memegoat/backend/src/messages/messages.service.spec.ts

import { ForbiddenException } from "@nestjs/common";
import { Test, TestingModule } from "@nestjs/testing";
import { EventsGateway } from "../realtime/events.gateway";
import { MessagesService } from "./messages.service";
import { MessagesRepository } from "./repositories/messages.repository";

describe("MessagesService", () => {
	let service: MessagesService;
	let _repository: MessagesRepository;
	let _eventsGateway: EventsGateway;

	const mockMessagesRepository = {
		findConversationBetweenUsers: jest.fn(),
		createConversation: jest.fn(),
		addParticipant: jest.fn(),
		createMessage: jest.fn(),
		findAllConversations: jest.fn(),
		isParticipant: jest.fn(),
		findMessagesByConversationId: jest.fn(),
		markAsRead: jest.fn(),
		countUnreadMessages: jest.fn(),
	};

	const mockEventsGateway = {
		sendToUser: jest.fn(),
	};

	beforeEach(async () => {
		const module: TestingModule = await Test.createTestingModule({
			providers: [
				MessagesService,
				{ provide: MessagesRepository, useValue: mockMessagesRepository },
				{ provide: EventsGateway, useValue: mockEventsGateway },
			],
		}).compile();

		service = module.get<MessagesService>(MessagesService);
		_repository = module.get<MessagesRepository>(MessagesRepository);
		_eventsGateway = module.get<EventsGateway>(EventsGateway);
	});

	describe("sendMessage", () => {
		it("should send message to existing conversation", async () => {
			const senderId = "s1";
			const dto = { recipientId: "r1", text: "hello" };
			mockMessagesRepository.findConversationBetweenUsers.mockResolvedValue({
				id: "conv1",
			});
			mockMessagesRepository.createMessage.mockResolvedValue({
				id: "m1",
				text: "hello",
			});

			const result = await service.sendMessage(senderId, dto);

			expect(result.id).toBe("m1");
			expect(mockEventsGateway.sendToUser).toHaveBeenCalledWith(
				"r1",
				"new_message",
				expect.anything(),
			);
		});

		it("should create new conversation if not exists", async () => {
			const senderId = "s1";
			const dto = { recipientId: "r1", text: "hello" };
			mockMessagesRepository.findConversationBetweenUsers.mockResolvedValue(null);
			mockMessagesRepository.createConversation.mockResolvedValue({
				id: "new_conv",
			});
			mockMessagesRepository.createMessage.mockResolvedValue({ id: "m1" });

			await service.sendMessage(senderId, dto);

			expect(mockMessagesRepository.createConversation).toHaveBeenCalled();
			expect(mockMessagesRepository.addParticipant).toHaveBeenCalledTimes(2);
		});
	});

	describe("getMessages", () => {
		it("should return messages if user is participant", async () => {
			mockMessagesRepository.isParticipant.mockResolvedValue(true);
			mockMessagesRepository.findMessagesByConversationId.mockResolvedValue([
				{ id: "m1" },
			]);

			const result = await service.getMessages("u1", "conv1");
			expect(result).toHaveLength(1);
		});

		it("should throw ForbiddenException if user is not participant", async () => {
			mockMessagesRepository.isParticipant.mockResolvedValue(false);
			await expect(service.getMessages("u1", "conv1")).rejects.toThrow(
				ForbiddenException,
			);
		});
	});
});