egfwd-image-processing-api

Description

Create an image processing API that resizes and saves images to user specifications when visiting a URL, and caches out data if it already exists. this project is submitted for Advanced Full-Stack Web Development Nanodegree by udacity.

The scripts needed to test/start/build the application

Install required packages

npm install

to build the application and compile TS to JS

npm run build

to start the server in production/build

npm run start

to start the server in dev

npm run start-dev

to run tests

npm run test

to run lint and prettier

npm run lint
npm run prettier

Endpoints

localhost

http://localhost:3000/

/api/images

http://localhost:3000/api/images?filename=name&width=number&height=number

For example,
http://localhost:3000/api/images?filename=fjord&width=500&height=400

the endpoint takes 3 query parameters

• filename=name, where name must be a string of length > 0
• width=number, where width must be postive integer greater than 0
• height=number, where height must be postive integer greater than 0

Usage

1. image must be in images folder to be resized

2. to resize fjord.jpg image placed in images folder with width=500 and height=400, example below

http://localhost:3000/api/images?filename=fjord&width=500&height=400

3. the resized images will be placed in resizedImages folder with file name

filename_width_height.jpg
fjord_500_400.jpg

4. if the image already exists in resizedImage, it will be cached out without reprocessing.

Validation and Error Handling

I used express-validator to validate query parameters and make sure that

• filename exists in images folder, if not return a 400 status code with error message.
• width and height are positive integers and greater than 0, if not return a 400 status code with error message.

Packages and Dependencies

• express and express-validator
• fs and path
• jasmine and supertest
• prettier and lint
• typescript