FlutterUndoManagerPluginTest.mm

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// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
#import "flutter/shell/platform/darwin/ios/framework/Source/FlutterUndoManagerPlugin.h"
 
#import <OCMock/OCMock.h>
#import <XCTest/XCTest.h>
 
#import "flutter/shell/platform/darwin/common/framework/Headers/FlutterMacros.h"
 
FLUTTER_ASSERT_ARC
 
/// OCMock does not allow mocking both class and protocol. Use this to mock the methods used on
/// `UIView<UITextInput>*` in the plugin.
@interface TextInputViewTest : NSObject
 
@property(nonatomic, weak) id<UITextInputDelegate> inputDelegate;
@property(nonatomic, readonly) UITextInputAssistantItem* inputAssistantItem;
 
@end
 
@implementation TextInputViewTest
@end
 
@interface FakeFlutterUndoManagerDelegate : NSObject <FlutterUndoManagerDelegate>
 
@property(readonly) NSUInteger undoCount;
@property(readonly) NSUInteger redoCount;
@property(nonatomic, nullable) NSUndoManager* undoManager;
 
- (instancetype)initWithUndoManager:(NSUndoManager*)undoManager
                activeTextInputView:(TextInputViewTest*)activeTextInputView;
 
@end
 
@implementation FakeFlutterUndoManagerDelegate
 
@synthesize undoManager = _undoManager;
@synthesize activeTextInputView = _activeTextInputView;
 
- (instancetype)initWithUndoManager:(NSUndoManager*)undoManager
                activeTextInputView:(UIView<UITextInput>*)activeTextInputView {
  self = [super init];
  if (self) {
    _undoManager = undoManager;
    _activeTextInputView = activeTextInputView;
  }
  return self;
}
 
- (void)handleUndoWithDirection:(FlutterUndoRedoDirection)direction {
  if (direction == FlutterUndoRedoDirectionUndo) {
    _undoCount++;
  } else {
    _redoCount++;
  }
}
 
@end
 
@interface FlutterUndoManagerPluginTest : XCTestCase
@property(nonatomic) FakeFlutterUndoManagerDelegate* undoManagerDelegate;
@property(nonatomic) FlutterUndoManagerPlugin* undoManagerPlugin;
@property(nonatomic) TextInputViewTest* activeTextInputView;
@property(nonatomic) NSUndoManager* undoManager;
@end
 
@implementation FlutterUndoManagerPluginTest
 
- (void)setUp {
  [super setUp];
 
  self.undoManager = OCMClassMock([NSUndoManager class]);
  self.activeTextInputView = OCMClassMock([TextInputViewTest class]);
 
  self.undoManagerDelegate =
      [[FakeFlutterUndoManagerDelegate alloc] initWithUndoManager:self.undoManager
                                              activeTextInputView:self.activeTextInputView];
 
  self.undoManagerPlugin =
      [[FlutterUndoManagerPlugin alloc] initWithDelegate:self.undoManagerDelegate];
}
 
- (void)testSetUndoState {
  __block int registerUndoCount = 0;
  __block void (^undoHandler)(id target);
  OCMStub([self.undoManager registerUndoWithTarget:self.undoManagerPlugin handler:[OCMArg any]])
      .andDo(^(NSInvocation* invocation) {
        registerUndoCount++;
        __weak void (^handler)(id target);
        [invocation retainArguments];
        [invocation getArgument:&handler atIndex:3];
        undoHandler = handler;
      });
  __block int removeAllActionsCount = 0;
  OCMStub([self.undoManager removeAllActionsWithTarget:self.undoManagerPlugin])
      .andDo(^(NSInvocation* invocation) {
        removeAllActionsCount++;
      });
  __block int undoCount = 0;
  OCMStub([self.undoManager undo]).andDo(^(NSInvocation* invocation) {
    undoCount++;
    undoHandler(self.undoManagerPlugin);
  });
 
  // If canUndo and canRedo are false, only removeAllActionsWithTarget is called.
  FlutterMethodCall* setUndoStateCall =
      [FlutterMethodCall methodCallWithMethodName:@"UndoManager.setUndoState"
                                        arguments:@{@"canUndo" : @NO, @"canRedo" : @NO}];
  [self.undoManagerPlugin handleMethodCall:setUndoStateCall
                                    result:^(id _Nullable result){
                                    }];
  XCTAssertEqual(1, removeAllActionsCount);
  XCTAssertEqual(0, registerUndoCount);
 
  // If canUndo is true, an undo will be registered.
  setUndoStateCall =
      [FlutterMethodCall methodCallWithMethodName:@"UndoManager.setUndoState"
                                        arguments:@{@"canUndo" : @YES, @"canRedo" : @NO}];
  [self.undoManagerPlugin handleMethodCall:setUndoStateCall
                                    result:^(id _Nullable result){
                                    }];
  XCTAssertEqual(2, removeAllActionsCount);
  XCTAssertEqual(1, registerUndoCount);
 
  // Invoking the undo handler will invoke the handleUndo delegate method with "undo".
  undoHandler(self.undoManagerPlugin);
  XCTAssertEqual(1UL, self.undoManagerDelegate.undoCount);
  XCTAssertEqual(0UL, self.undoManagerDelegate.redoCount);
  XCTAssertEqual(2, registerUndoCount);
 
  // Invoking the redo handler will invoke the handleUndo delegate method with "redo".
  undoHandler(self.undoManagerPlugin);
  XCTAssertEqual(1UL, self.undoManagerDelegate.undoCount);
  XCTAssertEqual(1UL, self.undoManagerDelegate.redoCount);
  XCTAssertEqual(3, registerUndoCount);
 
  // If canRedo is true, an undo will be registered and undo will be called.
  setUndoStateCall =
      [FlutterMethodCall methodCallWithMethodName:@"UndoManager.setUndoState"
                                        arguments:@{@"canUndo" : @NO, @"canRedo" : @YES}];
  [self.undoManagerPlugin handleMethodCall:setUndoStateCall
                                    result:^(id _Nullable result){
                                    }];
  XCTAssertEqual(3, removeAllActionsCount);
  XCTAssertEqual(5, registerUndoCount);
  XCTAssertEqual(1, undoCount);
 
  // Invoking the redo handler will invoke the handleUndo delegate method with "redo".
  undoHandler(self.undoManagerPlugin);
  XCTAssertEqual(1UL, self.undoManagerDelegate.undoCount);
  XCTAssertEqual(2UL, self.undoManagerDelegate.redoCount);
}
 
- (void)testSetUndoStateDoesInteractWithInputDelegate {
  // Regression test for https://github.com/flutter/flutter/issues/133424
  FlutterMethodCall* setUndoStateCall =
      [FlutterMethodCall methodCallWithMethodName:@"UndoManager.setUndoState"
                                        arguments:@{@"canUndo" : @NO, @"canRedo" : @NO}];
  [self.undoManagerPlugin handleMethodCall:setUndoStateCall
                                    result:^(id _Nullable result){
                                    }];
 
  OCMVerify(never(), [self.activeTextInputView inputDelegate]);
}
 
- (void)testDeallocRemovesAllUndoManagerActions {
  __weak FlutterUndoManagerPlugin* weakUndoManagerPlugin;
  // Use a real undo manager.
  NSUndoManager* undoManager = [[NSUndoManager alloc] init];
  @autoreleasepool {
    id activeTextInputView = OCMClassMock([TextInputViewTest class]);
 
    FakeFlutterUndoManagerDelegate* undoManagerDelegate =
        [[FakeFlutterUndoManagerDelegate alloc] initWithUndoManager:undoManager
                                                activeTextInputView:activeTextInputView];
 
    FlutterUndoManagerPlugin* undoManagerPlugin =
        [[FlutterUndoManagerPlugin alloc] initWithDelegate:undoManagerDelegate];
    weakUndoManagerPlugin = undoManagerPlugin;
 
    FlutterMethodCall* setUndoStateCall =
        [FlutterMethodCall methodCallWithMethodName:@"UndoManager.setUndoState"
                                          arguments:@{@"canUndo" : @YES, @"canRedo" : @YES}];
    [undoManagerPlugin handleMethodCall:setUndoStateCall
                                 result:^(id _Nullable result){
                                 }];
    XCTAssertTrue(undoManager.canUndo);
    XCTAssertTrue(undoManager.canRedo);
    // Fake out the undoManager being nil, which happens when the FlutterViewController deallocs and
    // the undo manager can't be fetched from the FlutterEngine delegate.
    undoManagerDelegate.undoManager = nil;
  }
  XCTAssertNil(weakUndoManagerPlugin);
  // Regression test for https://github.com/flutter/flutter/issues/150408.
  // Undo manager undo and redo stack should be empty after the plugin deallocs.
  XCTAssertFalse(undoManager.canUndo);
  XCTAssertFalse(undoManager.canRedo);
}
 
@end