PixaBay

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PixaBay

The architecture used to build PixaBay app is MVVM, with helping hands from RxSwift. The navigation is handled by a coordinator. It is responsable to remove navigation logic from each view and have them all in just one place.

i created a project for each feature which has 2 frameworks:

1. Presentation: which contains all the iOS files and views
2. Network: Which contains the api endpoints
3. Cache can be added as well or other frameworks but in this project it wasn't needed

each feature can be selected as a target and ran on the simulator

the DI Container resolves the HTTPClient to the URLSessionHTTPClient and the repositories to their corresponding objects .

Third-party Libraries

Resolver Dependency injection framework for Swift.

SVProgressHUD Loader Animation

AJMessage View To display Error Messages

References

1. Essential Developer youtube channel and course
2. danielt1263 repositories

Views Overview

All views are created using storyboards where they are instantiated using a decoder and a viewModel

Login

The Login View has 2 fields (Email and Password) which both inherit ErrorTextField,TextFieldRule where each once has it owns Validation policy and when it's valid the errorLabel appears and when it's not it becomes Hidden when Both TextField Are Valid the LoginButton becomes enabled

The LoginViewModel handles the state of each textfield , and has an injected UserRepository that contains all the requests for the Registration, The Correct credentials are [email protected] and 123456

The ScrollView bottom insets is Binded to the KeyboardHeight The LoadingAnimation is Binded to the loaderSubject that exists in the viewModel The LoginCoordinator handles the transition to the RegistrationView and asWell as transition to the HomeView

Registration

The Registration has 3 fields (Email,Password,Age) where each has its own validation policy same as the LoginView, it's similar to the login screen in terms of validation , Loading behavior and architecture

Home

The HomeView contains Images downloaded From pixabay. Instead of waiting to scroll to load the images i preload them in advance, and if the cell has ended Displaying i cancel the download or cancelPrefetchingForRowsAt has been called

Network

The mapping is done in the ResponseMapper where it has an injected DecodedType which is the Decodable object , URLResponse and Data if the status code isn't 200, the api error is returned with a custom message according to the response status code.

Unit Tests

All Tests covered handle retain cycles, i set a weak variable value to an instance and observe its value when the test is completed the instance should be nil thus the weak variable as well , if not then we would have a retain cycle . any by using Leaks i made sure there are no leaks as well (trackForMemoryLeaks in XCTestCase+MemoryLeakTracking)

 

PixaBaySnapshotsTests:

I use the func record to take a screenshot of the view for LightMode and DarkMode and save it in the same directory of the test, then i use assert func to make sure that the new screenshot is the same as the old value .Usually i use this test to quickly check the change for each Language and Appearance for each view.

The PixaBayTests:

TextFields:

Handled all states to check if it's valid or not as well as checking the error Label

ViewModels:

Handled all states to check if the loginButton or Registration Button will get enabled

ImageDetails:

Assert That the injected ViewModelValues are the same as the ImageDetails Label Text

HomeView:

 1)`RefreshControl` is Visible and Refreshing on start
 2)on Refresh the viewModel calls the Repository to getData (Using a repositorySpy to observe that the call has been made)
 3)Received item is properly rendered on Screen (Get the cell from tableView and compare the values of model and tableViewCell)
 4)Test Preload and `cancelPreload` and `DidEndEditing` if it will cancel the APiRequest(check the SubscribeBlock on disposed if it gets called)
 5)OnError the `retryButton` is visible (Emitting an Error from the `PixaBayRepositoryMock` and  checking the cell if its `retryButton` is visible)
 6) OnErrorPress the image gets downloaded ( Using a `repositorySpy` to check if the Api function is called)
 7) Check if the image is Animating at start (Check if the View `layer.mask.animation(forKey: shimmerAnimationKey) != nil`)
 8) Check if an image that exists in the `DocumentsDirectory` will be used instead of downloading it from the internet
 9)Check if an image that doesn't exist in the `DocumentsDirectory` will be downloaded and saved in the Documents

Scene Delegate:

Check if the window is visible and the loginViewController is the rootViewController

Coordinators:

Tested the start function and the navigation for each Coordinator

PixaBayNetworkTests

-Tested the ResponseMapper for each status code , and for a valid and invalid Data

-Stubbed the URLSession where i used the URLProtocol to set a custom Response using the URLProtocolStub