This application allows users to browse a list of characters in the main page, and then navigate into each character's page to see the comics details involving this particular character. The users are also capable of posting/deleting comments in the character detail page. Data for this app is from Marvel API.

1. As a user, I can view a list of characters in the main page.
2. I can always press the ">" button to navigate down the list of characters.
3. As a user, I can view the comics details of a particular character.
4. Related characters in the same comics are also listed in the detail page.
5. As a user, I can switch between the "characters" and "details" views as I want.
6. When I switch back to the "characters" view, I should be on the same "characters" page as when I left.
7. As a user, I can leave a comment on the "details" page, and I can delete the comments.

This is a single-page web application built using Node/Express as the backend, and Angular as the front end. MongoDB is used to persist the form data, and Redis is utilized to cache the most recently requested data by user from the Marvel API, as well as the comment data posted by users. Mocha and Chai are used for tests.

When a character list or details for a character was requested for the first time, a request will be sent to Marvel API to get response. The returned information is subsequently cached in Redis paired with an unique key. So the second time when the same information is requested, the response will be from the Redis cache layer, rather than the HTTP requests to the Marvel API. Information in the cache layer expires after 24 hours. The same rules apply to the comment data. Comments for a character is grouped and cached in Redis with the character id as the key. And when a comment is posted/deleted, data in MongoDB is updated and the comments in Redis for this particular character are updated as well to keep Redis in Sync with MongoDB.

NPM
Node.js
Express.js
Mongoose
Angular.js
MongoDB
Redis

Create a developer account in the Marvel API web page, where you will get your '''PRIVATE_KEY''' and '''PUBLIC_KEY". Create a file with the name of '.env' in the root directory. And list the following local environment variables:

PRIVATE_KEY=YOUR-PRIVATE-KEY
PUBLIC_KEY=YOUR-PUBLIC-KEY
MONGODB_URI=YOUR-MONGODB-URI

cd to the project directory and run npm start in the terminal.

Mocha
Chai

cd to the project directory and run npm test in the terminal.