feat: smarter partial update debounce (#42)

Author: mdjastrzebski

.changeset/wet-hotels-end.md

@@ -0,0 +1,6 @@
+---
+'@callstack/byorg-utils': minor
+'@callstack/byorg-slack': patch
+---
+
+utils: debouncePartialUpdate function for smart debounce handling

packages/slack/package.json

@@ -34,7 +34,6 @@
     "@callstack/slack-rich-text": "workspace:*",
     "@slack/bolt": "^4.1.1",
     "@slack/web-api": "^7.8.0",
-    "p-debounce": "^4.0.0",
     "ts-regex-builder": "^1.8.2"
   },
   "devDependencies": {

packages/slack/src/app.ts

@@ -1,22 +1,21 @@
 import Slack, { LogLevel, SayFn } from '@slack/bolt';
 import { ContextBlock, RichTextBlock, WebClient } from '@slack/web-api';
 import { Application } from '@callstack/byorg-core';
-import { logger } from '@callstack/byorg-utils';
+import { debouncePartialUpdate, logger } from '@callstack/byorg-utils';
 import { parseMarkdownToRichTextBlock } from '@callstack/slack-rich-text';
-import pDebounce from 'p-debounce';
 import {
   SlackMessage,
   SlackApplicationConfig as SlackApplicationConfig,
   ConversationMode,
 } from './types.js';
 import { fetchFileInfo, getThread } from './slack-api.js';
 import { formatGroupMessage, toCoreMessage } from './messages.js';
-import { wait } from './utils.js';
 import { getBotId } from './bot-id.js';
 
 type MessageBlock = RichTextBlock | ContextBlock;
 
-const UPDATE_THROTTLE_TIME = 1000;
+const MIN_UPDATE_TIME = 3000;
+const MIN_RESPONSE_LENGTH = 250;
 const NOTIFICATION_TEXT_LIMIT = 200;
 
 const RESPONDING_BLOCK: MessageBlock = {
@@ -91,8 +90,6 @@ function configureSlackApp(app: Application, slack: Slack.App): void {
           blocks,
         });
         responseMessageTs = responseMessage.ts as string;
-
-        await wait(UPDATE_THROTTLE_TIME);
         return;
       }
 
@@ -104,15 +101,17 @@ function configureSlackApp(app: Application, slack: Slack.App): void {
         parse: 'none',
       });
 
-      await wait(UPDATE_THROTTLE_TIME);
       return;
     };
 
     let updatePartialResponsePromise: Promise<void> = Promise.resolve();
-    const updateResponseMessageWithThrottle = pDebounce.promise(updateResponseMessage);
+    const updateResponseMessageWithDebounce = debouncePartialUpdate(updateResponseMessage, {
+      minUpdateTime: MIN_UPDATE_TIME,
+      minResponseLength: MIN_RESPONSE_LENGTH,
+    });
 
     const handlePartialResponse = (response: string): void => {
-      updatePartialResponsePromise = updateResponseMessageWithThrottle(response);
+      updatePartialResponsePromise = updateResponseMessageWithDebounce(response);
     };
 
     const startTime = performance.now();

packages/slack/src/utils.ts

@@ -0,0 +1,38 @@
+export type PartialUpdateFn = (text: string) => Promise<void>;
+export type DebouncePartialUpdateOptions = {
+  minUpdateTime: number;
+  minResponseLength: number;
+};
+
+export function debouncePartialUpdate(
+  partialUpdate: PartialUpdateFn,
+  { minResponseLength, minUpdateTime }: DebouncePartialUpdateOptions,
+) {
+  let pendingPromise: Promise<void> | undefined;
+  let lastUpdate: number | undefined;
+
+  return async function (text: string) {
+    // Wait for the last update to finish
+    if (pendingPromise) {
+      return pendingPromise;
+    }
+
+    // Time-based debounce
+    if (lastUpdate !== undefined && performance.now() - lastUpdate < minUpdateTime) {
+      return;
+    }
+
+    // Skip too short initial messages
+    if (text.length < minResponseLength) {
+      return;
+    }
+
+    try {
+      lastUpdate = performance.now();
+      pendingPromise = partialUpdate(text);
+      return await pendingPromise;
+    } finally {
+      pendingPromise = undefined;
+    }
+  };
+}

packages/utils/src/debounce.ts

@@ -5,3 +5,6 @@ export type { Logger, LogLevel } from './logger/types.js';
 export { requireEnv } from './env.js';
 
 export { withCache } from './with-cache.js';
+
+export { debouncePartialUpdate } from './debounce.js';
+export type { PartialUpdateFn, DebouncePartialUpdateOptions } from './debounce.js';