❗When you have finished working on your submission, reply back to the email with the recruiter with a link to your repository fork.

Build a universial iOS app that queries GitHub for repositories that mention the phrase GraphQL.

The code necessary to communicate with and parse the results from GitHub have been provided for you.

Your responsibility is to showcase your ability to build a great UI/UX for interacting with the data provided in ~4 hours.

Please explain in a README file the choices you made to complete the code challenge and list the things you would have added if you had more time to spend on it.

Fork this project and clone it to your local machine.

Dependencies are managed with Swift Package Manager. After opening Xcode, you should see it resolving dependencies.

You will need a Personal Access Token for GitHub to run the project. Update the variable kGitHubBearerToken in the Networking/ApolloClient.swift.

You are allowed to use 3rd party libraries as dependencies, but you should explain somewhere what problem(s) they solve and why you selected the specific library you did.

Any new dependencies should also be managed by SwiftPM.

Use your best judgement, as the point of this project is to showcase YOUR abilities.

The following are hard requirements. Every requirement is expected to be completed with your submission.

1. Initial launch: fetch the initial set of repos that contain the string graphql
2. Display the result of each repository returned from the query
3. Infinite scrolling - when reaching the bottom of the currently loaded dataset, the query should continue from the last point
4. Error handling - let the user know when an error happens
5. MVVM architecture

There are NO explicit requirements to use Combine, async/await, RxSwift, SwiftUI, UIKit or any other particular framework or library. It is up to you to use what you feel showcases your strengths the best.

If you have time, go above and beyond to show us your skills further by adding unit tests or new features.

This project has already provided the networking code that uses the Apollo iOS client to fetch data from the GitHub GraphQL API.

There are two conformances to the GraphQLClient protocol: ApolloClient and MockGraphQLClient.

ApolloClient is the type provided by Apollo-iOS and is to be used at runtime. There is the static shared extension for getting a ready-made instance.

MockGraphQLClient is a client for returning mocked data in unit tests.

All GraphQLClient conformances have the following method for searching repositories:

@discardableResult
func searchRepositories(
  mentioning phrase: String,
  filter: SearchRepositoriesQuery.Filter? = nil,
  cachePolicy: CachePolicy = .returnCacheDataAndFetch,
  contextIdentifier: UUID? = nil,
  queue: DispatchQueue = .main,
  resultHandler: @escaping (Result<RepositorySearchResult, Error>) -> Void
) -> Cancellable {

// example of basic usage
self.client.searchRepositories(mentioning: phrase) { response in
  switch result {
  case let .success(results): print(results)
  case let .failure(error): print(error)
}

Note: By default this completion handler needs to be re-entrant safe - it can be invoked 1-2 times for the same query as it will first return cache data (if available) and the server's response.

This method itentionally uses a completion handler in order to give you freedom to handle asynchronous programming however you see fit - async/await, Combine, RxSwift, or other UIKit patterns.

There are a few testing helpers to get started with writing unit tests.

To create individual node results, use the SearchQueryNode.makeRepository(name:owner:stargazersCount:) factory method.

If you need to create a bunch of edge nodes - use the free function makeEdges(count:_:).

In your unit tests, you can instantiate a MockGraphQLClient and pass it to the ViewModel as such:

let mockedResponse: SearchRepositoriesQuery.Data = // ...
let viewModel = ViewModel(client: MockGraphQLClient<SearchRepositoriesQuery>(response: mockedResponse))