kunaakos / gli

interview assignment

Exchange Rates App

Goals

I was shooting for finishing this in one afternoon or the equivalent of a workday, which includes reading the docs, setting up boilerplates, and coming up with a design.

See the app live here.

Design / UX

I usually just implement and tweak designs, but whenever I have to make something look like anything, I go with a minimalist, brutalist look - because that's what I personally like, and it's also real fast for prototyping.

UX-wise the app is pretty standard, there's two tiny details that I very much like, but would drive any user (or product person) crazy in a real world situation:

1. the border on the left of currency cards acts as a flagpole if there's an icon available :D
2. search is case-sensitive, UPPERCASE will match currency codes (e.g. AUD), lowercase will match currency names

... but this isn't the real world, so I went with it!

I used a not so common but pretty nice approach to handling different screen sizes: try zooming out!

Assets

I ended up not using the provided flags, because they had country codes instead of currency codes, and I wanted to go with an inlined SVG solution anyways. Inlining SVGs didn't work out without ejecting the app or digging deeper into the CRA docs and hacks maybe, but I stuck with SVGs because I wanted to be able to resize flag icons however I see fit without seeing pixels. I only added a small handful of flags to the assets, and wouldn't spend much time adding more until I had a script handling SVG optimization and inlining, but that's a significant chunk of work in itself.

Tooling

I went with CRA for scaffolding the application, because it's the default and a very good tool to go to. It had all the tooling I needed and made it easy to set up regression testing. I wrote a standard react app in TypeScript. For styling I used emotion, because paired with a component-based approach and a properly executed UI library it makes meaningful visual regression testing possible (components in this app will render exactly as in the test, if the same default fonts are provided).

Testing

There's not much functionality to test, so I picked one component, the CurrencyCard. I'm checking how it handles incomplete data, and did some visual regression testing - which I find very useful for front ends of real-world applications, especially when introducing major changes. They also give developers really useful input about how components failed.

Conventions

I threw in a .prettierrc for basic indentation and style rules, and went with defaults for the rest. I don't like making formatting decisions, but I love consistency, so I love a good opinionated linter/formatter.