This is a simple iOS project developed for a tech-challenge.

The aim for this was to fetch a Pokemon list from an external source, with a paginated request being displayed in an infinite scroll list, and on tapping one of the Pokemons, display a detail screen with its evolution chain.

Application

Pokemon Species	Pokemon Details

Tech Stack

Interfaces

Interfaces were built with UIKit, 100% manually coded, without the usage of any Storyboards or XIBs.

This decision was made thinking on scalability, since in greater projects Storyboards can bring many conflicts issues in merge requests.

There's a simple code to enhance the readability of the constraints setting, making it as easy as:

private func setUpConstraints() {
    view.addSubviews(imageView, tableView)
    
    imageView
        .top(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 24)
        .centerX(equalTo: view.centerXAnchor)
    
    tableView
        .constraint(.leading, .trailing, .bottom, equalTo: view)
        .top(equalTo: imageView.bottomAnchor, constant: 24)
}

This was built on a UIView extension, no external dependencies were added for it.

Network

No additional framework were added for networking. For scaling and reusability purposes, a custom network layer was built.

Since the application only made simple GET requests, it wouldn't make sense to add heavy networking frameworks. Instead of this, it was created a structure with Routers inspired on Moya's routing system, but without the need to rely on Alamofire.

Using async-await for handling the asynchronous requests made the networking as easy as:

let result = await pokeAPIService.getEvolutionChain(forSpecieID: specie.id)

Strings

Strings in the application are localized. To avoid writing manually the localization identifiers in multiple places of the app, a LocalizedString enumeration was created and a custom initializer was added to String.

With this simple structure, localization got as easy as:

title = String(LocalizedString.speciesListTitle)

UI Design Pattern

The MVP-C was chosen as the UI Design Pattern since it's more fittable with the stack and provides enough isolation for unit testing.

Unit Testing

Quick & Nimble were used for the Unit Testing, to provide a better readability for the test cases, and make errors also easier to understand due to the better messages.