Merge remote-tracking branch 'origin/master' into anders/locks

Author: andersio

.swift-version

@@ -1 +1 @@
-4.1
+4.1.2

.travis.yml

@@ -1,5 +1,5 @@
 language: objective-c
-osx_image: xcode9.3
+osx_image: xcode9.4
 before_install: true
 install: true
 branches:
@@ -15,7 +15,7 @@ cache:
 
 jobs:
   include:
-    - osx_image: xcode9.3
+    - osx_image: xcode9.4
       script:
         - XCODE_SCHEME=ReactiveSwift-macOS
           XCODE_SDK=macosx
@@ -38,11 +38,14 @@ jobs:
           XCODE_DESTINATION="platform=watchOS Simulator,name=Apple Watch Series 3 - 38mm"
           script/build
     - script:
+        # To work around the lint error: "ERROR | swift: Specification `ReactiveSwift` specifies an inconsistent `swift_version` (`4.1`) compared to the one present in your `.swift-version` file (`4.1.2`). Please remove the `.swift-version` file which is now deprecated and only use the `swift_version` attribute within your podspec."
+        # `.swift-version` is for swiftenv, not for CocoaPods, so we can't remove the file as suggested.
+        - rm .swift-version
         - pod repo update --silent
         - pod lib lint ReactiveSwift.podspec
       env:
         - JOB=PODSPEC
-    - osx_image: xcode9.3
+    - osx_image: xcode9.4
       script:
         - swift --version
         - swift build

CHANGELOG.md

@@ -4,6 +4,19 @@
 
 # 4.0.0-rc.2
 
+*Please add new entries at the top.*
+
+1. [CocoaPods] CocoaPods 1.4.0 is the minimum required version. (#651, kudos to @ikesyo)
+1. `<~` bindings now works with optional left-hand-side operands. (#642, kudos to @andersio and @Ankit-Aggarwal)
+
+   ```swift
+   let nilTarget: BindingTarget<Int>? = nil
+
+   // This is now a valid binding. Previously required manual
+   // unwrapping in ReactiveSwift 3.x.
+   nilTarget <~ notifications.map { $0.count }
+   ```
+
 1. Support Swift 4.2 (Xcode 10) (#644, kudos to @ikesyo) 
 
 # 4.0.0-rc.1

Carthage/Checkouts/Nimble

@@ -20,4 +20,7 @@ Pod::Spec.new do |s|
   s.dependency 'Result', '~> 4.0'
 
   s.pod_target_xcconfig = {"OTHER_SWIFT_FLAGS[config=Release]" => "$(inherited) -suppress-warnings" }
+
+  s.cocoapods_version = ">= 1.4.0"
+  s.swift_version = "4.1"
 end

ReactiveSwift.podspec

@@ -149,3 +149,16 @@ public struct BindingTarget<Value>: BindingTargetProvider {
 		self.init(on: scheduler, lifetime: lifetime) { [weak object] in object?[keyPath: keyPath] = $0 }
 	}
 }
+
+extension Optional: BindingTargetProvider where Wrapped: BindingTargetProvider {
+	public typealias Value = Wrapped.Value
+
+	public var bindingTarget: BindingTarget<Wrapped.Value> {
+		switch self {
+		case let .some(provider):
+			return provider.bindingTarget
+		case .none:
+			return BindingTarget(lifetime: .empty, action: { _ in })
+		}
+	}
+}

Sources/UnidirectionalBinding.swift

@@ -21,8 +21,8 @@ class UnidirectionalBindingSpec: QuickSpec {
 			}
 
 			describe("closure binding target") {
-				var target: BindingTarget<Int>!
-				var optionalTarget: BindingTarget<Int?>!
+				var target: BindingTarget<Int>?
+				var optionalTarget: BindingTarget<Int?>?
 				var value: Int?
 
 				beforeEach {
@@ -33,40 +33,57 @@ class UnidirectionalBindingSpec: QuickSpec {
 
 				describe("non-optional target") {
 					it("should pass through the lifetime") {
-						expect(target.lifetime).to(beIdenticalTo(lifetime))
+						expect(target!.lifetime).to(beIdenticalTo(lifetime))
 					}
 
 					it("should trigger the supplied setter") {
 						expect(value).to(beNil())
 
-						target.action(1)
+						target!.action(1)
 						expect(value) == 1
 					}
 
 					it("should accept bindings from properties") {
 						expect(value).to(beNil())
 
 						let property = MutableProperty(1)
-						target <~ property
+						target! <~ property
 						expect(value) == 1
 
 						property.value = 2
 						expect(value) == 2
 					}
 				}
 
-				describe("optional target") {
+				describe("target of optional value") {
 					it("should pass through the lifetime") {
-						expect(optionalTarget.lifetime).to(beIdenticalTo(lifetime))
+						expect(optionalTarget!.lifetime).to(beIdenticalTo(lifetime))
 					}
 
 					it("should trigger the supplied setter") {
 						expect(value).to(beNil())
 
-						optionalTarget.action(1)
+						optionalTarget!.action(1)
 						expect(value) == 1
 					}
 
+					it("should accept bindings from properties") {
+						expect(value).to(beNil())
+
+						let property = MutableProperty(1)
+						optionalTarget! <~ property
+						expect(value) == 1
+
+						property.value = 2
+						expect(value) == 2
+					}
+				}
+
+				describe("optional LHS binding with non-nil LHS at runtime") {
+					it("should pass through the lifetime") {
+						expect(target.bindingTarget.lifetime).to(beIdenticalTo(lifetime))
+					}
+
 					it("should accept bindings from properties") {
 						expect(value).to(beNil())
 
@@ -78,6 +95,13 @@ class UnidirectionalBindingSpec: QuickSpec {
 						expect(value) == 2
 					}
 				}
+
+				describe("optional LHS binding with nil LHS at runtime") {
+					it("should pass through the empty lifetime") {
+						let nilTarget: BindingTarget<Int>? = nil
+						expect(nilTarget.bindingTarget.lifetime).to(beIdenticalTo(Lifetime.empty))
+					}
+				}
 			}
 
 			describe("key path binding target") {