unused_closure_parameter: Remove unused closure parameters

RxCocoa/Traits/Driver/ControlEvent+Driver.swift

@@ -13,7 +13,7 @@ extension ControlEvent {
     ///
     /// `ControlEvent` already can't fail, so no special case needs to be handled.
     public func asDriver() -> Driver<E> {
-        return self.asDriver { (error) -> Driver<E> in
+        return self.asDriver { _ -> Driver<E> in
             #if DEBUG
                 rxFatalError("Somehow driver received error from a source that shouldn't fail.")
             #else

RxCocoa/Traits/Signal/ControlEvent+Signal.swift

@@ -13,7 +13,7 @@ extension ControlEvent {
     ///
     /// `ControlEvent` already can't fail, so no special case needs to be handled.
     public func asSignal() -> Signal<E> {
-        return self.asSignal { (error) -> Signal<E> in
+        return self.asSignal { _ -> Signal<E> in
             #if DEBUG
                 rxFatalError("Somehow signal received error from a source that shouldn't fail.")
             #else

RxCocoa/iOS/UIControl+Rx.swift

@@ -43,8 +43,7 @@ extension Reactive where Base: UIControl {
                     return Disposables.create()
                 }
 
-                let controlTarget = ControlTarget(control: control, controlEvents: controlEvents) {
-                    control in
+                let controlTarget = ControlTarget(control: control, controlEvents: controlEvents) { _ in
                     observer.on(.next(()))
                 }
 

RxCocoa/iOS/UISearchBar+Rx.swift

@@ -34,9 +34,7 @@ extension Reactive where Base: UISearchBar {
             let didEndEditing = (searchBar?.rx.delegate.methodInvoked(#selector(UISearchBarDelegate.searchBarTextDidEndEditing(_:))) ?? Observable.empty())
             
             return Observable.merge(textDidChange, didEndEditing)
-                    .map { a in
-                        return searchBar?.text ?? ""
-                    }
+                    .map { _ in searchBar?.text ?? "" }
                     .startWith(text)
         }
 

RxCocoa/macOS/NSControl+Rx.swift

@@ -29,7 +29,7 @@ extension Reactive where Base: NSControl {
                     return Disposables.create()
                 }
 
-                let observer = ControlTarget(control: control) { control in
+                let observer = ControlTarget(control: control) { _ in
                     observer.on(.next(()))
                 }
                 

RxSwift/Observables/Timer.swift

@@ -75,7 +75,7 @@ final private class TimerOneOffSink<O: ObserverType>: Sink<O> where O.E: RxAbstr
     }
     
     func run() -> Disposable {
-        return _parent._scheduler.scheduleRelative(self, dueTime: _parent._dueTime) { (`self`) -> Disposable in
+        return _parent._scheduler.scheduleRelative(self, dueTime: _parent._dueTime) { [unowned self] _ -> Disposable in
             self.forwardOn(.next(0))
             self.forwardOn(.completed)
             self.dispose()

Tests/RxCocoaTests/Driver+Test.swift

@@ -179,7 +179,7 @@ extension DriverTest {
 
     func testVariableAsDriver() {
         var hotObservable: Variable<Int>? = Variable(1)
-        let xs = Driver.zip(hotObservable!.asDriver(), Driver.of(0, 0)) { (optInt, int) in
+        let xs = Driver.zip(hotObservable!.asDriver(), Driver.of(0, 0)) { optInt, _ in
             return optInt
         }
 
@@ -228,7 +228,7 @@ extension DriverTest {
 
     func testAsDriver_onErrorRecover() {
         let hotObservable = BackgroundThreadPrimitiveHotObservable<Int>()
-        let xs = hotObservable.asDriver { e in
+        let xs = hotObservable.asDriver { _ in
             return Driver.empty()
         }
 

Tests/RxCocoaTests/NotificationCenterTests.swift

@@ -25,7 +25,7 @@ class NSNotificationCenterTests : RxTest {
         XCTAssertTrue(numberOfNotifications == 0)
         
         let subscription = notificationCenter.rx.notification(Notification.Name(rawValue: "testNotification"), object: nil)
-            .subscribe(onNext: { n in
+            .subscribe(onNext: { _ in
                 numberOfNotifications += 1
             })
 
@@ -61,7 +61,7 @@ class NSNotificationCenterTests : RxTest {
         XCTAssertTrue(numberOfNotifications == 0)
         
         let subscription = notificationCenter.rx.notification(Notification.Name(rawValue: "testNotification"), object: targetObject)
-            .subscribe(onNext: { n in
+            .subscribe(onNext: { _ in
                 numberOfNotifications += 1
             })
         

Tests/RxCocoaTests/Signal+Test.swift

@@ -225,7 +225,7 @@ extension SignalTests {
 
     func testAsSignal_onErrorRecover() {
         let hotObservable = BackgroundThreadPrimitiveHotObservable<Int>()
-        let xs = hotObservable.asSignal { e in
+        let xs = hotObservable.asSignal { _ in
             return Signal.empty()
         }
 

Tests/RxSwiftTests/Anomalies.swift

@@ -84,8 +84,7 @@ extension AnomaliesTest {
                         return Disposables.create()
                     }
                 })
-                .subscribe { (e) in
-                }
+                .subscribe()
         }
 
         for op in [
@@ -119,8 +118,7 @@ extension AnomaliesTest {
             }
 
         Observable.merge(foo, .just([42]))
-            .subscribe { (e) in
-            }
+            .subscribe()
             .disposed(by: disposeBag)
     }
 

Tests/RxSwiftTests/CurrentThreadSchedulerTest.swift

@@ -19,7 +19,7 @@ extension CurrentThreadSchedulerTest {
         XCTAssertTrue(CurrentThreadScheduler.isScheduleRequired)
 
         var executed = false
-        _ = CurrentThreadScheduler.instance.schedule(()) { s in
+        _ = CurrentThreadScheduler.instance.schedule(()) { _ in
             executed = true
             XCTAssertTrue(!CurrentThreadScheduler.isScheduleRequired)
             return Disposables.create()
@@ -33,9 +33,9 @@ extension CurrentThreadSchedulerTest {
         XCTAssertTrue(CurrentThreadScheduler.isScheduleRequired)
 
         var messages = [Int]()
-        _ = CurrentThreadScheduler.instance.schedule(()) { s in
+        _ = CurrentThreadScheduler.instance.schedule(()) { _ in
             messages.append(1)
-            _ = CurrentThreadScheduler.instance.schedule(()) { s in
+            _ = CurrentThreadScheduler.instance.schedule(()) { _ in
                 messages.append(3)
                 _ = CurrentThreadScheduler.instance.schedule(()) {
                     messages.append(5)
@@ -56,9 +56,9 @@ extension CurrentThreadSchedulerTest {
         XCTAssertTrue(CurrentThreadScheduler.isScheduleRequired)
 
         var messages = [Int]()
-        _ = CurrentThreadScheduler.instance.schedule(()) { s in
+        _ = CurrentThreadScheduler.instance.schedule(()) { _ in
             messages.append(1)
-            let disposable = CurrentThreadScheduler.instance.schedule(()) { s in
+            let disposable = CurrentThreadScheduler.instance.schedule(()) { _ in
                 messages.append(3)
                 let disposable = CurrentThreadScheduler.instance.schedule(()) {
                     messages.append(5)
@@ -80,9 +80,9 @@ extension CurrentThreadSchedulerTest {
         XCTAssertTrue(CurrentThreadScheduler.isScheduleRequired)
 
         var messages = [Int]()
-        _ = CurrentThreadScheduler.instance.schedule(()) { s in
+        _ = CurrentThreadScheduler.instance.schedule(()) { _ in
             messages.append(1)
-            let disposable = CurrentThreadScheduler.instance.schedule(()) { s in
+            let disposable = CurrentThreadScheduler.instance.schedule(()) { _ in
                 messages.append(3)
                 let disposable = CurrentThreadScheduler.instance.schedule(()) {
                     messages.append(5)

Tests/RxSwiftTests/MainSchedulerTests.swift

@@ -38,7 +38,7 @@ extension MainSchedulerTest {
         _ = MainScheduler.instance.schedule(()) { s in
             executedImmediately = true
             messages.append(1)
-            _ = MainScheduler.instance.schedule(()) { s in
+            _ = MainScheduler.instance.schedule(()) { _ in
                 messages.append(3)
                 _ = MainScheduler.instance.schedule(()) {
                     messages.append(5)
@@ -63,7 +63,7 @@ extension MainSchedulerTest {
         var messages = [Int]()
         _ = MainScheduler.instance.schedule(()) { s in
             messages.append(1)
-            let disposable = MainScheduler.instance.schedule(()) { s in
+            let disposable = MainScheduler.instance.schedule(()) { _ in
                 messages.append(3)
                 let disposable = MainScheduler.instance.schedule(()) {
                     messages.append(5)
@@ -87,7 +87,7 @@ extension MainSchedulerTest {
         var messages = [Int]()
         _ = MainScheduler.instance.schedule(()) { s in
             messages.append(1)
-            let disposable = MainScheduler.instance.schedule(()) { s in
+            let disposable = MainScheduler.instance.schedule(()) { _ in
                 messages.append(3)
                 let disposable = MainScheduler.instance.schedule(()) {
                     messages.append(5)

Tests/RxSwiftTests/Observable+CatchTests.swift

@@ -32,7 +32,7 @@ extension ObservableCatchTest {
         var handlerCalled: Int?
         
         let res = scheduler.start {
-            o1.catchError { e in
+            o1.catchError { _ in
                 handlerCalled = scheduler.clock
                 return o2.asObservable()
             }
@@ -69,7 +69,7 @@ extension ObservableCatchTest {
         var handlerCalled: Int?
         
         let res = scheduler.start {
-            o1.catchError { e in
+            o1.catchError { _ in
                 handlerCalled = scheduler.clock
                 throw testError1
             }

Tests/RxSwiftTests/Observable+CombineLatestTests.swift

@@ -835,7 +835,7 @@ extension ObservableCombineLatestTest {
             Observable.of(0, 1, 2)
         ) { $0 + $1 }
 
-        _ = observable.subscribe(onError: { n in
+        _ = observable.subscribe(onError: { _ in
             nEvents += 1
         })
         
@@ -1500,7 +1500,9 @@ extension ObservableCombineLatestTest {
             ])
         
         let res = scheduler.start {
-            Observable.combineLatest([e0, e1].map { $0.asObservable() }) { x throws -> Int in throw testError }
+            Observable
+                .combineLatest([e0, e1]
+                .map { $0.asObservable() }) { _ in throw testError }
         }
         
         XCTAssertEqual(res.events, [

Tests/RxSwiftTests/Observable+DistinctUntilChangedTests.swift

@@ -91,7 +91,7 @@ extension ObservableDistinctUntilChangedTest {
             .completed(250)
             ])
 
-        let res = scheduler.start { xs.distinctUntilChanged { l, r in true } }
+        let res = scheduler.start { xs.distinctUntilChanged { _, _ in true } }
 
         let correctMessages = Recorded.events(
             .next(210, 2),
@@ -118,7 +118,7 @@ extension ObservableDistinctUntilChangedTest {
             .completed(250)
             ])
 
-        let res = scheduler.start { xs.distinctUntilChanged({ l, r in false }) }
+        let res = scheduler.start { xs.distinctUntilChanged { _, _ in false } }
 
         let correctMessages = Recorded.events(
             .next(210, 2),

Tests/RxSwiftTests/Observable+DoOnTests.swift

@@ -142,7 +142,7 @@ extension ObservableDoOnTest {
 
         var i = 0
         var completedEvaluation = false
-        let res = scheduler.start { xs.do(onNext: { e in
+        let res = scheduler.start { xs.do(onNext: { _ in
                 i += 1
             }, onCompleted: {
                 completedEvaluation = true
@@ -224,7 +224,7 @@ extension ObservableDoOnTest {
         let res = scheduler.start { xs.do(onNext: { value in
                 i += 1
                 sum -= value
-            }, onError: { e in
+            }, onError: { _ in
                 sawError = true
             })
         }
@@ -263,7 +263,7 @@ extension ObservableDoOnTest {
 
         var numberOfTimesInvoked = 0
 
-        let res = scheduler.start { xs.do(onNext: { error in
+        let res = scheduler.start { xs.do(onNext: { _ in
                 numberOfTimesInvoked += 1
             })
         }
@@ -300,7 +300,7 @@ extension ObservableDoOnTest {
 
         var numberOfTimesInvoked = 0
 
-        let res = scheduler.start { xs.do(onNext: { error in
+        let res = scheduler.start { xs.do(onNext: { _ in
                 if numberOfTimesInvoked > 2 {
                     throw testError
                 }

Tests/RxSwiftTests/Observable+FilterTests.swift

@@ -103,7 +103,7 @@ extension ObservableFilterTest {
             ])
         
         let res = scheduler.start { () -> Observable<Int> in
-            return xs.filter { (num: Int) -> Bool in
+            return xs.filter { _ -> Bool in
                 invoked += 1
                 return true
             }
@@ -150,7 +150,7 @@ extension ObservableFilterTest {
             ])
         
         let res = scheduler.start { () -> Observable<Int> in
-            return xs.filter { (num: Int) -> Bool in
+            return xs.filter { _ -> Bool in
                 invoked += 1
                 return false
             }

Tests/RxSwiftTests/Observable+GenerateTests.swift

@@ -109,7 +109,7 @@ extension ObservableGenerateTest {
 
         func testGenerateReleasesResourcesOnError() {
             let testScheduler = TestScheduler(initialClock: 0)
-            _ = Observable<Int>.generate(initialState: 0, condition: { _ in false }, scheduler: testScheduler) { (x: Int) -> Int in
+            _ = Observable<Int>.generate(initialState: 0, condition: { _ in false }, scheduler: testScheduler) { _ -> Int in
                 throw testError
             }.subscribe()
             testScheduler.start()

Tests/RxSwiftTests/Observable+GroupByTests.swift

@@ -1118,7 +1118,7 @@ extension ObservableGroupByTest {
         }
 
         func testGroupByReleasesResourcesOnError2() {
-            _ = Observable<Int>.error(testError).groupBy { x -> Int in throw testError }.subscribe()
+            _ = Observable<Int>.error(testError).groupBy { _ -> Int in throw testError }.subscribe()
         }
     #endif
 }

Tests/RxSwiftTests/Observable+MergeTests.swift

@@ -23,7 +23,7 @@ extension ObservableMergeTest {
             Observable.of(0, 1, 2)
         ).merge()
         
-        _ = observable.subscribe(onNext: { n in
+        _ = observable.subscribe(onNext: { _ in
             nEvents += 1
         })
         
@@ -39,7 +39,7 @@ extension ObservableMergeTest {
             Observable.of(0, 1, 2)
         ).merge()
         
-        _ = observable.subscribe(onError: { n in
+        _ = observable.subscribe(onError: { _ in
             nEvents += 1
         })
         
@@ -53,7 +53,7 @@ extension ObservableMergeTest {
             Observable.error(testError)
         ).merge()
 
-        _ = observable.subscribe(onError: { n in
+        _ = observable.subscribe(onError: { _ in
             nEvents += 1
         })
         
@@ -91,7 +91,7 @@ extension ObservableMergeTest {
             Observable.of(0, 1, 2)
         ).merge(maxConcurrent: 1)
         
-        _ = observable.subscribe(onNext: { n in
+        _ = observable.subscribe(onNext: { _ in
             nEvents += 1
         })
         
@@ -121,7 +121,7 @@ extension ObservableMergeTest {
             Observable.error(testError)
         ).merge(maxConcurrent: 1)
 
-        _ = observable.subscribe(onError: { n in
+        _ = observable.subscribe(onError: { _ in
             nEvents += 1
         })
         

Tests/RxSwiftTests/Observable+MulticastTests.swift

@@ -807,7 +807,7 @@ extension ObservableMulticastTest {
         var nEvents = 0
 
         let observable = TestConnectableObservable(o: Observable.of(0, 1, 2), s: subject)
-        let d = observable.subscribe(onNext: { n in
+        let d = observable.subscribe(onNext: { _ in
             nEvents += 1
         })
 
@@ -826,7 +826,7 @@ extension ObservableMulticastTest {
         var nEvents = 0
 
         let observable = TestConnectableObservable(o: Observable.concat([Observable.of(0, 1, 2), Observable.error(testError)]), s: subject)
-        let d = observable.subscribe(onError: { n in
+        let d = observable.subscribe(onError: { _ in
             nEvents += 1
         })
 
@@ -845,7 +845,7 @@ extension ObservableMulticastTest {
         var nEvents = 0
 
         let observable = TestConnectableObservable(o: Observable.error(testError), s: subject)
-        let d = observable.subscribe(onError: { n in
+        let d = observable.subscribe(onError: { _ in
             nEvents += 1
         })
 
@@ -956,7 +956,7 @@ extension ObservableMulticastTest {
 
         let xs: Observable<Int> = Observable.deferred {
             count += 1
-            return Observable.create { obs in
+            return Observable.create { _ in
                 return Disposables.create {
                     disconnected = true
                 }

Tests/RxSwiftTests/Observable+ObserveOnTests.swift

@@ -47,7 +47,7 @@ extension ObservableObserveOnTest {
         let disposable = tests(scheduler)
         let expectation = self.expectation(description: "Wait for all tests to complete")
 
-        _ = scheduler.schedule(()) { s in
+        _ = scheduler.schedule(()) { _ in
             expectation.fulfill()
             return Disposables.create()
         }
@@ -81,7 +81,7 @@ extension ObservableObserveOnTest {
         runDispatchQueueSchedulerTests { scheduler in
             let observable = Observable.just(0)
                 .observeOn(scheduler)
-            return observable.subscribe(onNext: { n in
+            return observable.subscribe(onNext: { _ in
                 didExecute = true
                 XCTAssert(Thread.current !== unitTestsThread)
             })
@@ -131,7 +131,7 @@ extension ObservableObserveOnTest {
 
         runDispatchQueueSchedulerTests { scheduler in
             let observable: Observable<Int> = Observable.error(testError).observeOn(scheduler)
-            return observable.subscribe(onError: { n in
+            return observable.subscribe(onError: { _ in
                 nEvents += 1
             })
         }
@@ -158,7 +158,7 @@ extension ObservableObserveOnTest {
             let xs: Observable<Int> = Observable.never()
             return xs
                 .observeOn(scheduler)
-                .subscribe(onNext: { n in
+                .subscribe(onNext: { _ in
                     XCTAssert(false)
                 })
         }
@@ -498,7 +498,7 @@ class ObservableObserveOnTestConcurrentSchedulerTest: ObservableObserveOnTestBas
         let xs: Observable<Int> = Observable.never()
         let subscription = xs
             .observeOn(scheduler)
-            .subscribe(onNext: { n in
+            .subscribe(onNext: { _ in
                 XCTAssert(false)
             })
 

Tests/RxSwiftTests/Observable+RetryWhenTests.swift

@@ -45,7 +45,7 @@ extension ObservableRetryWhenTest {
             ])
 
         let res = scheduler.start(disposed: 300) {
-            xs.retryWhen { (errors: Observable<NSError>) in
+            xs.retryWhen { _ in
                 return empty
             }
         }
@@ -79,7 +79,7 @@ extension ObservableRetryWhenTest {
             ])
 
         let res = scheduler.start() {
-            xs.retryWhen { (errors: Observable<RetryWhenError>) in
+            xs.retryWhen { _ in
                 return never
             }
         }
@@ -116,7 +116,7 @@ extension ObservableRetryWhenTest {
             ])
 
         let res = scheduler.start() {
-            xs.retryWhen { (errors: Observable<RetryWhenError>) in
+            xs.retryWhen { _ in
                 return never
             }
         }
@@ -153,7 +153,7 @@ extension ObservableRetryWhenTest {
             ])
 
         let res = scheduler.start() {
-            xs.retryWhen { (errors: Observable<RetryWhenError>) in
+            xs.retryWhen { _ in
                 return empty
             }
         }
@@ -186,7 +186,7 @@ extension ObservableRetryWhenTest {
 
         let res = scheduler.start(disposed: 300) {
             xs.retryWhen { (errors: Observable<RetryWhenError>) in
-                return errors.scan(0) { (_a, e) in
+                return errors.scan(0) { (_a, _) in
                     var a = _a
                     a += 1
                     if a == 2 {
@@ -231,9 +231,9 @@ extension ObservableRetryWhenTest {
             ])
 
         let res = scheduler.start() {
-            xs.retryWhen({ (errors: Observable<RetryWhenError>) in
+            xs.retryWhen { _ in
                 return empty.asObservable()
-            })
+            }
         }
 
         let correct = Recorded.events(
@@ -262,7 +262,7 @@ extension ObservableRetryWhenTest {
 
         let res = scheduler.start(disposed: 300) {
             xs.retryWhen { (errors: Observable<RetryWhenError>) in
-                return errors.scan(0) { (a, e) in
+                return errors.scan(0) { a, _ in
                     return a + 1
                 }.takeWhile { (num: Int) -> Bool in
                     return num < 2
@@ -302,7 +302,7 @@ extension ObservableRetryWhenTest {
             ])
 
         let res = scheduler.start() {
-            xs.retryWhen { (errors: Observable<RetryWhenError>) in
+            xs.retryWhen { _ in
                 return never
             }
         }

Tests/RxSwiftTests/Observable+SkipUntilTests.swift

@@ -343,7 +343,7 @@ extension ObservableSkipUntilTest {
             .completed(250)
         ])
         
-        let r: Observable<Int> = Observable.create { o in
+        let r: Observable<Int> = Observable.create { _ in
             return Disposables.create {
                 isDisposed = true
             }

Tests/RxSwiftTests/Observable+SubscribeOnTests.swift

@@ -20,7 +20,7 @@ extension ObservableSubscribeOnTest {
         var scheduled = 0
         var disposed = 0
 
-        let xs: Observable<Int> = Observable.create { observer in
+        let xs: Observable<Int> = Observable.create { _ in
             scheduled = scheduler.clock
             return Disposables.create {
                 disposed = scheduler.clock

Tests/RxSwiftTests/Observable+UsingTests.swift

@@ -161,7 +161,7 @@ extension ObservableUsingTest {
             Observable.using({ () -> MockDisposable in
                 disposeInvoked += 1
                 throw testError
-            }, observableFactory: { d in
+            }, observableFactory: { _ in
                 createInvoked += 1
                 return Observable.never()
 
@@ -188,7 +188,7 @@ extension ObservableUsingTest {
                 disposeInvoked += 1
                 disposable = MockDisposable(scheduler: scheduler)
                 return disposable
-            }, observableFactory: { d in
+            }, observableFactory: { _ in
                 createInvoked += 1
                 throw testError
 

Tests/RxSwiftTests/ObserverTests.swift

@@ -124,7 +124,7 @@ extension ObserverTests {
     func testMapElementThrow() {
         let observer = PrimitiveMockObserver<Int>()
 
-        observer.mapObserver { (x: Int) -> Int in
+        observer.mapObserver { _ -> Int in
             throw testError
         }.on(.next(2))
 

Tests/RxSwiftTests/SchedulerTests.swift

@@ -141,14 +141,14 @@ extension OperationQueueSchedulerTests {
 
         var times = [String]()
 
-        _ = highPriority.schedule(Int.self) { (value) -> Disposable in
+        _ = highPriority.schedule(Int.self) { _ -> Disposable in
             Thread.sleep(forTimeInterval: 0.4)
             times.append("HIGH")
 
             return Disposables.create()
             }
 
-        _ = lowPriority.schedule(Int.self) { (value) -> Disposable in
+        _ = lowPriority.schedule(Int.self) { _ -> Disposable in
             Thread.sleep(forTimeInterval: 1)
             times.append("LOW")
 
@@ -157,7 +157,7 @@ extension OperationQueueSchedulerTests {
             return Disposables.create()
             }
 
-        _ = highPriority.schedule(Int.self) { (value) -> Disposable in
+        _ = highPriority.schedule(Int.self) { _ -> Disposable in
             Thread.sleep(forTimeInterval: 0.2)
             times.append("HIGH")