Add CoordinatorProxyTests

Author: scenee

FloatingPanel.xcodeproj/project.pbxproj

@@ -87,6 +87,7 @@
 
 /* Begin PBXFileSystemSynchronizedRootGroup section */
 		5404FB662F3D70D600BCC99B /* UKit */ = {isa = PBXFileSystemSynchronizedRootGroup; explicitFileTypes = {}; explicitFolders = (); path = UKit; sourceTree = "<group>"; };
+		5404FB782F3D71C700BCC99B /* SwiftUI */ = {isa = PBXFileSystemSynchronizedRootGroup; explicitFileTypes = {}; explicitFolders = (); path = SwiftUI; sourceTree = "<group>"; };
 /* End PBXFileSystemSynchronizedRootGroup section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -157,6 +158,7 @@
 		545DB9CE2151169500CA77B8 /* Tests */ = {
 			isa = PBXGroup;
 			children = (
+				5404FB782F3D71C700BCC99B /* SwiftUI */,
 				5404FB662F3D70D600BCC99B /* UKit */,
 				545DB9D12151169500CA77B8 /* Info.plist */,
 			);
@@ -237,6 +239,7 @@
 			);
 			fileSystemSynchronizedGroups = (
 				5404FB662F3D70D600BCC99B /* UKit */,
+				5404FB782F3D71C700BCC99B /* SwiftUI */,
 			);
 			name = FloatingPanelTests;
 			productName = FloatingModalControllerTests;

Tests/SwiftUI/CoordinatorProxyTests.swift

@@ -0,0 +1,141 @@
+// Copyright 2018 the FloatingPanel authors. All rights reserved. MIT license.
+
+import SwiftUI
+import XCTest
+
+@testable import FloatingPanel
+
+@available(iOS 14, *)
+class CoordinatorProxyTests: XCTestCase {
+    override func setUp() {}
+    override func tearDown() {}
+
+    // MARK: - Test doubles
+
+    /// Records calls to `move(to:animated:completion:)` without performing real movement.
+    final class SpyFloatingPanelController: FloatingPanelController {
+        struct MoveCall {
+            let state: FloatingPanelState
+            let animated: Bool
+        }
+        fileprivate(set) var moveCalls: [MoveCall] = []
+
+        override func move(
+            to state: FloatingPanelState,
+            animated: Bool,
+            completion: (() -> Void)? = nil
+        ) {
+            moveCalls.append(MoveCall(state: state, animated: animated))
+            super.move(to: state, animated: animated, completion: completion)
+        }
+    }
+
+    /// A minimal `FloatingPanelCoordinator` that allows injecting a custom controller.
+    final class TestCoordinator: FloatingPanelCoordinator {
+        typealias Event = Void
+        let proxy: FloatingPanelProxy
+        let action: (Event) -> Void
+
+        init(action: @escaping (Event) -> Void) {
+            self.action = action
+            self.proxy = FloatingPanelProxy(controller: FloatingPanelController())
+        }
+
+        /// Designated initializer for tests — accepts a pre-made controller.
+        init(controller: FloatingPanelController) {
+            self.action = { _ in }
+            self.proxy = FloatingPanelProxy(controller: controller)
+        }
+
+        func setupFloatingPanel<Main: View, Content: View>(
+            mainHostingController: UIHostingController<Main>,
+            contentHostingController: UIHostingController<Content>
+        ) {
+            contentHostingController.view.backgroundColor = .clear
+            controller.set(contentViewController: contentHostingController)
+            controller.addPanel(toParent: mainHostingController, animated: false)
+        }
+
+        func onUpdate<Representable>(
+            context: UIViewControllerRepresentableContext<Representable>
+        ) where Representable: UIViewControllerRepresentable {}
+    }
+
+    // MARK: - Helpers
+
+    private func makeProxy(
+        spy: SpyFloatingPanelController
+    ) -> FloatingPanelCoordinatorProxy {
+        let coordinator = TestCoordinator(controller: spy)
+        spy.showForTest()
+        var state: FloatingPanelState? = spy.state
+        let binding = Binding<FloatingPanelState?>(
+            get: { state },
+            set: { state = $0 }
+        )
+        return FloatingPanelCoordinatorProxy(
+            coordinator: coordinator,
+            state: binding
+        )
+    }
+}
+
+// MARK: - Issue #680: update(state:) should skip move when state is unchanged
+
+/// Tests for `FloatingPanelCoordinatorProxy.update(state:)` — the internal bridge between
+/// SwiftUI state bindings and `FloatingPanelController`.
+@available(iOS 14, *)
+extension CoordinatorProxyTests {
+    /// During a drag gesture, a delegate callback can trigger a SwiftUI re-render which
+    /// calls `update(state:)` with the current state. The fix ensures this redundant call
+    /// does NOT invoke `controller.move(to:animated:)`, preserving the interactive transition.
+    func test_updateState_skipsMove_whenStateIsUnchanged() {
+        let spy = SpyFloatingPanelController()
+        let proxy = makeProxy(spy: spy)
+        XCTAssertEqual(spy.state, .half)
+
+        // Clear any move calls from setup
+        spy.moveCalls.removeAll()
+
+        // update(state:) with the SAME state must not trigger move(to:)
+        proxy.update(state: .half)
+
+        XCTAssertTrue(
+            spy.moveCalls.isEmpty,
+            "move(to:animated:) must not be called when the state is unchanged, "
+                + "but was called \(spy.moveCalls.count) time(s)"
+        )
+    }
+
+    func test_updateState_movesPanel_whenStateIsDifferent() {
+        let spy = SpyFloatingPanelController()
+        let proxy = makeProxy(spy: spy)
+        XCTAssertEqual(spy.state, .half)
+
+        spy.moveCalls.removeAll()
+
+        proxy.update(state: .full)
+
+        XCTAssertEqual(
+            spy.moveCalls.count, 1,
+            "move(to:animated:) should be called exactly once"
+        )
+        XCTAssertEqual(spy.moveCalls.first?.state, .full)
+        XCTAssertEqual(spy.moveCalls.first?.animated, false)
+    }
+
+    func test_updateState_doesNothing_whenStateIsNil() {
+        let spy = SpyFloatingPanelController()
+        let proxy = makeProxy(spy: spy)
+        XCTAssertEqual(spy.state, .half)
+
+        spy.moveCalls.removeAll()
+
+        proxy.update(state: nil)
+
+        XCTAssertTrue(
+            spy.moveCalls.isEmpty,
+            "move(to:animated:) must not be called when state is nil"
+        )
+    }
+}