1. ViperModule folder: I assume this small app is just a module of a large app. So I called it ViperModule, which contains files for VIPER classes for this module. "VP" prefix indicates Invest.

2. Network folder: Since there is no actual network calls for this demo app, I created a MockURLSession, which simulates the network call. It will return the json file as repsonse after 1.5 sec

3. Helpers folder: Other helper classes which could benefit all modules in one large project.

VPViewController has four states: loading, loaded, error and noData to display different views.

1. AppDelegate will first generate a instance of VPViewController through VPRouter class

2. VPViewController calls viewDidLoad, VPViewController has loading state.

2. VPViewController make the calls to fetchVipers in ViewDidLoad

3. VPViewController ask VPPresenter to fetchVipers through VPPresenterInputProtocol

3. VPPresenter notifies VPInteractor class through VPInteractorInputProtocol

4. VPInteractor interact with low level ApiConnection class to make mock network calls and get either success json response or error through ApiConnectionProtocol

5. ApiConnection notifies VPInteractor the raw json data through ApiconnectionOutputProtocal

6. VPInteractor converts the raw json data to ViperModel and notifies VPPresenter the results through VPPresenterOutputProtocal

7. VPPresenter converts the ViperModel to VPViewModel and notifies VPViewController through VPViewControllerProtocol

8. VPViewController will update its state based on the results and updates UI based on the value from VPViewModel

9. TableView will reload data from VPViewModel

10. VPImageView will get image url from VPCellViewModel

11. VPImageView will check if the image has been cached from ImageCacheManager through ImageCacheManagerProtocol

12. If image is not cached, VPImageView will ask ImageDownloadManager to download the image through ImageDownloadManagerProtocol

13. ImageDownloadManager will ask low level ApiConnection class to download the image through ApiConnectionProtocal

14. Once the image is downloaded, ApiConnection will notify ImageDownloadManager through ApiconnectionOutputProtocal

15. ImageDownloadManager will notify VPImageView the response through VPImageViewOutputProtocol

16. VPImageView will update image and cache the image to ImageCacheManager through ImageCacheManagerProtocol

17. While image is downloading and the tableViewCell end displaying, VPImageView will ask ImageCacheManger to cancel downloading image througth ImageDownloadManagerProtocol

18. ImageCacheManger will ask low level ApiConnection class to cancel download the image through ApiConnectionProtocal

1. ApiconnectionTest class has following tests:

	testGetResumeCalled
	testURLStrSame
	testShouldReturnData
	testShouldReceiveError
	testRequestCancel

2. VPInteractorTest class creates mock VPPresenter and mock Apiconnection with following tests:

	testFetchVipersSucceed
	testFetchVipersFails

3. VPPresenterTest class creates mock VPInteractor and mock VPViewController with following tests:

	testFetchVipersSucceed
	testFetchVipersFail

4. VPRouterTest class has the following tests:

	testRouterGenerateAllElements
	
5. VPViewControllerTest class creates mock VPPresenter with the following tests:

	testInitialState
	testFetchVipersFail
	testFetchVipersSucceed
	testFetchVipersNoContents
	testLoadingStateUI
	testLoadedStateUI
	testNoDataStateUI
	testErrorStateUI

6. VPLoadingViewTest has the following tests

	testShow
	testHide

7. VPMsgViewTest has the following tests

	testShow
	testHide

8. VPImageViewTest class creates mock ImageCacheManager and MockDownloadManager with the following tests:

	testImageDownloadSucceed
	testImageDownloadError
	testImageDidCache
	testImageDownloadCancel
	testGetImageFromCache
	testGetImageWithEmptyURL

9. VPVipersDataSourceTest creates mock VPViewModel with the following tests:

	testNumberOfRows
	testTableViewCellData

10. VPViewModelTest has the following tests:

	testGetOverviewTitleHasData
	testGetOverviewTitleHasNoData
	testHasVipersData
	testHasNoVipersData
	testVipersCount
	testGetCellViewModelSucceed
	testGetCellViewModelFail

11. VPCellViewModelTest has the following tests:

	testHasImageURL
	testHasNoImageURL
	testHasLevel
	testHasNoLevel
	testHasIsAccessible
	testHasNoAccessible