Fix an issue where nested ScrollViews would not be detected properly (#69)

* Fix an issue where nested ScrollViews would not be detected properly
* Fix nested ScrollView issue on iOS 13
* Clean up implementation of siblingOrAncestorOfType to avoid extraneous searches
* Adjust naming for correctness
* Add nested ScrollView tests for macOS
This also fixes the same issue iOS had, where nested ScrollViews would not be correctly detected on macOS 11+
* Update UIKit ScrollView tests to match AppKit ones
* Add changelog entry for nested scrollview fixes
* Change NSScrollView lookup mechanism for macOS 10.15 to match UIKit behavior

CHANGELOG.md

@@ -7,6 +7,7 @@ Changelog
 - Add Github Action
 - Added `.introspectTextView()`.
 - Update CircleCI config to use Xcode 12.4.0
+- Fixed nested `ScrollView` detection on iOS 14 and macOS 11
 
 ## [0.1.2]
 

Introspect/Introspect.swift

@@ -244,6 +244,13 @@ public enum TargetViewSelector {
         }
         return Introspect.previousSibling(containing: TargetView.self, from: viewHost)
     }
+
+    public static func siblingContainingOrAncestor<TargetView: PlatformView>(from entry: PlatformView) -> TargetView? {
+        if let sibling: TargetView = siblingContaining(from: entry) {
+            return sibling
+        }
+        return Introspect.findAncestor(ofType: TargetView.self, from: entry)
+    }
     
     public static func siblingOfType<TargetView: PlatformView>(from entry: PlatformView) -> TargetView? {
         guard let viewHost = Introspect.findViewHost(from: entry) else {
@@ -251,7 +258,14 @@ public enum TargetViewSelector {
         }
         return Introspect.previousSibling(ofType: TargetView.self, from: viewHost)
     }
-    
+
+    public static func siblingOfTypeOrAncestor<TargetView: PlatformView>(from entry: PlatformView) -> TargetView? {
+        if let sibling: TargetView = siblingOfType(from: entry) {
+            return sibling
+        }
+        return Introspect.findAncestor(ofType: TargetView.self, from: entry)
+    }
+
     public static func ancestorOrSiblingContaining<TargetView: PlatformView>(from entry: PlatformView) -> TargetView? {
         if let tableView = Introspect.findAncestor(ofType: TargetView.self, from: entry) {
             return tableView

Introspect/ViewExtensions.swift

@@ -83,9 +83,9 @@ extension View {
     /// Finds a `UIScrollView` from a `SwiftUI.ScrollView`, or `SwiftUI.ScrollView` child.
     public func introspectScrollView(customize: @escaping (UIScrollView) -> ()) -> some View {
         if #available(iOS 14.0, tvOS 14.0, macOS 11.0, *) {
-            return introspect(selector: TargetViewSelector.ancestorOrSiblingOfType, customize: customize)
+            return introspect(selector: TargetViewSelector.siblingOfTypeOrAncestor, customize: customize)
         } else {
-            return introspect(selector: TargetViewSelector.ancestorOrSiblingContaining, customize: customize)
+            return introspect(selector: TargetViewSelector.siblingContainingOrAncestor, customize: customize)
         }
     }
     
@@ -157,7 +157,11 @@ extension View {
 
     /// Finds a `NSScrollView` from a `SwiftUI.ScrollView`, or `SwiftUI.ScrollView` child.
     public func introspectScrollView(customize: @escaping (NSScrollView) -> ()) -> some View {
-        return introspect(selector: TargetViewSelector.ancestorOrSiblingContaining, customize: customize)
+        if #available(macOS 11.0, *) {
+            return introspect(selector: TargetViewSelector.siblingOfTypeOrAncestor, customize: customize)
+        } else {
+            return introspect(selector: TargetViewSelector.siblingContainingOrAncestor, customize: customize)
+        }
     }
     
     /// Finds a `NSTextField` from a `SwiftUI.TextField`

IntrospectTests/AppKitTests.swift

@@ -55,8 +55,8 @@ private struct ListTestView: View {
 @available(macOS 10.15.0, *)
 private struct ScrollTestView: View {
     
-    let spy1: () -> Void
+    let spy1: (NSScrollView) -> Void
-    let spy2: () -> Void
+    let spy2: (NSScrollView) -> Void
     
     var body: some View {
         HStack {
@@ -64,13 +64,39 @@ private struct ScrollTestView: View {
                 Text("Item 1")
             }
             .introspectScrollView { scrollView in
-                self.spy1()
+                self.spy1(scrollView)
             }
+
             ScrollView {
                 Text("Item 1")
-                .introspectScrollView { scrollView in
+                    .introspectScrollView { scrollView in
-                    self.spy2()
+                        self.spy2(scrollView)
+                    }
+            }
+        }
+    }
+}
+
+@available(macOS 10.15.0, *)
+private struct NestedScrollTestView: View {
+
+    let spy1: (NSScrollView) -> Void
+    let spy2: (NSScrollView) -> Void
+
+    var body: some View {
+        HStack {
+            ScrollView {
+                Text("Item 1")
+
+                ScrollView {
+                    Text("Item 1")
                 }
+                .introspectScrollView { scrollView in
+                    self.spy2(scrollView)
+                }
+            }
+            .introspectScrollView { scrollView in
+                self.spy1(scrollView)
             }
         }
     }
@@ -175,18 +201,59 @@ class AppKitTests: XCTestCase {
         wait(for: [expectation1, expectation2, cellExpectation1, cellExpectation2], timeout: TestUtils.Constants.timeout)
     }
 
-    func testScrollView() {
+    func testScrollView() throws {
         
         let expectation1 = XCTestExpectation()
         let expectation2 = XCTestExpectation()
+
+        var scrollView1: NSScrollView?
+        var scrollView2: NSScrollView?
+
         let view = ScrollTestView(
-            spy1: { expectation1.fulfill() },
+            spy1: { scrollView in
-            spy2: { expectation2.fulfill() }
+                scrollView1 = scrollView
+                expectation1.fulfill() },
+            spy2: { scrollView in
+                scrollView2 = scrollView
+                expectation2.fulfill()
+            }
         )
         TestUtils.present(view: view)
         wait(for: [expectation1, expectation2], timeout: TestUtils.Constants.timeout)
+
+        let unwrappedScrollView1 = try XCTUnwrap(scrollView1)
+        let unwrappedScrollView2 = try XCTUnwrap(scrollView2)
+
+        XCTAssertNotEqual(unwrappedScrollView1, unwrappedScrollView2)
     }
-    
+
+    func testNestedScrollView() throws {
+
+        let expectation1 = XCTestExpectation()
+        let expectation2 = XCTestExpectation()
+
+        var scrollView1: NSScrollView?
+        var scrollView2: NSScrollView?
+
+        let view = NestedScrollTestView(
+            spy1: { scrollView in
+                scrollView1 = scrollView
+                expectation1.fulfill()
+            },
+            spy2: { scrollView in
+                scrollView2 = scrollView
+                expectation2.fulfill()
+            }
+        )
+        TestUtils.present(view: view)
+        wait(for: [expectation1, expectation2], timeout: TestUtils.Constants.timeout)
+
+        let unwrappedScrollView1 = try XCTUnwrap(scrollView1)
+        let unwrappedScrollView2 = try XCTUnwrap(scrollView2)
+
+        XCTAssertNotEqual(unwrappedScrollView1, unwrappedScrollView2)
+    }
+
     func testTextField() {
         
         let expectation = XCTestExpectation()

IntrospectTests/UIKitTests.swift

@@ -139,8 +139,8 @@ private struct ListTestView: View {
 @available(iOS 13.0, tvOS 13.0, macOS 10.15.0, *)
 private struct ScrollTestView: View {
     
-    let spy1: () -> Void
+    let spy1: (UIScrollView) -> Void
-    let spy2: () -> Void
+    let spy2: (UIScrollView) -> Void
     
     var body: some View {
         HStack {
@@ -148,18 +148,43 @@ private struct ScrollTestView: View {
                 Text("Item 1")
             }
             .introspectScrollView { scrollView in
-                self.spy1()
+                self.spy1(scrollView)
             }
             ScrollView {
                 Text("Item 1")
                 .introspectScrollView { scrollView in
-                    self.spy2()
+                    self.spy2(scrollView)
                 }
             }
         }
     }
 }
 
+@available(iOS 13.0, tvOS 13.0, macOS 10.15.0, *)
+private struct NestedScrollTestView: View {
+
+    let spy1: (UIScrollView) -> Void
+    let spy2: (UIScrollView) -> Void
+
+    var body: some View {
+        HStack {
+            ScrollView(showsIndicators: true) {
+                Text("Item 1")
+
+                ScrollView(showsIndicators: false) {
+                    Text("Item 1")
+                }
+                .introspectScrollView { scrollView in
+                    self.spy2(scrollView)
+                }
+            }
+            .introspectScrollView { scrollView in
+                self.spy1(scrollView)
+            }
+        }
+    }
+}
+
 @available(iOS 13.0, tvOS 13.0, macOS 10.15.0, *)
 private struct TextFieldTestView: View {
     let spy: () -> Void
@@ -316,18 +341,60 @@ class UIKitTests: XCTestCase {
         wait(for: [expectation1, expectation2, cellExpectation1, cellExpectation2], timeout: TestUtils.Constants.timeout)
     }
     
-    func testScrollView() {
+    func testScrollView() throws {
         
         let expectation1 = XCTestExpectation()
         let expectation2 = XCTestExpectation()
+
+        var scrollView1: UIScrollView?
+        var scrollView2: UIScrollView?
+
         let view = ScrollTestView(
-            spy1: { expectation1.fulfill() },
+            spy1: { scrollView in
-            spy2: { expectation2.fulfill() }
+                scrollView1 = scrollView
+                expectation1.fulfill()
+            },
+            spy2: { scrollView in
+                scrollView2 = scrollView
+                expectation2.fulfill()
+            }
         )
         TestUtils.present(view: view)
         wait(for: [expectation1, expectation2], timeout: TestUtils.Constants.timeout)
+
+        let unwrappedScrollView1 = try XCTUnwrap(scrollView1)
+        let unwrappedScrollView2 = try XCTUnwrap(scrollView2)
+
+        XCTAssertNotEqual(unwrappedScrollView1, unwrappedScrollView2)
     }
-    
+
+    func testNestedScrollView() throws {
+
+        let expectation1 = XCTestExpectation()
+        let expectation2 = XCTestExpectation()
+
+        var scrollView1: UIScrollView?
+        var scrollView2: UIScrollView?
+
+        let view = NestedScrollTestView(
+            spy1: { scrollView in
+                scrollView1 = scrollView
+                expectation1.fulfill()
+            },
+            spy2: { scrollView in
+                scrollView2 = scrollView
+                expectation2.fulfill()
+            }
+        )
+        TestUtils.present(view: view)
+        wait(for: [expectation1, expectation2], timeout: TestUtils.Constants.timeout)
+
+        let unwrappedScrollView1 = try XCTUnwrap(scrollView1)
+        let unwrappedScrollView2 = try XCTUnwrap(scrollView2)
+
+        XCTAssertNotEqual(unwrappedScrollView1, unwrappedScrollView2)
+    }
+
     func testTextField() {
         
         let expectation = XCTestExpectation()