Facilitates mock data integration for applications, enabling runtime request mocking with JSON files. Supports scenario-based automation, customizable responses, and dynamic toggling between mocked and live server data.
LetSee provides an easy way to provide mock data to your iOS application. The main intention of having a library like this is to have a way to mock the response of requests on runtime in an easy way to be able to test all available scenarios without the need to rerun or change the code or put in the extra effort.
The idea is simple, Instead of writing too much code to provide mock data,
Scenario, So each time a new request arrives It will get the proper response based on the current scenario's step./azure/us/api/v2/orders to the /Mocks/orders so I don't need to create multiple empty subdirectories to mock that request responses.Staging, and Dev or other environments
If you are still using **CocoaPods**, don't worry SPM and CocoaPods can coexist and live alongside each other peacefully, just
so basically, to map mocks folders to these URLs:
you need to organize your mock folders like this:
and when an API request URL ends with one of those paths, LetSee makes all JSON files in that folder available on the run time for you to choose from. for example, when this request got intercepted https://someBaseURL/products, you can choose one of these mock responses success_productList.json, success_emptyList.json, sucess_listWithoutBanner.json to answer it.
You may notice that there is a .ls.global.json file in the root mock folder, It can be utilized to map your mocks structure to more complicated addresses. Let's assume that your requests have various paths, like these
{
"maps": [
{
"folder": "/products"
For now, the name of the JSON files can begin with these:
So you can create as many files as you want in the folders, and all those files will be parsed and ready for you to be chosen by You as a response to the request.
Add Scenarios Folder to your project(Optional)
Scenario lets you automate the responding, each Scenario has a steps property that describes the steps that this scenario takes. for example, We can define a scenario for Transfer Money , users there would be many API calls involved in that scenario:
by default, all the requests will be intercepted by LetSee (if the mock is enabled) and they will be waiting to get their response, and We need to select a mock response for them manually, but with Scenarios, LetSee will do it for us. LetSee passes through the scenario steps and once a new request arrives, LetSee responds to it with the current step of the scenario until all the scenarios steps get processed and then LetSee automatically disabled the scenario and the next requests will be intercepted normally and they will wait for the manual action.
having a Scenarios folder is an option, but if you provide LetSee with a path to your scenarios folder, it parses them and shows you a list of all available scenarios and you can mock your requests based on your preferred scenario. A Scenario is a .plist file and describes the steps of that scenario and the response JSON file name (which should exist in the Mock JSON files folder)
each step should have two properties that indicate the name of the folder containing the mock file and the file name
folder: name of the folder that contains the mock file
responseFileName: the full name of the JSON mock file
and where ever you are handling the server calls, you can do something like this
let task: URLSessionDataTask
#if RELEASE
// Calls the production server
task = URLSession.shared.runDataTask(with: request, completionHandler: completionHandler)
#else
if LetSee.shared.configuration.isMockEnabled {
task .shared.runDataTask(using: .shared, with: request, completionHandler: completionHandler)
} {
task .shared.dataTask(with: request, completionHandler: completionHandler)
}
task.resume()
in the above code, We checked if the mocking is activated, then we let the LetSee intercepts the request (so we can mock its response) otherwise, we will run the request normally. now run your application and enjoy it.
flow chart:
graph LR
A[New request] --> B{isMockingEnabled}
B --Yes--> C(LetSee)
B --No--> D((Normal API call))
C --> F{IsScenarioEnabled}
F --Yes--> G(NextStep)
F --No--> E((AvailableMocks))
G --Automatic--> H
E --Manually Select Reponse--> H
D --Server Responses--> H(Response to the request)
import LetSee
// Somewhere like Appdelegate cofig the LetSee
// Configs LetSee
LetSee.shared.config(LetSee.Configuration.init(baseURL: URL(string: "https://api.thecatapi.com/")!,
isMockEnabled: false,
shouldCutBaseURLFromURLsTitle: true))
LetSee.shared.addMocks(from: Bundle.main.bundlePath + "/Mocks/Mocks")
LetSee.shared.addScenarios(from: Bundle.main.bundlePath + "/Mocks/Scenarios")
// Configs LetSee window, it makes the LetSeeButton be appear on top
let letSeeWindow = LetSeeWindow(frame: window.frame)
letSeeWindow.windowScene = window.windowScene
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