Bump mini supported Swift version to 5.9

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version:5.7
+// swift-tools-version:5.9
 
 import Foundation
 import PackageDescription
@@ -16,6 +16,7 @@ let supportedPlatforms: [Platform] = [
     .android,
     .windows,
     .wasi,
+    .visionOS,
 ]
 
 let cOpenCombineHelpersTarget: Target = .target(

Sources/OpenCombine/ObservableObject.swift

@@ -46,7 +46,6 @@ private protocol _ObservableObjectProperty {
     var objectWillChange: ObservableObjectPublisher? { get nonmutating set }
 }
 
-#if swift(>=5.1)
 extension Published: _ObservableObjectProperty {}
 
 extension ObservableObject where ObjectWillChangePublisher == ObservableObjectPublisher {
@@ -92,8 +91,6 @@ extension ObservableObject where ObjectWillChangePublisher == ObservableObjectPu
     }
 }
 
-#endif
-
 /// A publisher that publishes changes from observable objects.
 public final class ObservableObjectPublisher: Publisher {
 

Sources/OpenCombine/Published.swift

@@ -5,8 +5,6 @@
 //  Created by Евгений Богомолов on 01/09/2019.
 //
 
-#if swift(>=5.1)
-
 extension Publisher where Failure == Never {
 
     /// Republishes elements received from a publisher, by assigning them to a property
@@ -79,7 +77,6 @@ extension Publisher where Failure == Never {
 /// ### See Also
 ///
 /// - `Publisher.assign(to:)`
-@available(swift, introduced: 5.1)
 @propertyWrapper
 public struct Published<Value> {
 
@@ -218,9 +215,3 @@ public struct Published<Value> {
         // TODO: Benchmark and explore a possibility to use _modify
     }
 }
-#else
-
-@available(swift, introduced: 5.1)
-public typealias Published = Never
-
-#endif // swift(>=5.1)

Sources/OpenCombineFoundation/Helpers/Portability.swift

@@ -150,12 +150,7 @@ extension RunLoop.Mode {
         return CFRunLoopMode(rawValue as CFString)
 #else
         return rawValue.withCString {
-#if swift(>=5.3)
           let encoding = CFStringBuiltInEncodings.UTF8.rawValue
-#else
-          let encoding = CFStringEncoding(kCFStringEncodingUTF8)
-#endif // swift(>=5.3)
-
           return CFStringCreateWithCString(
               nil,
               $0,

Tests/OpenCombineTests/Helpers/CommonTests.swift

@@ -222,11 +222,7 @@ func fromNever<T>(_ resultType: T.Type) -> (Never) -> T {
     //
     // The second variant compiles with all Swift versions,
     // but produces a warning in Swift 5.1.
-#if swift(>=5.1)
     return { (_: Never) -> T in }
-#else
-    return { switch $0 {} }
-#endif
 }
 
 // swiftlint:enable generic_type_name

Tests/OpenCombineTests/ObservableObjectTests.swift

@@ -7,8 +7,6 @@
 
 import XCTest
 
-#if swift(>=5.1)
-
 #if OPENCOMBINE_COMPATIBILITY_TEST
 import Combine
 
@@ -420,5 +418,3 @@ private final class TestObject: ObservableObject {
         nonPublished = initialValue
     }
 }
-
-#endif

Tests/OpenCombineTests/PublishedTests.swift

@@ -7,8 +7,6 @@
 
 import XCTest
 
-#if swift(>=5.1)
-
 #if OPENCOMBINE_COMPATIBILITY_TEST
 import Combine
 
@@ -322,5 +320,3 @@ private final class TestObject: ObservableObject {
         _state = Published(initialValue: initialValue)
     }
 }
-
-#endif

Tests/OpenCombineTests/PublisherTests/MapKeyPathTests.swift

@@ -118,7 +118,6 @@ final class MapKeyPathTests: XCTestCase {
         }
     }
 
-    #if swift(>=5.8)
     #if Xcode
     func testMapKeyPathReflection() throws {
         try testReflection(parentInput: Int.self,
@@ -191,44 +190,6 @@ final class MapKeyPathTests: XCTestCase {
                            { $0.map(\.doubled, \.tripled, \.quadrupled) })
     }
     #endif
-    #else
-    // WASM Platform CI still use Swift 5.7
-    // which will get old KeyPath.description behavior
-    func testMapKeyPathReflection() throws {
-        try testReflection(parentInput: Int.self,
-                           parentFailure: Never.self,
-                           description: "ValueForKey",
-                           customMirror: expectedChildren(
-                               ("keyPath", .contains("KeyPath"))
-                           ),
-                           playgroundDescription: "ValueForKey",
-                           subscriberIsAlsoSubscription: false,
-                           { $0.map(\.doubled) })
-
-        try testReflection(parentInput: Int.self,
-                           parentFailure: Never.self,
-                           description: "ValueForKeys",
-                           customMirror: expectedChildren(
-                               ("keyPath0", .contains("KeyPath")),
-                               ("keyPath1", .contains("KeyPath"))
-                           ),
-                           playgroundDescription: "ValueForKeys",
-                           subscriberIsAlsoSubscription: false,
-                           { $0.map(\.doubled, \.tripled) })
-
-        try testReflection(parentInput: Int.self,
-                           parentFailure: Never.self,
-                           description: "ValueForKeys",
-                           customMirror: expectedChildren(
-                               ("keyPath0", .contains("KeyPath")),
-                               ("keyPath1", .contains("KeyPath")),
-                               ("keyPath2", .contains("KeyPath"))
-                           ),
-                           playgroundDescription: "ValueForKeys",
-                           subscriberIsAlsoSubscription: false,
-                           { $0.map(\.doubled, \.tripled, \.quadrupled) })
-    }
-    #endif
 
     func testMapKeyPathReceiveValueBeforeSubscription() {
         testReceiveValueBeforeSubscription(value: 0,