README.md

HackYourFuture Node.js Week 1 - Homework

Instructions

0. Prerequisites
1. Fork this repository
2. Make new branch called your-username-homework
3. Install dependencies
4. Read and do the assignment until all tests pass
5. Make a pull request in this repository

Prerequisites

You need to have Node.js > 8.x installed. Check main README for instructions on how to do that.

Installing dependencies

Change to the directory where you've cloned this repository, then to week1/homework directory and finally install dependencies:

cd path/to/your/cloned/repo
cd week1/homework

yarn

# or

npm install

Running tests

Depending your package manager, you can run the tests using:

yarn test

# or

npm test

Try and run the tests without writing any code first. You will see that all the tests will fail:

  ✖ /state returns 10 Expected server to respond without an error, got Timeout of 100ms exceeded
  ✖ /add returns 11 Expected server to respond without an error, got Timeout of 100ms exceeded
  ✖ /subtract returns 9 Expected server to respond without an error, got Timeout of 100ms exceeded
  ✖ /reset returns 10 Expected server to respond without an error, got Timeout of 100ms exceeded
  ✖ /add, /reset returns 10 Expected server to respond without an error, got Timeout of 100ms exceeded
  ✖ /subtract, /reset returns 10 Expected server to respond without an error, got Timeout of 100ms exceeded
  ✖ /add, /add, /add, /subtract returns 12 Expected server to respond without an error, got Timeout of 100ms exceeded
  ✖ /subtract, /subtract, /reset, /add, /subtract, /add returns 11 Expected server to respond without an error, got Timeout of 100ms exceeded
  ✖ /add, /add, /add, /add, /add, /add, /add, /add, /add, /add returns 20 Expected server to respond without an error, got Timeout of 100ms exceeded
  ✖ /subtract, /subtract, /subtract, /subtract, /subtract, /subtract, /subtract,/subtract, /subtract, /subtract returns 0 Expected server to respond without an error, got Timeout of 100ms exceeded
  ✖ querying undefined URL returns 404 Not Found Expected server to respond without an error, got Timeout of 100ms exceeded

  11 tests failed

Then write the code as required by the assignment and run the tests again. Fix any issues until all tests pass.

  ✔ /state returns 10
  ✔ /add returns 11
  ✔ /subtract returns 9
  ✔ /reset returns 10
  ✔ querying undefined URL returns 404 Not Found
  ✔ /add, /reset returns 10
  ✔ /subtract, /reset returns 10
  ✔ /add, /add, /add, /subtract returns 12
  ✔ /subtract, /subtract, /reset, /add, /subtract, /add returns 11
  ✔ /add, /add, /add, /add, /add, /add, /add, /add, /add, /add returns 20
  ✔ /subtract, /subtract, /subtract, /subtract, /subtract, /subtract, /subtract, /subtract, /subtract, /subtract returns 0

  11 tests passed

Before submitting your homework via a pull request, make sure that your server passes all the unit tests as described above.

Run the project

In week1/homework run:

node .

You can interactively test the endpoints with a browser or by using Postman.

Assignment

Create an HTTP server that can add and subtract from a number, which we will call state. Use the project in week1/lecture directory for reference.

State should be persisted between individual calls and not reset before each one.

Rule 1

Your modifications should be limited to the src folder. Do not make any changes to the test folder.

Rule 2

DO NOT USE EXPRESS.JS

Rule 3

You can use other packages, but the server must be implemented using the built-in http module.

Endpoints to implement

/state

Returns the current state in JSON format. When the server starts, this should return '10'. Example:

{
  "state": 10
}

/add

Increments state by 1 and returns it JSON format. Example:

{
  "state": 11
}

/subtract

Decrements state by 1 and returns it JSON format. Example:

{
  "state": 9
}

/reset

Resets state to 10 and returns it JSON format. Example:

{
  "state": 10
}

Any other URL results in an error with status code 404 and response body in JSON format:

{
  "error": "Not found"
}