diff --git a/.swift-version b/.swift-version new file mode 100644 index 0000000..9f55b2c --- /dev/null +++ b/.swift-version @@ -0,0 +1 @@ +3.0 diff --git a/CHANGELOG.md b/CHANGELOG.md index 6b71bdf..d088ae2 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -1,3 +1,56 @@ +# 4.0.0 + +This major release improves the general usage of the observable pattern by removing the +auto-unsubscription behavior from the Subscription type on deallocation. + +```swift +// Pre-4.0 usage required that you held on to the Subscription instance in order to continue +// receiving values +let subscription = observable.subscribe { value in + print(value) +} + +// 4.0 allows you to subscribe to streams without holding on to the Subscription instance. +observable.subscribe { value in + print(value) +} +``` + +## Breaking changes + +• Subscriptions no longer unsubscribe automatically upon deallocation. + +This means that you no longer need to hold on to a Subscription in order to continue receiving +values from a subscribed stream. + +If you were previously depending on this behavior then you must now ensure that you explicitly +unsubscribe from subscriptions. + +## Source changes + +* [[breaking] Remove automatic unsubscription from the Subscription object.](https://github.com/material-motion/indefinite-observable-swift/commit/8f5b89cf26bb4e0d26eca254419741278a290ec8) (Jeff Verkoeyen) + +## API changes + +Auto-generated by running: + + apidiff origin/stable release-candidate swift IndefiniteObservable.xcworkspace IndefiniteObservable + +## Subscription + +## IndefiniteObservable + +*modified* method: `subscribe(observer:)` in `IndefiniteObservable` + +| Type of change: | key.attributes | +|---|---| +| From: | `( { "key.attribute" = "source.decl.attribute.final"; } )` | +| To: | `( { "key.attribute" = "source.decl.attribute.final"; }, { "key.attribute" = "source.decl.attribute.discardableResult"; } )` | + +## Non-source changes + +* [Update README with new documentation for subscriptions.](https://github.com/material-motion/indefinite-observable-swift/commit/a492076d65aa9540737ac845fb1380c46cf53a9b) (Jeff Verkoeyen) + # 3.1.0 ## New features diff --git a/IndefiniteObservable.podspec b/IndefiniteObservable.podspec index a18e15c..e85ef57 100644 --- a/IndefiniteObservable.podspec +++ b/IndefiniteObservable.podspec @@ -1,7 +1,7 @@ Pod::Spec.new do |s| s.name = "IndefiniteObservable" s.summary = "IndefiniteObservable is a minimal implementation of Observable with no concept of completion or failure." - s.version = "3.1.0" + s.version = "4.0.0" s.authors = "The Material Motion Authors" s.license = "Apache 2.0" s.homepage = "https://github.com/material-motion/indefinite-observable-swift" diff --git a/Podfile.lock b/Podfile.lock index e76cbb9..6eac55d 100644 --- a/Podfile.lock +++ b/Podfile.lock @@ -1,8 +1,8 @@ PODS: - CatalogByConvention (2.0.0) - - IndefiniteObservable/examples (3.1.0): + - IndefiniteObservable/examples (4.0.0): - IndefiniteObservable/lib - - IndefiniteObservable/lib (3.1.0) + - IndefiniteObservable/lib (4.0.0) DEPENDENCIES: - CatalogByConvention @@ -15,8 +15,8 @@ EXTERNAL SOURCES: SPEC CHECKSUMS: CatalogByConvention: be55c2263132e4f9f59299ac8a528ee8715b3275 - IndefiniteObservable: 8dd88933eb00b0186cdcc665692beba53da34f44 + IndefiniteObservable: 0e948393173ea7dc68a9f439530559aa84d96d4c PODFILE CHECKSUM: 3e4cdba95901e07a289159f0c5a8b830ecb1a5c8 -COCOAPODS: 1.1.1 +COCOAPODS: 1.2.0 diff --git a/README.md b/README.md index 180db14..a5ab652 100644 --- a/README.md +++ b/README.md @@ -112,20 +112,22 @@ let observable = ValueObservable<<#ValueType#>> { observer in ## How to subscribe to a stream -Streams are kept in memory by their subscriptions. - ```swift -let subscription = observable.subscribe { value in +observable.subscribe { value in print(value) } ``` ## How to unsubscribe from a stream -Unsubscribe from a stream to allow the stream to be released. The stream can be deallocated once all -of its subscriptions have unsubscribed. +Unsubscribing will invoke the observable's disconnect method. To unsubscribe, you must retain a +reference to the subscription instance returned by subscribe. ```swift +let subscription = observable.subscribe { value in + print(value) +} + subscription.unsubscribe() ``` diff --git a/src/IndefiniteObservable.swift b/src/IndefiniteObservable.swift index 04e159d..af45fd3 100644 --- a/src/IndefiniteObservable.swift +++ b/src/IndefiniteObservable.swift @@ -57,14 +57,18 @@ open class IndefiniteObservable { /** Subscribes to the IndefiniteObservable. - The returned subscription will hold a strong reference to the IndefiniteObservable chain. The - reference can be released by calling unsubscribe on the returned subscription. The Subscription - is type-erased, making it possible to keep a collection of Subscription objects for as long as - you need the associated streams alive. + The returned subscription will hold a strong reference to the disconnect chain. The reference can + be released by calling unsubscribe on the returned subscription. The Subscription is type-erased, + making it possible to keep a collection of Subscription objects for as long as you need the + associated streams alive. + + If you do not keep the returned subscription then the disconnect calls will never be invoked for + this observer. - Parameter next: A block that will be executed when new values are sent from upstream. - Returns: A subscription. */ + @discardableResult public final func subscribe(observer: O) -> Subscription { return Subscription(connect(observer)) } @@ -82,10 +86,6 @@ public typealias Disconnect = () -> Void /** A Subscription is returned by IndefiniteObservable.subscribe. */ public final class Subscription { - deinit { - unsubscribe() - } - public init(_ disconnect: @escaping () -> Void) { self.disconnect = disconnect } diff --git a/tests/unit/MemoryLeakTests.swift b/tests/unit/MemoryLeakTests.swift index fdc0291..59bec13 100644 --- a/tests/unit/MemoryLeakTests.swift +++ b/tests/unit/MemoryLeakTests.swift @@ -63,7 +63,7 @@ class MemoryLeakTests: XCTestCase { weak var weakObservable = observable autoreleasepool { - let _ = observable!.subscribe { + observable!.subscribe { let _ = $0 } // Remove our only strong reference. @@ -83,7 +83,7 @@ class MemoryLeakTests: XCTestCase { weak var weakObservable = observable autoreleasepool { - let _ = observable!.map { value in + observable!.map { value in return value * value }.subscribe { let _ = $0 @@ -97,7 +97,7 @@ class MemoryLeakTests: XCTestCase { XCTAssertNil(weakObservable) } - func testUnsubscribedObservableWithOperatorIsDeallocated() { + func testObservableWithOperatorIsDeallocated() { weak var weakObservable: ValueObservable? autoreleasepool { let observable: ValueObservable? = ValueObservable { observer in @@ -106,13 +106,11 @@ class MemoryLeakTests: XCTestCase { } weakObservable = observable - let subscription = observable!.map { value in + observable!.map { value in return value * value - }.subscribe { - let _ = $0 - } - // Remove our only strong reference. - subscription.unsubscribe() + }.subscribe { + let _ = $0 + } } // If this fails it means there's a retain cycle. Place a breakpoint here and use the Debug @@ -122,7 +120,6 @@ class MemoryLeakTests: XCTestCase { func testSubscriptionDoesNotKeepObservableInMemory() { weak var weakObservable: ValueObservable? - var subscription: Subscription? autoreleasepool { let value = 10 @@ -132,11 +129,34 @@ class MemoryLeakTests: XCTestCase { } weakObservable = observable - subscription = observable.subscribe { _ in } + observable.subscribe { _ in } } XCTAssertNil(weakObservable) + } + + func testSubscriptionDoesNotKeepObserverInMemory() { + weak var weakObserver: ValueObserver? + + var didDisconnect = false + var didSetObserver = false + + autoreleasepool { + let value = 10 + let observable = ValueObservable { observer in + weakObserver = observer + didSetObserver = true + observer.next(value) + return { + didDisconnect = true + } + } + + observable.subscribe { _ in } + } - subscription?.unsubscribe() + XCTAssertNil(weakObserver) + XCTAssertTrue(didSetObserver) + XCTAssertFalse(didDisconnect) } } diff --git a/tests/unit/ObservableTests.swift b/tests/unit/ObservableTests.swift index a976076..88e2856 100644 --- a/tests/unit/ObservableTests.swift +++ b/tests/unit/ObservableTests.swift @@ -29,7 +29,7 @@ class ObservableTests: XCTestCase { } let wasReceived = expectation(description: "Value was received") - let _ = observable.subscribe { + observable.subscribe { if $0 == value { wasReceived.fulfill() } @@ -38,7 +38,7 @@ class ObservableTests: XCTestCase { waitForExpectations(timeout: 0) } - func testUnsubscribesOnDeallocation() { + func testDoesNotUnsubscribeOnDeallocation() { var didUnsubscribe = false autoreleasepool { @@ -48,10 +48,10 @@ class ObservableTests: XCTestCase { } } - let _ = observable.subscribe { _ in } + observable.subscribe { _ in } } - XCTAssertTrue(didUnsubscribe) + XCTAssertFalse(didUnsubscribe) } func testUnsubscribesOnUnsubscribe() { @@ -78,14 +78,14 @@ class ObservableTests: XCTestCase { } let wasReceived = expectation(description: "Value was received") - let _ = observable.subscribe { + observable.subscribe { if $0 == value { wasReceived.fulfill() } } let wasReceived2 = expectation(description: "Value was received") - let _ = observable.subscribe { + observable.subscribe { if $0 == value { wasReceived2.fulfill() } @@ -103,23 +103,20 @@ class ObservableTests: XCTestCase { } let wasReceived = expectation(description: "Value was received") - let subscription1 = observable.subscribe { + observable.subscribe { if $0 == value { wasReceived.fulfill() } } let wasReceived2 = expectation(description: "Value was received") - let subscription2 = observable.subscribe { + observable.subscribe { if $0 == value { wasReceived2.fulfill() } } waitForExpectations(timeout: 0) - - subscription1.unsubscribe() - subscription2.unsubscribe() } func testMappingValues() { @@ -130,7 +127,7 @@ class ObservableTests: XCTestCase { } let wasReceived = expectation(description: "Value was received") - let _ = observable.map { $0 * $0 }.subscribe { + observable.map { $0 * $0 }.subscribe { if $0 == value * value { wasReceived.fulfill() } @@ -147,7 +144,7 @@ class ObservableTests: XCTestCase { } let wasReceived = expectation(description: "Value was received") - let _ = observable.map { $0.y }.subscribe { + observable.map { $0.y }.subscribe { if $0 == value.y { wasReceived.fulfill() } @@ -165,7 +162,7 @@ class ObservableTests: XCTestCase { } var filteredValues: [CGPoint] = [] - let _ = observable.filter { (state, _) in state == true }.map { $0.1 }.subscribe { + observable.filter { (state, _) in state == true }.map { $0.1 }.subscribe { filteredValues.append($0) } @@ -202,11 +199,11 @@ class ObservableTests: XCTestCase { } var valuesObserved: [Int] = [] - let subscription1 = observable.subscribe { + observable.subscribe { valuesObserved.append($0) } - let subscription2 = observable.subscribe { + observable.subscribe { valuesObserved.append($0 * 2) } @@ -215,9 +212,6 @@ class ObservableTests: XCTestCase { generator.emit(2) XCTAssertEqual(valuesObserved, [5, 10, 10, 20, 2, 4]) - - subscription1.unsubscribe() - subscription2.unsubscribe() } func testGeneratedValuesAreNotReceivedAfterUnsubscription() { @@ -231,22 +225,20 @@ class ObservableTests: XCTestCase { } var valuesObserved: [Int] = [] - let subscription1 = observable.subscribe { + observable.subscribe { valuesObserved.append($0) } - let subscription2 = observable.subscribe { + let subscription = observable.subscribe { valuesObserved.append($0 * 2) } generator.emit(5) generator.emit(10) - subscription2.unsubscribe() + subscription.unsubscribe() generator.emit(2) XCTAssertEqual(valuesObserved, [5, 10, 10, 20, 2]) - - subscription1.unsubscribe() } func testGeneratedValuesAreNotReceivedAfterUnsubscriptionOrder2() { @@ -263,22 +255,20 @@ class ObservableTests: XCTestCase { weakObservable = observable var valuesObserved: [Int] = [] - let subscription1 = observable.subscribe { + let subscription = observable.subscribe { valuesObserved.append($0) } - let subscription2 = observable.map { $0 * 2 }.subscribe { + observable.map { $0 * 2 }.subscribe { valuesObserved.append($0) } generator.emit(5) generator.emit(10) - subscription1.unsubscribe() + subscription.unsubscribe() generator.emit(2) XCTAssertEqual(valuesObserved, [5, 10, 10, 20, 4]) - - subscription2.unsubscribe() } // If this fails it means there's a retain cycle. Place a breakpoint here and use the Debug diff --git a/tests/unit/SimpleOperators.swift b/tests/unit/SimpleOperators.swift index 040860c..43f0160 100644 --- a/tests/unit/SimpleOperators.swift +++ b/tests/unit/SimpleOperators.swift @@ -30,6 +30,7 @@ public final class ValueObserver: Observer { } public class ValueObservable: IndefiniteObservable> { + @discardableResult public final func subscribe(_ next: @escaping (T) -> Void) -> Subscription { return super.subscribe(observer: ValueObserver(next)) }