refactor with JoinToConversation middleware

packages/slack/src/utils/slash-command-parser.ts

@@ -2,6 +2,10 @@ import { GrowiCommand } from '../interfaces/growi-command';
 import { InvalidGrowiCommandError } from '../models/errors';
 
 export const parseSlashCommand = (slashCommand:{[key:string]:string}): GrowiCommand => {
+  if (slashCommand.text == null) {
+    throw new InvalidGrowiCommandError('The SlashCommand.text is null');
+  }
+
   const trimmedText = slashCommand.text.trim();
   const splitted = trimmedText.split(' ');
 

packages/slackbot-proxy/src/controllers/slack.ts

@@ -25,6 +25,7 @@ import { RelationsService } from '~/services/RelationsService';
 import { UnregisterService } from '~/services/UnregisterService';
 import { InvalidUrlError } from '../models/errors';
 import loggerFactory from '~/utils/logger';
+import { JoinToConversationMiddleware } from '~/middlewares/slack-to-growi/join-to-conversation';
 
 
 const logger = loggerFactory('slackbot-proxy:controllers:slack');
@@ -97,21 +98,10 @@ export class SlackCtrl {
   }
 
   @Post('/commands')
-  @UseBefore(AddSigningSecretToReq, verifySlackRequest, AuthorizeCommandMiddleware)
+  @UseBefore(AddSigningSecretToReq, verifySlackRequest, AuthorizeCommandMiddleware, JoinToConversationMiddleware)
   async handleCommand(@Req() req: SlackOauthReq, @Res() res: Res): Promise<void|string|Res|WebAPICallResult> {
     const { body, authorizeResult } = req;
 
-    if (body.text == null) {
-      return 'No text.';
-    }
-
-    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
-    const client = generateWebClient(authorizeResult.botToken!);
-    const joinResult = await client.conversations.join({ channel: body.channel_id });
-    if (!joinResult.ok) {
-      logger.error(joinResult.error, joinResult);
-    }
-
     const growiCommand = parseSlashCommand(body);
 
     // register

packages/slackbot-proxy/src/middlewares/slack-to-growi/join-to-conversation.ts

@@ -0,0 +1,32 @@
+import { generateWebClient } from '@growi/slack';
+import {
+  IMiddleware, Middleware, Req,
+} from '@tsed/common';
+
+import Logger from 'bunyan';
+import { SlackOauthReq } from '~/interfaces/slack-to-growi/slack-oauth-req';
+
+import loggerFactory from '~/utils/logger';
+
+const logger: Logger = loggerFactory('slackbot-proxy:middlewares:JoinToConversationsMiddleware');
+
+
+/**
+ * This middleware should be processed after AuthorizeCommandMiddleware or AuthorizeInteractionMiddleware
+ */
+@Middleware()
+export class JoinToConversationMiddleware implements IMiddleware {
+
+  async use(@Req() req: SlackOauthReq): Promise<void> {
+    const { body, authorizeResult } = req;
+
+    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+    const client = generateWebClient(authorizeResult.botToken!);
+
+    const joinResult = await client.conversations.join({ channel: body.channel_id });
+    if (!joinResult.ok) {
+      logger.error(joinResult.error, joinResult);
+    }
+  }
+
+}