FS-dev Sequence Generator(s)

A full stack application which creates pseudo generator functions based on sequencer functions that have been implemented here.

The back end is done in:

• NodeJS and Express.
• For testing, Mocha and the Node Assertion Library where used.

The front end is done in:

• React
• Redux along with;
• Redux-Thunk: allow for returning action creators instead of just plain actions
• Redux-Logger: Logger for redux.
• Redux-Dev-Extension-Tools: For debugging purposes
• Jest and Enzyme are used for testing
• Also used Animate.css for animations

Design

For this project, I decided to go by way of developing a REST backend which provides data to the frontend client. I went with this particular method of design due to the following:

• Scalability: Due to the separation of the backend(server) and frontend(client), the product can easily be scaled by any other developer
• Portability: Again due to the separation of concerns, the server and client can be hosted on different servers.
• Also, this particular design allowed for me to focus on one thing at every point in time and I can easily extract the generators/sequencers and use in other projects.

Work Progress

• Worked mostly using TDD. Have 2 branches; master and develop.
• The master branch has the best version of the code and the develop branch has the most recent changes and that's where active development takes place.
• List of commits and work progression can be found here

Assumptions/Corners

• I assumed the correct data will always be sent to the sequencers and as such didn't focus too much on error handling in fail cases

• I also assumed limits when it came to the prime number sequencer(10000 prime numbers).

• As for corners, I implemented the frontend before writing the unit tests.

• I also hardcoded the start and step values for my range number sequencer, I did same for the partial sum sequencer. This is because taking these as parameters caused my sequencer to only return the first number and I was taking too long to debug the issue.

Production

• Application is hosted on both Heroku and firebase(kept getting errors when hosting frontend on Heroku).
• Frontend application is found here
• Backend application link is :-)

Development

docker-compose up

For development, the server/ and client/ directories have their own docker containers, which are configured via the docker-compose.yml file.

The client server is spun up at localhost:3000

The local directories are mounted into the containers, so changes will reflect immediately. However, changes to package.json will likely need to a rebuild: docker-compose down && docker-compose build && docker-compose up.

Notes

Installing npm dependencies

All changes to node_modules should happen inside the containers. Install any new dependencies inside the container. You can do this via docker-compose run, but it’s easier to just update a running container and avoid having to rebuild everything:

docker-compose exec client

Then inside:

npm install --save <new_dependency>

Difficulties

• Hosting the application on Heroku is proving difficult.
• Implementing the logic for the piped sequence
• Implementing Partial Sum Sequencer
• Making full use of generators in the frontend
• TDD for react

Future Work

• Make API RESTful
• Perfect and rework sequencers using actual generators or maybe I'll use async/await
• Better the client application
• Move client to separate repository
• Increase code coverage in both server and client applications

Setup references

References for setting up a Node project with Docker and docker-compose:

• https://nodejs.org/en/docs/guides/nodejs-docker-webapp/
• https://github.com/mrcoles/node-react-docker-compose/blob/master/README.md

Express + React:

• https://medium.freecodecamp.org/how-to-make-create-react-app-work-with-a-node-backend-api-7c5c48acb1b0