MonitorSlackOpts = {
   botToken?: string;
@@ -71,45 +77,6 @@ export type MonitorSlackOpts = {
   slashCommand?: SlackSlashCommandConfig;
 };
 
-type SlackFile = {
-  id?: string;
-  name?: string;
-  mimetype?: string;
-  size?: number;
-  url_private?: string;
-  url_private_download?: string;
-};
-
-type SlackMessageEvent = {
-  type: "message";
-  user?: string;
-  bot_id?: string;
-  subtype?: string;
-  username?: string;
-  text?: string;
-  ts?: string;
-  thread_ts?: string;
-  event_ts?: string;
-  parent_user_id?: string;
-  channel: string;
-  channel_type?: "im" | "mpim" | "channel" | "group";
-  files?: SlackFile[];
-};
-
-type SlackAppMentionEvent = {
-  type: "app_mention";
-  user?: string;
-  bot_id?: string;
-  username?: string;
-  text?: string;
-  ts?: string;
-  thread_ts?: string;
-  event_ts?: string;
-  parent_user_id?: string;
-  channel: string;
-  channel_type?: "im" | "mpim" | "channel" | "group";
-};
-
 type SlackReactionEvent = {
   type: "reaction_added" | "reaction_removed";
   user?: string;
@@ -1102,12 +1069,10 @@ export async function monitorSlackProvider(opts: MonitorSlackOpts = {}) {
       );
     }
 
-    const incomingThreadTs = message.thread_ts;
-    const eventTs = message.event_ts;
-    const messageTs = message.ts ?? eventTs;
-    const replyThreadTs =
-      incomingThreadTs ?? (replyToMode === "all" ? messageTs : undefined);
-    const statusThreadTs = replyThreadTs ?? messageTs;
+    const { replyThreadTs, statusThreadTs } = resolveSlackThreadTargets({
+      message,
+      replyToMode,
+    });
     let didSetStatus = false;
     const onReplyStart = async () => {
       didSetStatus = true;

src/slack/threading.test.ts

@@ -0,0 +1,48 @@
+import { describe, expect, it } from "vitest";
+
+import { resolveSlackThreadTargets } from "./threading.js";
+
+describe("resolveSlackThreadTargets", () => {
+  it("threads replies when message is already threaded", () => {
+    const { replyThreadTs, statusThreadTs } = resolveSlackThreadTargets({
+      replyToMode: "off",
+      message: {
+        type: "message",
+        channel: "C1",
+        ts: "123",
+        thread_ts: "456",
+      },
+    });
+
+    expect(replyThreadTs).toBe("456");
+    expect(statusThreadTs).toBe("456");
+  });
+
+  it("threads top-level replies when mode is all", () => {
+    const { replyThreadTs, statusThreadTs } = resolveSlackThreadTargets({
+      replyToMode: "all",
+      message: {
+        type: "message",
+        channel: "C1",
+        ts: "123",
+      },
+    });
+
+    expect(replyThreadTs).toBe("123");
+    expect(statusThreadTs).toBe("123");
+  });
+
+  it("keeps status threading even when reply threading is off", () => {
+    const { replyThreadTs, statusThreadTs } = resolveSlackThreadTargets({
+      replyToMode: "off",
+      message: {
+        type: "message",
+        channel: "C1",
+        ts: "123",
+      },
+    });
+
+    expect(replyThreadTs).toBeUndefined();
+    expect(statusThreadTs).toBe("123");
+  });
+});

src/slack/threading.ts

@@ -0,0 +1,15 @@
+import type { ReplyToMode } from "../config/types.js";
+import type { SlackAppMentionEvent, SlackMessageEvent } from "./types.js";
+
+export function resolveSlackThreadTargets(params: {
+  message: SlackMessageEvent | SlackAppMentionEvent;
+  replyToMode: ReplyToMode;
+}) {
+  const incomingThreadTs = params.message.thread_ts;
+  const eventTs = params.message.event_ts;
+  const messageTs = params.message.ts ?? eventTs;
+  const replyThreadTs =
+    incomingThreadTs ?? (params.replyToMode === "all" ? messageTs : undefined);
+  const statusThreadTs = replyThreadTs ?? messageTs;
+  return { replyThreadTs, statusThreadTs };
+}

src/slack/types.ts

@@ -0,0 +1,38 @@
+export type SlackFile = {
+  id?: string;
+  name?: string;
+  mimetype?: string;
+  size?: number;
+  url_private?: string;
+  url_private_download?: string;
+};
+
+export type SlackMessageEvent = {
+  type: "message";
+  user?: string;
+  bot_id?: string;
+  subtype?: string;
+  username?: string;
+  text?: string;
+  ts?: string;
+  thread_ts?: string;
+  event_ts?: string;
+  parent_user_id?: string;
+  channel: string;
+  channel_type?: "im" | "mpim" | "channel" | "group";
+  files?: SlackFile[];
+};
+
+export type SlackAppMentionEvent = {
+  type: "app_mention";
+  user?: string;
+  bot_id?: string;
+  username?: string;
+  text?: string;
+  ts?: string;
+  thread_ts?: string;
+  event_ts?: string;
+  parent_user_id?: string;
+  channel: string;
+  channel_type?: "im" | "mpim" | "channel" | "group";
+};