base on Runtime introspection and unit testing of SwiftUI views <h1 align="center">ViewInspector 🕵️‍♂️ for SwiftUI</h1> <span align="center">  [](https://codecov.io/gh/nalexn/ViewInspector) </span> **ViewInspector** is a library for unit testing SwiftUI views. It allows for traversing a view hierarchy at runtime providing direct access to the underlying `View` structs. ## Why? SwiftUI view is a function of state. We could provide it with the input but could not verify the output... Until now! ## Helpful links * **[Inspection guide](guide.md)** * **[SwiftUI API coverage](readiness.md)** ## Use cases ### 1. Search the view of a specific type or condition Use one of the `find` functions to quickly locate a specific view or assert there are none of such: ```swift try sut.inspect().find(button: "Back") try sut.inspect().findAll(ViewType.Text.self, where: { try $0.attributes().isBold() }) ``` Check out [this section](guide.md#dynamic-query-with-find) in the guide for the reference. ### 2. Read the inner state of the standard views Standard SwiftUI views are no longer a black box: ```swift let sut = Text("Completed by \(72.51, specifier: "%.1f")%").font(.caption) let string = try sut.inspect().text().string(locale: Locale(identifier: "es")) XCTAssertEqual(string, "Completado por 72,5%") XCTAssertEqual(try sut.inspect().text().attributes().font(), .caption) ``` Each view has its own set of inspectable parameters, you can refer to the [API coverage](readiness.md) document to see what's available for a particular SwiftUI view. ### 3. Verify your custom view's state Obtain a copy of your custom view with actual state and references from the hierarchy of any depth: ```swift let sut = try view.inspect().find(CustomView.self).actualView() XCTAssertTrue(sut.viewModel.isUserLoggedIn) ``` The library can operate with various types of the view's state, such as `@Binding`, `@State`, `@ObservedObject` and `@EnvironmentObject`. ### 4. Trigger side effects You can simulate user interaction by programmatically triggering system-control callbacks: ```swift try sut.inspect().find(button: "Close").tap() let list = try view.inspect().list() try list[5].view(RowItemView.self).callOnAppear() ``` The library provides helpers for writing asynchronous tests for views with callbacks. ## FAQs ### Which views and modifiers are supported? Check out the [API coverage](readiness.md). ### Is it using private APIs? **ViewInspector** is using the official Swift reflection API to dissect the view structures. So it'll be production-friendly even if you could somehow ship the test target to the production. ### How do I add it to my Xcode project? Assure you're adding the framework to your unit-test target. **Do NOT** add it to the main build target. #### Swift Package Manager `https://github.com/nalexn/ViewInspector` #### Carthage `github "nalexn/ViewInspector"` #### CocoaPods `pod 'ViewInspector'` ### How do I use it in my project? Please refer to the [Inspection guide](guide.md). You can also check out my other [project](https://github.com/nalexn/clean-architecture-swiftui) that harnesses the **ViewInspector** for testing the entire UI. ### Contributions Contributions are welcomed! If you see an unsupported view or modifier, you can either open an issue (so I could prioritize such SwiftUI APIs over the rest), or try to crack it yourself: use the `print("\(Inspector.print(<#view#>) as AnyObject)")` as the starting point of the investigation. ", Assign "at most 3 tags" to the expected json: {"id":"10864","tags":[]} "only from the tags list I provide: []" returns me the "expected json"