Fixes observable sequence completion in case of empty arrays for combineLatest and zip. ReactiveX#1205

kzaher · kzaher · commit 9e723c8f78fa · 2017-04-30T00:32:08.000+02:00
diff --git a/RxSwift/Observables/CombineLatest+Collection.swift b/RxSwift/Observables/CombineLatest+Collection.swift
@@ -127,6 +127,10 @@ final fileprivate class CombineLatestCollectionTypeSink<C: Collection, O: Observ
             
             j += 1
         }
+
+        if _parent._sources.isEmpty {
+            self.forwardOn(.completed)
+        }
         
         return Disposables.create(_subscriptions)
     }
diff --git a/RxSwift/Observables/Zip+Collection.swift b/RxSwift/Observables/Zip+Collection.swift
@@ -139,6 +139,10 @@ final fileprivate class ZipCollectionTypeSink<C: Collection, O: ObserverType>
             _subscriptions[j].setDisposable(disposable)
             j += 1
         }
+
+        if _parent.sources.isEmpty {
+            self.forwardOn(.completed)
+        }
         
         return Disposables.create(_subscriptions)
     }
diff --git a/Sources/AllTestz/main.swift b/Sources/AllTestz/main.swift
@@ -725,6 +725,7 @@ final class ObservableZipTest_ : ObservableZipTest, RxTestCase {
     ("testZip_RightCompletesFirst", ObservableZipTest.testZip_RightCompletesFirst),
     ("testZip_LeftTriggersSelectorError", ObservableZipTest.testZip_LeftTriggersSelectorError),
     ("testZip_RightTriggersSelectorError", ObservableZipTest.testZip_RightTriggersSelectorError),
+    ("testZip_NAry_emptyArray", ObservableZipTest.testZip_NAry_emptyArray),
     ("testZip_NAry_symmetric", ObservableZipTest.testZip_NAry_symmetric),
     ("testZip_NAry_asymmetric", ObservableZipTest.testZip_NAry_asymmetric),
     ("testZip_NAry_error", ObservableZipTest.testZip_NAry_error),
@@ -1294,6 +1295,7 @@ final class ObservableCombineLatestTest_ : ObservableCombineLatestTest, RxTestCa
     ("testCombineLatest_DeadlockErrorAfterN", ObservableCombineLatestTest.testCombineLatest_DeadlockErrorAfterN),
     ("testCombineLatest_DeadlockErrorImmediatelly", ObservableCombineLatestTest.testCombineLatest_DeadlockErrorImmediatelly),
     ("testReplay_DeadlockEmpty", ObservableCombineLatestTest.testReplay_DeadlockEmpty),
+    ("testCombineLatest_emptyArrayN", ObservableCombineLatestTest.testCombineLatest_emptyArrayN),
     ("testCombineLatest_NeverN", ObservableCombineLatestTest.testCombineLatest_NeverN),
     ("testCombineLatest_NeverEmptyN", ObservableCombineLatestTest.testCombineLatest_NeverEmptyN),
     ("testCombineLatest_EmptyNeverN", ObservableCombineLatestTest.testCombineLatest_EmptyNeverN),
diff --git a/Tests/RxSwiftTests/Observable+CombineLatestTests.swift b/Tests/RxSwiftTests/Observable+CombineLatestTests.swift
@@ -886,6 +886,27 @@ extension ObservableCombineLatestTest {
 
 
 extension ObservableCombineLatestTest {
+    func testCombineLatest_emptyArrayN() {
+        let factories: [() -> Observable<Int>] =
+            [
+                {
+                    Observable<Int>.combineLatest(([] as [Observable<Int>]).map { $0.asObservable() }).map { $0.reduce(0, +) }
+                },
+                {
+                    Observable.combineLatest(([] as [Observable<Int>]).map { $0.asObservable() }) { $0.reduce(0, +) }
+                },
+            ]
+        for factory in factories {
+            let scheduler = TestScheduler(initialClock: 0)
+
+            let res = scheduler.start {
+                factory()
+            }
+
+            XCTAssertEqual(res.events, [completed(200, Int.self)])
+        }
+    }
+    
     func testCombineLatest_NeverN() {
         let factories: [(TestableObservable<Int>, TestableObservable<Int>, TestableObservable<Int>) -> Observable<Int>] =
             [
diff --git a/Tests/RxSwiftTests/Observable+ZipTests.swift b/Tests/RxSwiftTests/Observable+ZipTests.swift
@@ -606,6 +606,26 @@ extension ObservableZipTest {
 }
 
 extension ObservableZipTest {
+    func testZip_NAry_emptyArray() {
+        let factories: [() -> Observable<EquatableArray<Int>>] =
+            [
+                { Observable.zip(([] as [Observable<Int>]).map { $0.asObservable() }) { EquatableArray($0) } },
+                { Observable.zip(([] as [Observable<Int>]).map { $0.asObservable() }).map { EquatableArray($0) } },
+                ]
+
+        for factory in factories {
+            let scheduler = TestScheduler(initialClock: 0)
+
+            let res = scheduler.start {
+                factory()
+            }
+
+            XCTAssertEqual(res.events, [
+                completed(200)
+                ])
+        }
+    }
+    
     func testZip_NAry_symmetric() {
         let factories: [(TestableObservable<Int>, TestableObservable<Int>, TestableObservable<Int>) -> Observable<EquatableArray<Int>>] =
             [

Original file line number	Diff line number	Diff line change
`@@ -127,6 +127,10 @@ final fileprivate class CombineLatestCollectionTypeSink<C: Collection, O: Observ`
`127`	`127`
`128`	`128`	`j += 1`
`129`	`129`	`}`
	`130`	`+`
	`131`	`+ if _parent._sources.isEmpty {`
	`132`	`+ self.forwardOn(.completed)`
	`133`	`+ }`
`130`	`134`
`131`	`135`	`return Disposables.create(_subscriptions)`
`132`	`136`	`}`
Original file line number	Diff line number	Diff line change
`@@ -139,6 +139,10 @@ final fileprivate class ZipCollectionTypeSink<C: Collection, O: ObserverType>`
`139`	`139`	`_subscriptions[j].setDisposable(disposable)`
`140`	`140`	`j += 1`
`141`	`141`	`}`
	`142`	`+`
	`143`	`+ if _parent.sources.isEmpty {`
	`144`	`+ self.forwardOn(.completed)`
	`145`	`+ }`
`142`	`146`
`143`	`147`	`return Disposables.create(_subscriptions)`
`144`	`148`	`}`