Simple Todo REST API using Express.js

backend/controllers/todoController.js

@@ -0,0 +1,49 @@
+const Todo = require("../models/todoModel");
+
+exports.getTodos = (req, res) => {
+  res.json(Todo.getAll());
+};
+
+exports.getTodoById = (req, res) => {
+  const { id } = req.params;
+  const todo = Todo.getById(id);
+
+  if (!todo) {
+    return res.status(404).json({ message: "Todo not found" });
+  }
+
+  res.json(todo);
+};
+
+exports.createTodo = (req, res) => {
+  const { title } = req.body;
+
+  if (!title) {
+    return res.status(400).json({ message: "Title is required" });
+  }
+
+  const newTodo = Todo.create(req.body);
+  res.status(201).json(newTodo);
+};
+
+exports.updateTodo = (req, res) => {
+  const { id } = req.params;
+  const updated = Todo.update(id, req.body);
+
+  if (!updated) {
+    return res.status(404).json({ message: "Todo not found" });
+  }
+
+  res.json(updated);
+};
+
+exports.deleteTodo = (req, res) => {
+  const { id } = req.params;
+  const deleted = Todo.remove(id);
+
+  if (!deleted) {
+    return res.status(404).json({ message: "Todo not found" });
+  }
+
+  res.json(deleted);
+};

backend/index.js

@@ -1,11 +1,11 @@
 const express = require("express");
 const app = express();
 const PORT = process.env.PORT || 4000;
+const todoRoutes = require('./routes/todoRoutes');
 
-// Basic route
-app.get("/", (req, res) => {
-  res.send("Hello from Express!");
-});
+app.use(express.json());
+
+app.use('/api/todos', todoRoutes);
 
 // Start server
 app.listen(PORT, () => {

backend/models/todoModel.js

@@ -0,0 +1,63 @@
+let todos = [
+  {
+    id: 1,
+    title: "Todo Number One",
+    completed: false,
+    createdAt: new Date("2026-02-15"),
+  },
+  {
+    id: 2,
+    title: "Number Two Todo",
+    completed: true,
+    createdAt: new Date("2026-02-16"),
+  },
+  {
+    id: 3,
+    title: "Third Todo",
+    completed: false,
+    createdAt: new Date("2026-02-17"),
+  },
+];
+
+let currentId = 1;
+
+const getAll = () => todos;
+
+const getById = (id) => todos.find((t) => t.id === id);
+
+const create = (data) => {
+  const newTodo = {
+    id: currentId++,
+    title: data.title,
+    completed: data.completed ?? false,
+    createdAt: new Date(),
+  };
+
+  todos.push(newTodo);
+  return newTodo;
+};
+
+const update = (id, data) => {
+  const todo = getById(id);
+  if (!todo) return null;
+
+  if (data.title !== undefined) todo.title = data.title;
+  if (data.completed !== undefined) todo.completed = data.completed;
+
+  return todo;
+};
+
+const remove = (id) => {
+  const index = todos.findIndex((t) => t.id === id);
+  if (index === -1) return null;
+
+  return todos.splice(index, 1)[0];
+};
+
+module.exports = {
+  getAll,
+  getById,
+  create,
+  update,
+  remove,
+};

backend/package.json

@@ -5,6 +5,11 @@
     "start": "node index.js"
   },
   "dependencies": {
-    "express": "^4.18.2"
-  }
+    "express": "^4.22.1"
+  },
+  "main": "index.js",
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "description": ""
 }

backend/routes/todoRoutes.js

@@ -0,0 +1,11 @@
+const express = require("express");
+const router = express.Router();
+const todoController = require("../controllers/todoController");
+
+router.get("/", todoController.getTodos);
+router.get("/:id", todoController.getTodoById);
+router.post("/", todoController.createTodo);
+router.put("/:id", todoController.updateTodo);
+router.delete("/:id", todoController.deleteTodo);
+
+module.exports = router;