Basic structure of the project

- Added a model with in-memory database, and routes, controller and
middleware to enable making initial CRUD calls to endpoints;

- Added jest and an initial test.

jest.config.ts

@@ -0,0 +1,11 @@
+module.exports = {
+  preset: 'ts-jest',
+  testEnvironment: 'node',
+  moduleFileExtensions: ['ts', 'js'],
+  testMatch: ['**/tests/**/*.test.(ts|js)'],
+  globals: {
+    'ts-jest': {
+      tsconfig: 'tsconfig.json',
+    },
+  },
+};

package.json

@@ -5,8 +5,9 @@
   "main": "dist/app.js",
   "scripts": {
     "start": "tsc && node dist/app.js",
+    "dev": "nodemon --watch 'src/**/*.ts' --exec 'ts-node' src/app.ts",
     "lint": "eslint . --ext .ts",
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "test": "jest --watch"
   },
   "repository": {
     "type": "git",
@@ -23,8 +24,12 @@
   "devDependencies": {
     "@eslint/js": "^9.23.0",
     "@types/express": "^5.0.1",
+    "@types/jest": "^29.5.14",
     "eslint": "^9.23.0",
     "globals": "^16.0.0",
+    "jest": "^29.7.0",
+    "ts-jest": "^29.3.1",
+    "ts-node": "^10.9.2",
     "typescript": "^5.8.2",
     "typescript-eslint": "^8.29.0"
   },

src/app.ts

@@ -1,11 +1,22 @@
 import express from 'express'
+import topicRoutes from './routes/topicRoutes'
+import { errorHandler } from './middleware/errorHandler'
+
 const app = express()
 const port = 3000
 
+app.use(express.json())
+
+// Routes
 app.get('/', (req, res) => {
   res.send('Hello World!')
 })
 
+app.use('/api/topics', topicRoutes);
+
+// Global error handler (should be after routes)
+app.use(errorHandler);
+
 app.listen(port, () => {
   return console.log(`Express is listening at http://localhost:${port}`)
 })

src/controllers/topicController.ts

@@ -0,0 +1,79 @@
+import { Request, Response, NextFunction } from 'express';
+import { topics, Topic } from '../models/topic';
+
+// Create a topic
+export const createTopic = (req: Request, res: Response, next: NextFunction) => {
+  try {
+    const { name, content } = req.body;
+    const newTopic: Topic = {
+      id: Date.now(),
+      name,
+      content,
+      createdAt: new Date().toString(),
+      updatedAt: new Date().toString(),
+      version: 1,
+      parentTopicId: 1
+    };
+    topics.push(newTopic);
+    res.status(201).json(newTopic);
+  } catch (error) {
+    next(error);
+  }
+};
+
+// Read all topics
+export const getTopics = (req: Request, res: Response, next: NextFunction) => {
+  try {
+    res.json(topics);
+  } catch (error) {
+    next(error);
+  }
+};
+
+// Read single topic
+export const getTopicById = (req: Request, res: Response, next: NextFunction) => {
+  try {
+    const id = parseInt(req.params.id, 10);
+    const topic = topics.find((i) => i.id === id);
+    if (!topic) {
+      res.status(404).json({ message: 'Topic not found' });
+      return;
+    }
+    res.json(topic);
+  } catch (error) {
+    next(error);
+  }
+};
+
+// Update a topic
+export const updateTopic = (req: Request, res: Response, next: NextFunction) => {
+  try {
+    const id = parseInt(req.params.id, 10);
+    const { name } = req.body;
+    const topicIndex = topics.findIndex((i) => i.id === id);
+    if (topicIndex === -1) {
+      res.status(404).json({ message: 'Topic not found' });
+      return;
+    }
+    topics[topicIndex].name = name;
+    res.json(topics[topicIndex]);
+  } catch (error) {
+    next(error);
+  }
+};
+
+// Delete a topic
+export const deleteTopic = (req: Request, res: Response, next: NextFunction) => {
+  try {
+    const id = parseInt(req.params.id, 10);
+    const topicIndex = topics.findIndex((i) => i.id === id);
+    if (topicIndex === -1) {
+      res.status(404).json({ message: 'Topic not found' });
+      return;
+    }
+    const deletedTopic = topics.splice(topicIndex, 1)[0];
+    res.json(deletedTopic);
+  } catch (error) {
+    next(error);
+  }
+};

src/middleware/errorHandler.ts

@@ -0,0 +1,17 @@
+import { Request, Response, NextFunction } from 'express';
+
+export interface AppError extends Error {
+  status?: number;
+}
+
+export const errorHandler = (
+  err: AppError,
+  req: Request,
+  res: Response,
+  next: NextFunction
+) => {
+  console.error(err);
+  res.status(err.status || 500).json({
+    message: err.message || 'Internal Server Error',
+  });
+};

src/models/resource.ts

@@ -0,0 +1,11 @@
+export interface Resource {
+  id: number;
+  topicId: string;
+  url: string;
+  description: string;
+  type: string;
+  createdAt: string;
+  updatedAt: string;
+}
+
+export let resources: Resource[] = [];

src/models/topic.ts

@@ -0,0 +1,11 @@
+export interface Topic {
+  id: number;
+  name: string;
+  content: string;
+  createdAt: string;
+  updatedAt: string;
+  version: number;
+  parentTopicId: number;
+}
+
+export let topics: Topic[] = [];

src/models/user.ts

@@ -0,0 +1,9 @@
+export interface User {
+  id: number;
+  name: string;
+  email: string;
+  role: string;
+  createdAt: string;
+}
+
+export let users: User[] = []

src/routes/topicRoutes.ts

@@ -0,0 +1,18 @@
+import { Router } from 'express';
+import {
+  createTopic,
+  getTopics,
+  getTopicById,
+  updateTopic,
+  deleteTopic,
+} from '../controllers/topicController';
+
+const router = Router();
+
+router.get('/', getTopics);
+router.get('/:id', getTopicById);
+router.post('/', createTopic);
+router.put('/:id', updateTopic);
+router.delete('/:id', deleteTopic);
+
+export default router;

tests/topicController.test.ts

@@ -0,0 +1,22 @@
+import { Request, Response } from 'express';
+import { getTopics } from '../src/controllers/topicController';
+import { topics } from '../src/models/topic';
+
+describe('Topic Controller', () => {
+  it('should return an empty array when no topics exist', () => {
+    // Create mock objects for Request, Response, and NextFunction
+    const req = {} as Request;
+    const res = {
+      json: jest.fn(),
+    } as unknown as Response;
+
+    // Ensure that our in-memory store is empty
+    topics.length = 0;
+
+    // Execute our controller function
+    getTopics(req, res, jest.fn());
+
+    // Expect that res.json was called with an empty array
+    expect(res.json).toHaveBeenCalledWith([]);
+  });
+});