Added unit and integration tests

task-api/src/routes/tasks.js

@@ -1,24 +1,41 @@
-const express = require('express');
+const express = require("express");
 const router = express.Router();
-const taskService = require('../services/taskService');
-const { validateCreateTask, validateUpdateTask } = require('../utils/validators');
+const taskService = require("../services/taskService");
+const {
+  validateCreateTask,
+  validateUpdateTask,
+  validateAssignee,
+} = require("../utils/validators");
 
-router.get('/stats', (req, res) => {
+const VALID_STATUS = ["todo", "in_progress", "done"];
+
+router.get("/stats", (req, res) => {
   const stats = taskService.getStats();
   res.json(stats);
 });
 
-router.get('/', (req, res) => {
+router.get("/", (req, res) => {
   const { status, page, limit } = req.query;
 
   if (status) {
+    if (!VALID_STATUS.includes(status)) {
+      return res.status(400).json({ error: "invalid status query parameter" });
+    }
     const tasks = taskService.getByStatus(status);
     return res.json(tasks);
   }
 
   if (page !== undefined || limit !== undefined) {
-    const pageNum = parseInt(page) || 1;
-    const limitNum = parseInt(limit) || 10;
+    const pageNum = page !== undefined ? parseInt(page, 10) : 1;
+    const limitNum = limit !== undefined ? parseInt(limit, 10) : 10;
+    if (
+      (page !== undefined && (Number.isNaN(pageNum) || pageNum < 1)) ||
+      (limit !== undefined && (Number.isNaN(limitNum) || limitNum < 1))
+    ) {
+      return res
+        .status(400)
+        .json({ error: "page and limit must be positive integers" });
+    }
     const tasks = taskService.getPaginated(pageNum, limitNum);
     return res.json(tasks);
   }
@@ -27,7 +44,7 @@ router.get('/', (req, res) => {
   res.json(tasks);
 });
 
-router.post('/', (req, res) => {
+router.post("/", (req, res) => {
   const error = validateCreateTask(req.body);
   if (error) {
     return res.status(400).json({ error });
@@ -37,35 +54,51 @@ router.post('/', (req, res) => {
   res.status(201).json(task);
 });
 
-router.put('/:id', (req, res) => {
+router.put("/:id", (req, res) => {
   const error = validateUpdateTask(req.body);
   if (error) {
     return res.status(400).json({ error });
   }
 
   const task = taskService.update(req.params.id, req.body);
   if (!task) {
-    return res.status(404).json({ error: 'Task not found' });
+    return res.status(404).json({ error: "Task not found" });
   }
 
   res.json(task);
 });
 
-router.delete('/:id', (req, res) => {
+router.delete("/:id", (req, res) => {
   const deleted = taskService.remove(req.params.id);
   if (!deleted) {
-    return res.status(404).json({ error: 'Task not found' });
+    return res.status(404).json({ error: "Task not found" });
   }
 
   res.status(204).send();
 });
 
-router.patch('/:id/complete', (req, res) => {
+router.patch("/:id/complete", (req, res) => {
   const task = taskService.completeTask(req.params.id);
   if (!task) {
-    return res.status(404).json({ error: 'Task not found' });
+    return res.status(404).json({ error: "Task not found" });
+  }
+
+  res.json(task);
+});
+
+router.patch("/:id/assign", (req, res) => {
+  const error = validateAssignee(req.body);
+  if (error) {
+    return res.status(400).json({ error });
+  }
+
+  const assignee = req.body.assignee.trim();
+  const task = taskService.assignTask(req.params.id, assignee);
+  if (!task) {
+    return res.status(404).json({ error: "Task not found" });
   }
 
+  // Overwrite existing assignee when present because reassignment should update the task assignee.
   res.json(task);
 });
 

task-api/src/services/taskService.js

@@ -1,15 +1,17 @@
-const { v4: uuidv4 } = require('uuid');
+const { v4: uuidv4 } = require("uuid");
 
 let tasks = [];
 
 const getAll = () => [...tasks];
 
 const findById = (id) => tasks.find((t) => t.id === id);
 
-const getByStatus = (status) => tasks.filter((t) => t.status.includes(status));
+const getByStatus = (status) => tasks.filter((t) => t.status === status);
 
 const getPaginated = (page, limit) => {
-  const offset = page * limit;
+  // Expected: page 1 begins at offset 0, page 2 begins at offset limit.
+  // Actual bug: offset was computed as page * limit, causing the first page to skip items.
+  const offset = (page - 1) * limit;
   return tasks.slice(offset, offset + limit);
 };
 
@@ -20,22 +22,30 @@ const getStats = () => {
 
   tasks.forEach((t) => {
     if (counts[t.status] !== undefined) counts[t.status]++;
-    if (t.dueDate && t.status !== 'done' && new Date(t.dueDate) < now) {
+    if (t.dueDate && t.status !== "done" && new Date(t.dueDate) < now) {
       overdue++;
     }
   });
 
   return { ...counts, overdue };
 };
 
-const create = ({ title, description = '', status = 'todo', priority = 'medium', dueDate = null }) => {
+const create = ({
+  title,
+  description = "",
+  status = "todo",
+  priority = "medium",
+  dueDate = null,
+  assignee = null,
+}) => {
   const task = {
     id: uuidv4(),
     title,
     description,
     status,
     priority,
     dueDate,
+    assignee,
     completedAt: null,
     createdAt: new Date().toISOString(),
   };
@@ -52,6 +62,19 @@ const update = (id, fields) => {
   return updated;
 };
 
+const assignTask = (id, assignee) => {
+  const task = findById(id);
+  if (!task) return null;
+
+  const updated = {
+    ...task,
+    assignee,
+  };
+  const index = tasks.findIndex((t) => t.id === id);
+  tasks[index] = updated;
+  return updated;
+};
+
 const remove = (id) => {
   const index = tasks.findIndex((t) => t.id === id);
   if (index === -1) return false;
@@ -66,8 +89,8 @@ const completeTask = (id) => {
 
   const updated = {
     ...task,
-    priority: 'medium',
-    status: 'done',
+    priority: "medium",
+    status: "done",
     completedAt: new Date().toISOString(),
   };
 
@@ -90,5 +113,6 @@ module.exports = {
   update,
   remove,
   completeTask,
+  assignTask,
   _reset,
 };

task-api/src/utils/validators.js

@@ -1,36 +1,66 @@
-const VALID_STATUSES = ['todo', 'in_progress', 'done'];
-const VALID_PRIORITIES = ['low', 'medium', 'high'];
+const VALID_STATUSES = ["todo", "in_progress", "done"];
+const VALID_PRIORITIES = ["low", "medium", "high"];
 
 const validateCreateTask = (body) => {
-  if (!body.title || typeof body.title !== 'string' || body.title.trim() === '') {
-    return 'title is required and must be a non-empty string';
+  if (
+    !body.title ||
+    typeof body.title !== "string" ||
+    body.title.trim() === ""
+  ) {
+    return "title is required and must be a non-empty string";
   }
   if (body.status && !VALID_STATUSES.includes(body.status)) {
-    return `status must be one of: ${VALID_STATUSES.join(', ')}`;
+    return `status must be one of: ${VALID_STATUSES.join(", ")}`;
   }
   if (body.priority && !VALID_PRIORITIES.includes(body.priority)) {
-    return `priority must be one of: ${VALID_PRIORITIES.join(', ')}`;
+    return `priority must be one of: ${VALID_PRIORITIES.join(", ")}`;
+  }
+  if (
+    body.assignee !== undefined &&
+    (typeof body.assignee !== "string" || body.assignee.trim() === "")
+  ) {
+    return "assignee must be a non-empty string when provided";
   }
   if (body.dueDate && isNaN(Date.parse(body.dueDate))) {
-    return 'dueDate must be a valid ISO date string';
+    return "dueDate must be a valid ISO date string";
   }
   return null;
 };
 
 const validateUpdateTask = (body) => {
-  if (body.title !== undefined && (typeof body.title !== 'string' || body.title.trim() === '')) {
-    return 'title must be a non-empty string';
+  if (
+    body.title !== undefined &&
+    (typeof body.title !== "string" || body.title.trim() === "")
+  ) {
+    return "title must be a non-empty string";
   }
   if (body.status && !VALID_STATUSES.includes(body.status)) {
-    return `status must be one of: ${VALID_STATUSES.join(', ')}`;
+    return `status must be one of: ${VALID_STATUSES.join(", ")}`;
   }
   if (body.priority && !VALID_PRIORITIES.includes(body.priority)) {
-    return `priority must be one of: ${VALID_PRIORITIES.join(', ')}`;
+    return `priority must be one of: ${VALID_PRIORITIES.join(", ")}`;
+  }
+  if (
+    body.assignee !== undefined &&
+    (typeof body.assignee !== "string" || body.assignee.trim() === "")
+  ) {
+    return "assignee must be a non-empty string when provided";
   }
   if (body.dueDate && isNaN(Date.parse(body.dueDate))) {
-    return 'dueDate must be a valid ISO date string';
+    return "dueDate must be a valid ISO date string";
+  }
+  return null;
+};
+
+const validateAssignee = (body) => {
+  if (
+    !body ||
+    typeof body.assignee !== "string" ||
+    body.assignee.trim() === ""
+  ) {
+    return "assignee is required and must be a non-empty string";
   }
   return null;
 };
 
-module.exports = { validateCreateTask, validateUpdateTask };
+module.exports = { validateCreateTask, validateUpdateTask, validateAssignee };