Allow work factories with other return types than Observable

Changelog.md

@@ -3,6 +3,8 @@ Changelog
 
 Current master
 --------------
+- Add convenience initializer with work factories returning `PrimitiveSequence` or any other `ObservableConvertibleType` [#125](https://github.com/RxSwiftCommunity/Action/pull/125)
+- Introduce `CompletableAction`, a typealias for action that only completes without emitting any elements [#125](https://github.com/RxSwiftCommunity/Action/pull/125)
 
 3.4.0
 -----

Sources/Action/Action.swift

@@ -4,6 +4,8 @@ import RxCocoa
 
 /// Typealias for compatibility with UIButton's rx.action property.
 public typealias CocoaAction = Action<Void, Void>
+/// Typealias for actions with work factory returns `Completable`.
+public typealias CompletableAction<Input> = Action<Input, Never>
 
 /// Possible errors from invoking execute()
 public enum ActionError: Error {
@@ -52,10 +54,19 @@ public final class Action<Input, Element> {
 
     private let disposeBag = DisposeBag()
 
+    public convenience init<O: ObservableConvertibleType>(
+        enabledIf: Observable<Bool> = Observable.just(true),
+        workFactory: @escaping (Input) -> O
+    ) where O.E == Element {
+        self.init(enabledIf: enabledIf) {
+            workFactory($0).asObservable()
+        }
+    }
+
     public init(
         enabledIf: Observable<Bool> = Observable.just(true),
         workFactory: @escaping WorkFactory) {
-        
+
         self._enabledIf = enabledIf
         self.workFactory = workFactory
 
@@ -64,7 +75,7 @@ public final class Action<Input, Element> {
 
         let errorsSubject = PublishSubject<ActionError>()
         errors = errorsSubject.asObservable()
-        
+
         executionObservables = inputs
             .withLatestFrom(enabled) { input, enabled in (input, enabled) }
             .flatMap { input, enabled -> Observable<Observable<Element>> in
@@ -108,10 +119,10 @@ public final class Action<Input, Element> {
         }
 
 		let subject = ReplaySubject<Element>.createUnbounded()
-		
+
 		let work = executionObservables
 			.map { $0.catchError { throw ActionError.underlyingError($0) } }
-		
+
 		let error = errors
 			.map { Observable<Element>.error($0) }
 
@@ -120,7 +131,7 @@ public final class Action<Input, Element> {
 			.flatMap { $0 }
 			.subscribe(subject)
 			.disposed(by: disposeBag)
-		
+
 		return subject.asObservable()
     }
 }

Tests/ActionTests/ActionTests.swift

@@ -14,7 +14,35 @@ class ActionTests: QuickSpec {
 			scheduler = TestScheduler(initialClock: 0)
 			disposeBag = DisposeBag()
 		}
-
+
+        describe("completable action") {
+            var action: CompletableAction<String>!
+            beforeEach {
+                let work: Completable = Observable<Never>.empty().asCompletable()
+                action = CompletableAction {_ in work }
+                scheduler.scheduleAt(10) { action.inputs.onNext("a") }
+                scheduler.scheduleAt(20) { action.inputs.onNext("b") }
+            }
+            afterEach {
+                action = nil
+            }
+            it("inputs subject receives generated inputs") {
+                let inputs = scheduler.createObserver(String.self)
+                action.inputs.bind(to: inputs).disposed(by: disposeBag)
+                scheduler.start()
+                XCTAssertEqual(inputs.events, [
+                    next(10, "a"),
+                    next(20, "b"),
+                    ])
+            }
+            it("emits nothing on `elements`") {
+                let elements = scheduler.createObserver(Never.self)
+                action.elements.bind(to: elements).disposed(by: disposeBag)
+                scheduler.start()
+                XCTAssertEqual(elements.events.count, 0)
+            }
+        }
+
 		describe("action properties") {
 			var inputs: TestableObserver<String>!
 			var elements: TestableObserver<String>!