fix: file_share等のユーザー投稿subtypeを転送対象にする

src/lib/__tests__/messageFilter.test.ts

@@ -30,7 +30,7 @@ describe('isForwardableMessage', () => {
 		assert.equal(isForwardableMessage(message, timesAllChannelId), false);
 	});
 
-	it('subtypeを持つメッセージはfalseを返す (channel_join)', () => {
+	it('転送対象外のsubtypeはfalseを返す (channel_join)', () => {
 		const message = {
 			type: 'message',
 			subtype: 'channel_join',
@@ -41,7 +41,7 @@ describe('isForwardableMessage', () => {
 		assert.equal(isForwardableMessage(message, timesAllChannelId), false);
 	});
 
-	it('subtypeを持つメッセージはfalseを返す (bot_message)', () => {
+	it('転送対象外のsubtypeはfalseを返す (bot_message)', () => {
 		const message = {
 			type: 'message',
 			subtype: 'bot_message',
@@ -52,7 +52,7 @@ describe('isForwardableMessage', () => {
 		assert.equal(isForwardableMessage(message, timesAllChannelId), false);
 	});
 
-	it('subtypeを持つメッセージはfalseを返す (message_changed)', () => {
+	it('転送対象外のsubtypeはfalseを返す (message_changed)', () => {
 		const message = {
 			type: 'message',
 			subtype: 'message_changed',
@@ -63,4 +63,48 @@ describe('isForwardableMessage', () => {
 		} as AllMessageEvents;
 		assert.equal(isForwardableMessage(message, timesAllChannelId), false);
 	});
+
+	it('file_shareは転送対象としてtrueを返す', () => {
+		const message = {
+			type: 'message',
+			subtype: 'file_share',
+			channel: 'C_OTHER',
+			channel_type: 'channel',
+			ts: '1234567890.123456',
+		} as AllMessageEvents;
+		assert.equal(isForwardableMessage(message, timesAllChannelId), true);
+	});
+
+	it('me_messageは転送対象としてtrueを返す', () => {
+		const message = {
+			type: 'message',
+			subtype: 'me_message',
+			channel: 'C_OTHER',
+			channel_type: 'channel',
+			ts: '1234567890.123456',
+		} as AllMessageEvents;
+		assert.equal(isForwardableMessage(message, timesAllChannelId), true);
+	});
+
+	it('thread_broadcastは転送対象としてtrueを返す', () => {
+		const message = {
+			type: 'message',
+			subtype: 'thread_broadcast',
+			channel: 'C_OTHER',
+			channel_type: 'channel',
+			ts: '1234567890.123456',
+		} as AllMessageEvents;
+		assert.equal(isForwardableMessage(message, timesAllChannelId), true);
+	});
+
+	it('未知のsubtypeは転送対象外としてfalseを返す', () => {
+		const message = {
+			type: 'message',
+			subtype: 'some_unknown_subtype',
+			channel: 'C_OTHER',
+			channel_type: 'channel',
+			ts: '1234567890.123456',
+		} as unknown as AllMessageEvents;
+		assert.equal(isForwardableMessage(message, timesAllChannelId), false);
+	});
 });

src/lib/messageFilter.ts

@@ -1,15 +1,25 @@
 import type { AllMessageEvents } from '@slack/types';
 
+/**
+ * 転送対象のsubtype。
+ * undefinedも転送対象（通常のメッセージ）。
+ * https://api.slack.com/events/message#subtypes
+ */
+const forwardableSubtypes = new Set<string | undefined>([
+	undefined,
+	'file_share',
+	'me_message',
+	'thread_broadcast',
+]);
+
 /**
  * 転送対象のメッセージかどうかを判定する。
- * subtypeを持つメッセージ(channel_join, message_changed, bot_message等)は
- * すべて転送対象外とする。hidden判定も不要(hidden: trueを持つのはsubtype付きのみ)。
  */
 export function isForwardableMessage(
 	message: AllMessageEvents,
 	timesAllChannelId: string,
 ): boolean {
-	if (message.subtype !== undefined) return false;
+	if (!forwardableSubtypes.has(message.subtype)) return false;
 	if (message.channel_type !== 'channel') return false;
 	if (message.channel === timesAllChannelId) return false;
 	return true;