Add NSButton Introspection (#85)

CHANGELOG.md

@@ -3,6 +3,7 @@ Changelog
 
 ## master
 
+- Added `.introspectButton()` on macOS
 - Fix UITextField with cornerRadius
 - Added `.introspectTabView()` on macOS
 

Introspect/ViewExtensions.swift

@@ -198,5 +198,10 @@ extension View {
     public func introspectTabView(customize: @escaping (NSTabView) -> ()) -> some View {
         return introspect(selector: TargetViewSelector.siblingContaining, customize: customize)
     }
+    
+    /// Finds a `NSButton` from a `SwiftUI.Button`
+    public func introspectButton(customize: @escaping (NSButton) -> ()) -> some View {
+        return introspect(selector: TargetViewSelector.siblingContaining, customize: customize)
+    }
 }
 #endif

IntrospectTests/AppKitTests.swift

@@ -203,6 +203,17 @@ private struct TabViewTestView: View {
     }
 }
 
+@available(macOS 10.15.0, *)
+private struct ButtonTestView: View {
+    let spy: () -> Void
+    var body: some View {
+        Button("Test", action: {})
+        .introspectButton { button in
+            self.spy()
+        }
+    }
+}
+
 @available(macOS 10.15.0, *)
 class AppKitTests: XCTestCase {
     
@@ -346,5 +357,15 @@ class AppKitTests: XCTestCase {
         TestUtils.present(view: view)
         wait(for: [expectation], timeout: TestUtils.Constants.timeout)
     }
+    
+    func testButton() {
+        
+        let expectation = XCTestExpectation()
+        let view = ButtonTestView(spy: {
+            expectation.fulfill()
+        })
+        TestUtils.present(view: view)
+        wait(for: [expectation], timeout: TestUtils.Constants.timeout)
+    }
 }
 #endif