cabify

Cabify backend test

Resolution

This resolution in this repository is the one for Cabify Backend Challenge And was thought in these steps:

1. Analysis of the problem
2. Environment setup. Repository with CI via gitlab and gitlab pipelines
3. Was written using TDD for most of the core packages.
4. Overall testing and documentation writing

Databases are all objects (dictionaries) in memory, as the exercise described. Besides this solution fits the problem, in a real world scenario i would use:

• Redis: for basket memory, to provide a fast, scalable and reliable source for user sessions and their baskets
• Postgres: for products and strategies database, as it's a simple yet reliable datastore

Requirements

• Node v11.0.0
• Go 1.11.1 To run the server locally
• Docker 18.06.01-ce

Those versions are development tested. Despite it may work with earlier versions, i recommend using this

Run

You can run it with docker via:

docker build -t rburdet/cabify .
docker run -it --rm -p 3000:3000 rburdet/cabify

Or locally using make via:

make
make run

You can see what other commands are available by running make help

You can run the client via:

cd cli
npm i
npm start

Considerations

• Promotion order matter, so applying bulk and then 2x1 is different as applying 2x1 and then bulk.
• This promotions are loaded in a (mocked) database, production code should be a microservice for asking discounts strategies.
• I didn't work using git flow because it was me alone on this project and i saw no gains in using it.
• Dockerfile has a multi stage build to provide smaller images size, this one is 16.1MB.

Client

Client is a simple CLI made with Node.js, its a simple index file with inquirer handling user input.

Future work

On the server:

• Today baskets doesnt expire or finish ( as it wasn't an exercise requirement ). I should use TTLs on them and accept finishing a session/basket.
• There aren't many safity checks for edge cases, like posting to a non existent basket, will do nothing but wont notify anything weird. I should implement http 4xx and 5xx cases, and a better logging logic.

On the client:

• all the configuration is static.
• While the server keeps a basket ID in which you can make your operations at any time, the client generates a basket ID with every execution, you could think about it like a new session.
• I used promises and async/await to show that i can use both of them.