Description

This is a basic proof of concept for a Url Shortener App. It has the following components:

• A Golang-based API, backed by a PostGres DB
  • The entry point for the API code is the main function in ./api/api.go
• A React-based web-app, which is served by the API.
  • Entry point: ./api/web/src/App.tsx

Setup

Currently, there are two configurations for running the app:

• Local Dev Environment - if want to edit the code
• Test Environment - if you want to test the code locally.

Both require Docker (along with docker-compose) to be available on one's machine.

Test Environment

This environment is primarily intended CI/CD purposes. That being said, you can run it locally with minimal setup. For examining the app, this is probably the best approach.

While in the root of the repo directory, run the following: docker-compose -f docker-compose.test.yml up.

It takes a moment to build the image. This builds the API code and places it on a Docker image. As part of this, it also builds the React web app, and places the optimized bundle in a static directory on the image. If docker-compose is successful, then you should be able to visit http://localhost:8080, and see a fully functioning webapp.

IMPORTANT: If you are running in this environment, it will not have hot-reloads available for server or client code. Any changes you make to the code WILL NOT BE VISIBLE to the docker container. To have hot-reloads enabled, see the Local Development environment below.

Local Development

This prioritizes using hot reloads for the api and web code. In addition to Docker, you will need both node and yarn installed on your machine.

In the root path of the repo, run the following command: docker-compose -f docker-compose.local-dev.yml up This will start the api in a local_development mode, with hot-reloads available for server code.

Run the following in a new shell:

cd ./api/web
yarn install
yarn start

The above commands will start the webapp on localhost:3000. Note it will still communicate with the server running on 8080 via a proxy. This will allow hot-reloads for the React web app.

IMPORTANT If you go to localhost:8080, you will not see your most recent changes for the web app. Instead, go to localhost:3000 for local testing purposes.

Integration Testing and CI/CD

For testing, the "Test Environment" is used. The .travis.yml file specifies testing configuration. Currently, integration tests have been prioritized over stand-alone unit tests.

There are some node-based integration tests in the ./testing directory. To run these, you will need to run yarn install. The tests can be run with yarn test. You can run these tests from the repo root directory via ./run-tests.sh

IMPORTANT: In order for the tests to successfully run, you will need to have the Docker-compose environment running. Otherwise, the tests will fail.

These tests will also be run the CI pipeline.

Items to Improve Scalability, Maintainability and Security

Next steps to improve stability and performance:

• Consistent URL validation between client and server-side code.
• Frontend: Improve Responsiveness.
• Frontend: Incorporate modern CSS lib, such as Tailwind or SCSS.
• Cookie-based auth to track users.
• Incorporate Swagger to reduce redundant client-side api code.
• Include Cypress-based browser tests to improve true e2e coverage.
• Look at caching mechanism (Redis/Memcache) for validating users.
• Look at more scalable/performant mechanism for reading short-urls (such as Redis or Cassandra/DynamoDB)