Week 04 - Offline Videos Assignment.md

Week 04 - Offline Videos

Assignment #1 - Your logic is like a doctor

Learn by doing, lets create an in memory hospital

You need to create 4 routes (4 things that the hospital can do)

1. GET - User can check how many kidneys they have and their health
2. POST - User can add a new kidney
3. PUT - User can replace a kidney, make it healthy
4. DELETE - User can remove a kidney

• What should happen if they try to delete when there are no kidneys?
• What should happen if they try to make a kidney healthy when all are already healthy?

Solution - https://gist.github.com/hkirat/7b78356bd28022aecd476d29f3e6645f

Assignment #2 - You need to create an express HTTP server in Node.js which will handle the logic of a file server.

• Use built in Node.js fs module

  The expected API endpoints are defined below,

1. GET /files - Returns a list of files present in ./files/ directory

   Response: 200 OK with an array of file names in JSON format.

   Example: GET http://localhost:3000/files

2. GET /file/:filename - Returns content of given file by name Description: Use the filename from the request path parameter to read the file from ./files/ directory

   Response: 200 OK with the file content as the response body if found, or 404 Not Found if not found. Should return File not found as text if file is not found

   Example: GET http://localhost:3000/file/example.txt

• For any other route not defined in the server return 404

Assignment #3 & #4 - You need to create an express HTTP server in Node.js which will handle the logic of a todo list app.

• Assignment #3 - Don't use any database, just store all the data in an array to store the todo list data (in-memory)

• Assignment #4 - Hard todo: Try to save responses in files, so that even if u exit the app and run it again, the data remains (similar to databases)

  Each todo has a title and a description. The title is a string and the description is a string.

  Each todo should also get an unique autogenerated id every time it is created

  The expected API endpoints are defined below,

1. GET /todos - Retrieve all todo items

   Description: Returns a list of all todo items.

   Response: 200 OK with an array of todo items in JSON format.

   Example: GET http://localhost:3000/todos

2. GET /todos/:id - Retrieve a specific todo item by ID

   Description: Returns a specific todo item identified by its ID.

   Response: 200 OK with the todo item in JSON format if found, or 404 Not Found if not found.

   Example: GET http://localhost:3000/todos/123

3. POST /todos - Create a new todo item

   Description: Creates a new todo item.

   Request Body: JSON object representing the todo item.

   Response: 201 Created with the ID of the created todo item in JSON format. eg: {id: 1}

   Example: POST http://localhost:3000/todos

   Request Body: { "title": "Buy groceries", "completed": false, description: "I should buy groceries" }

4. PUT /todos/:id - Update an existing todo item by ID

   Description: Updates an existing todo item identified by its ID.

   Request Body: JSON object representing the updated todo item.

   Response: 200 OK if the todo item was found and updated, or 404 Not Found if not found.

   Example: PUT http://localhost:3000/todos/123

   Request Body: { "title": "Buy groceries", "completed": true }

5. DELETE /todos/:id - Delete a todo item by ID

   Description: Deletes a todo item identified by its ID.

   Response: 200 OK if the todo item was found and deleted, or 404 Not Found if not found.

   Example: DELETE http://localhost:3000/todos/123

   • For any other route not defined in the server return 404

Assignment #5 - You have to create a middleware for logging the number of requests on a server

You have been given an express server which has a few endpoints.

Your task is to create a global middleware (app.use) which will maintain a count of the number of 
requests made to the server in the global requestCount variable

Assignment #6 - You have to create a middleware for rate limiting a users request based on their username passed in the header

You have been given an express server which has a few endpoints.

Your task is to create a global middleware (app.use) which will rate limit the requests from a user to only 5 request per second
- If a user sends more than 5 requests in a single second, the server should block them with a 404.
- User will be sending in their user id in the header as 'user-id'
- You have been given a numberOfRequestsForUser object to start off with which clears every one second

Assignment #7 - You have to create a middleware for logging the number of errors on a server

You have been given an express server which has a few endpoints.

Your task is to
1. Ensure that if there is ever an exception, the end user sees a status code of 404
2. Maintain the errorCount variable whose value should go up every time there is an exception in any endpoint