fix(api): allow deleting messages without send permission (#2918)

fluxer_api/src/api/channel/services/message/MessageValidationService.ts

@@ -252,9 +252,7 @@ export class MessageValidationService {
 		const isAuthor = message.authorId === userId;
 		if (!guild) return isAuthor;
 		if (isAuthor) return true;
-		const canManageMessages =
-			(await hasPermission(Permissions.SEND_MESSAGES)) && (await hasPermission(Permissions.MANAGE_MESSAGES));
-		return canManageMessages;
+		return hasPermission(Permissions.MANAGE_MESSAGES);
 	}
 
 	private validateVoiceMessageConstraints(

fluxer_api/src/api/channel/tests/MessageDeletePermissions.test.ts

@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import type {TestAccount} from '@app/api/auth/tests/AuthTestUtils';
+import {
+	createPermissionOverwrite,
+	sendChannelMessage,
+	setupTestGuildWithMembers,
+} from '@app/api/channel/tests/ChannelTestUtils';
+import {type ApiTestHarness, createApiTestHarness} from '@app/api/test/ApiTestHarness';
+import {HTTP_STATUS} from '@app/api/test/TestConstants';
+import {createBuilder} from '@app/api/test/TestRequestBuilder';
+import {Permissions} from '@fluxer/constants/src/ChannelConstants';
+import {afterAll, beforeAll, beforeEach, describe, it} from 'vitest';
+
+describe('Message delete permissions', () => {
+	let harness: ApiTestHarness;
+
+	beforeAll(async () => {
+		harness = await createApiTestHarness();
+	});
+
+	beforeEach(async () => {
+		await harness.reset();
+	});
+
+	afterAll(async () => {
+		await harness?.shutdown();
+	});
+
+	it('lets a member with MANAGE_MESSAGES but without SEND_MESSAGES delete another member message', async () => {
+		const {owner, members, systemChannel} = await setupTestGuildWithMembers(harness, 2);
+		const [author, moderator] = members as [TestAccount, TestAccount];
+		const message = await sendChannelMessage(harness, author.token, systemChannel.id, 'delete me');
+		await createPermissionOverwrite(harness, owner.token, systemChannel.id, moderator.userId, {
+			type: 1,
+			allow: Permissions.MANAGE_MESSAGES.toString(),
+			deny: Permissions.SEND_MESSAGES.toString(),
+		});
+
+		await createBuilder(harness, moderator.token)
+			.delete(`/channels/${systemChannel.id}/messages/${message.id}`)
+			.expect(HTTP_STATUS.NO_CONTENT)
+			.execute();
+
+		await createBuilder(harness, author.token)
+			.get(`/channels/${systemChannel.id}/messages/${message.id}`)
+			.expect(HTTP_STATUS.NOT_FOUND)
+			.execute();
+	});
+
+	it('refuses a member without MANAGE_MESSAGES deleting another member message', async () => {
+		const {members, systemChannel} = await setupTestGuildWithMembers(harness, 2);
+		const [author, other] = members as [TestAccount, TestAccount];
+		const message = await sendChannelMessage(harness, author.token, systemChannel.id, 'keep me');
+
+		await createBuilder(harness, other.token)
+			.delete(`/channels/${systemChannel.id}/messages/${message.id}`)
+			.expect(HTTP_STATUS.FORBIDDEN, 'MISSING_PERMISSIONS')
+			.execute();
+	});
+});