Merge pull request #5 from bookingcom/gtarasov/if_in_introspection

Fix SwiftUI root view introspection for `if` conditions

PerformanceSuite/Sources/RootViewIntrospection.swift

@@ -46,7 +46,7 @@ final class RootViewIntrospection {
     /// Looking for all the meaningful views in the hierarchy.
     /// Method similar to `rootView(view:)`, but it looks deeper into the hierarchy and looks not for the single child,
     /// but for all possible meaningful views.
-    /// For example, it takes all the children of `VStack { ... }`, takes both values of `.if(...)`, etc.
+    /// For example, it takes all the children of `VStack { ... }`, `HStack { ... }`, etc.
     /// - Parameter view: view hierarchy to look up in
     /// - Returns: all children views we consider meaningful
     func meaningfulViews(view: Any) -> [Any] {
@@ -64,26 +64,31 @@ final class RootViewIntrospection {
 
         if hadChild {
             return result
+        } else if mirror.displayStyle == .optional && mirror.children.isEmpty {
+            // this is an optional value with nil inside, return nothing
+            return []
         } else {
+            // no children found, returning view itself
             return [view]
         }
     }
 
     private let possibleRootChildAttributeNames: Set<String?> = [
         "some",  // is used in Optional<SomeView>
-        "storage",  // is used in AnyView
+        "storage",  // is used in AnyView, Text
+        "anyTextStorage", // is used in Text
         "view",  // is used in AnyViewStorage
         "content",  // is used in ModifiedContent
         "base", // is used in ModifiedElements
         "_tree", // is used in VStack/HStack
         "tree", // is used in LazyVStack/LazyHStack
         "value", // is used in TupleView
         "custom", // is used in Base
+        "trueContent", // is used in `if ... else ...`
+        "falseContent", // is used in `if ... else ...`
     ]
 
     private let possibleMeaningfulChildAttributeNames: Set<String?> = [
-        "trueContent", // is used in `if ... else ...`
-        "falseContent", // is used in `if ... else ...`
         ".0", ".1", ".2", ".3", ".4", ".5", ".6", ".7", ".8", ".9", // are used in view builders with multiple children
         "elements", // is used in _ViewList_View
     ]

PerformanceSuite/Tests/RootViewIntrospectorTests.swift

@@ -15,6 +15,12 @@ class RootViewIntrospectionTests: XCTestCase {
 
     private let introspector = RootViewIntrospection()
 
+    func testMyView() {
+        let view = MyView()
+        let rootView = introspector.rootView(view: view)
+        XCTAssert(rootView is MyView)
+    }
+
     func testAnyView() {
         let view = AnyView(MyView())
         let rootView = introspector.rootView(view: view)
@@ -67,7 +73,47 @@ class RootViewIntrospectionTests: XCTestCase {
         }
     }
 
+    func testIfViewTrue() {
+        condition = true
+        let controller = UIHostingController(rootView: ifView)
+        let root = controller.introspectRootView()
+        XCTAssert(root is MyFirstView)
+    }
+
+    func testIfViewFalse() {
+        condition = false
+        let controller = UIHostingController(rootView: ifView)
+        let root = controller.introspectRootView()
+        XCTAssert(root is MySecondView)
+    }
+
+    var condition: Bool = false
+
+    @ViewBuilder var ifView: some View {
+        if condition {
+            MyFirstView()
+        } else {
+            MySecondView()
+        }
+    }
+
+    private struct MyFirstView: View {
+        var body: some View {
+            Text("first")
+        }
+    }
+
+    private struct MySecondView: View {
+        var body: some View {
+            Text("second")
+        }
+    }
+
     private struct MyView: View {
+        // adding some props to make sure Mirror.children are not empty
+        let prop1 = "my_prop1"
+        var prop2 = 2
+
         var body: some View {
             Text("blablabla")
                 .frame(width: 10, height: 20, alignment: .center)
@@ -101,11 +147,26 @@ class RootViewIntrospectionTests: XCTestCase {
         XCTAssertEqual("MyViewController", introspector.description(viewController: myController))
     }
 
+    func testDescriptionForText() {
+        let controller = UIHostingController(rootView: Text("my text"))
+        XCTAssertEqual("LocalizedTextStorage", introspector.description(viewController: controller))
+    }
+
+    func testDescriptionForTextWithModifier() {
+        let controller = UIHostingController(rootView: Text("my text").onAppear { })
+        XCTAssertEqual("LocalizedTextStorage", introspector.description(viewController: controller))
+    }
+
     func testDescriptionForSimpleView() {
         let controller = UIHostingController(rootView: MyView())
         XCTAssertEqual("MyView", introspector.description(viewController: controller))
     }
 
+    func testDescriptionForSimpleViewWithModifiers() {
+        let controller = UIHostingController(rootView: MyView().onAppear { }.onDisappear { }.onTapGesture { })
+        XCTAssertEqual("MyView", introspector.description(viewController: controller))
+    }
+
     func testDescriptionForComplexView() {
         let controller = UIHostingController(rootView: makeComplexView())
         XCTAssertEqual("MyView", introspector.description(viewController: controller))
@@ -116,6 +177,18 @@ class RootViewIntrospectionTests: XCTestCase {
         XCTAssertEqual("InputText, SearchDestinationList, ProgressView", introspector.description(viewController: controller))
     }
 
+    func testDescriptionForVeryComplexViewWithConditionsTrue() {
+        condition = true
+        let controller = UIHostingController(rootView: makeComplexViewWithConditions())
+        XCTAssertEqual("InputText", introspector.description(viewController: controller))
+    }
+
+    func testDescriptionForVeryComplexViewWithConditionsFalse() {
+        condition = false
+        let controller = UIHostingController(rootView: makeComplexViewWithConditions())
+        XCTAssertEqual("SearchDestinationList, ProgressView", introspector.description(viewController: controller))
+    }
+
     @ViewBuilder private func makeVeryComplexView() -> some View {
         LazyHStack {
             EmptyView()
@@ -160,6 +233,57 @@ class RootViewIntrospectionTests: XCTestCase {
             }
         }
     }
+
+    @ViewBuilder private func makeComplexViewWithConditions() -> some View {
+        LazyHStack {
+            EmptyView()
+            Button("my title", action: { })
+            VStack {
+                EmptyView()
+                ZStack {
+                    if condition {
+                        CardContainer {
+                            HStack {
+                                Button("Button") {
+                                    print("Button Tapped")
+                                }
+                                .padding()
+                                .background(Color.blue)
+                                .zIndex(1.0)
+                                if !condition {
+                                    AnyView(SearchDestinationList())
+                                }
+                                InputText()
+                                    .accessibility(identifier: "inputText")
+                                    .font(.callout)
+                                    .autocorrectionDisabled()
+                            }
+                        }
+                        .overlay(
+                            RoundedRectangle(cornerRadius: 16)
+                                .stroke(lineWidth: 2)
+                                .foregroundColor(.gray)
+                        )
+                        .padding()
+                        .padding()
+                        .zIndex(1.0)
+                    } else {
+                        if !condition {
+                            AnyView(SearchDestinationList())
+                        }
+
+                        VStack {
+                            ProgressView()
+                                .padding()
+                            Spacer()
+                        }
+                    }
+                }
+                Spacer()
+                EmptyView()
+            }
+        }
+    }
 }
 
 private class MyViewController: UIViewController { }