Add SwiftPM support on macOS

.Package.test.swift

@@ -2,18 +2,38 @@ import PackageDescription
 
 let package = Package(
     name: "Quick",
+    targets: {
+#if _runtime(_ObjC)
+        return [
+            Target(name: "QuickSpecBase"),
+            Target(name: "Quick", dependencies: [ "QuickSpecBase" ]),
+            Target(name: "QuickTests", dependencies: [ "Quick" ]),
+        ]
+#else
+        return [
+            Target(name: "Quick"),
+            Target(name: "QuickTests", dependencies: [ "Quick" ]),
+        ]
+#endif
+    }(),
     // TODO: Once the `test` command has been implemented in the Swift Package Manager, this should be changed to
     // be `testDependencies:` instead. For now it has to be done like this for the library to get linked with the test targets.
     // See: https://github.com/apple/swift-evolution/blob/master/proposals/0019-package-manager-testing.md
     dependencies: [
-        .Package(url: "https://github.com/Quick/Nimble", majorVersion: 5)
+        .Package(url: "https://github.com/Quick/Nimble", majorVersion: 6)
     ],
-    exclude: [
-      "Sources/QuickObjectiveC",
-      "Tests/QuickTests/QuickAfterSuiteTests/AfterSuiteTests+ObjC.m",
-      "Tests/QuickTests/QuickFocusedTests/FocusedTests+ObjC.m",
-      "Tests/QuickTests/QuickTests/FunctionalTests/ObjC",
-      "Tests/QuickTests/QuickTests/Helpers",
-      "Tests/QuickTests/QuickTests/QuickConfigurationTests.m",
-    ]
+    exclude: {
+        var excludes = [
+            "Sources/QuickObjectiveC",
+            "Tests/QuickTests/QuickAfterSuiteTests/AfterSuiteTests+ObjC.m",
+            "Tests/QuickTests/QuickFocusedTests/FocusedTests+ObjC.m",
+            "Tests/QuickTests/QuickTests/FunctionalTests/ObjC",
+            "Tests/QuickTests/QuickTests/Helpers",
+            "Tests/QuickTests/QuickTests/QuickConfigurationTests.m",
+        ]
+#if !_runtime(_ObjC)
+        excludes.append("Sources/QuickSpecBase")
+#endif
+        return excludes
+    }()
 )

.travis.yml

@@ -14,6 +14,9 @@ matrix:
       env:
         - PLATFORM=tvos
         - XCODE_ACTION="build-for-testing test-without-building"
+    - os: osx
+      env:
+        - PLATFORM=swiftpm
     - os: osx
       sudo: required
       env:

Package.swift

@@ -2,12 +2,32 @@ import PackageDescription
 
 let package = Package(
     name: "Quick",
-    exclude: [
-      "Sources/QuickObjectiveC",
-      "Tests/QuickTests/QuickAfterSuiteTests/AfterSuiteTests+ObjC.m",
-      "Tests/QuickTests/QuickFocusedTests/FocusedTests+ObjC.m",
-      "Tests/QuickTests/QuickTests/FunctionalTests/ObjC",
-      "Tests/QuickTests/QuickTests/Helpers",
-      "Tests/QuickTests/QuickTests/QuickConfigurationTests.m",
-    ]
+    targets: {
+#if _runtime(_ObjC)
+        return [
+            Target(name: "QuickSpecBase"),
+            Target(name: "Quick", dependencies: [ "QuickSpecBase" ]),
+            Target(name: "QuickTests", dependencies: [ "Quick" ]),
+        ]
+#else
+        return [
+            Target(name: "Quick"),
+            Target(name: "QuickTests", dependencies: [ "Quick" ]),
+        ]
+#endif
+    }(),
+    exclude: {
+        var excludes = [
+            "Sources/QuickObjectiveC",
+            "Tests/QuickTests/QuickAfterSuiteTests/AfterSuiteTests+ObjC.m",
+            "Tests/QuickTests/QuickFocusedTests/FocusedTests+ObjC.m",
+            "Tests/QuickTests/QuickTests/FunctionalTests/ObjC",
+            "Tests/QuickTests/QuickTests/Helpers",
+            "Tests/QuickTests/QuickTests/QuickConfigurationTests.m",
+        ]
+#if !_runtime(_ObjC)
+        excludes.append("Sources/QuickSpecBase")
+#endif
+        return excludes
+    }()
 )

Quick.xcodeproj/project.pbxproj

@@ -483,6 +483,9 @@
 		96327C621C56E90C00405AB3 /* QuickSpec+QuickSpec_MethodList.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = "QuickSpec+QuickSpec_MethodList.m"; sourceTree = "<group>"; };
 		AEB080BB1C72F028004917D3 /* XCTestObservationCenter+QCKSuspendObservation.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = "XCTestObservationCenter+QCKSuspendObservation.m"; sourceTree = "<group>"; };
 		AED9C8621CC8A7BD00432F62 /* CrossReferencingSpecs.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = CrossReferencingSpecs.swift; sourceTree = "<group>"; };
+		CD261AC81DEC8B0000A8863C /* QuickConfiguration.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = QuickConfiguration.swift; sourceTree = "<group>"; };
+		CD3451461E4703D4000C8633 /* QuickMain.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = QuickMain.swift; sourceTree = "<group>"; };
+		CD3451471E4703D4000C8633 /* QuickSpec.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = QuickSpec.swift; sourceTree = "<group>"; };
 		CE57CED81C430BD200D63004 /* NSBundle+CurrentTestBundle.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "NSBundle+CurrentTestBundle.swift"; sourceTree = "<group>"; };
 		CE57CED91C430BD200D63004 /* QuickSelectedTestSuiteBuilder.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = QuickSelectedTestSuiteBuilder.swift; sourceTree = "<group>"; };
 		CE57CEDA1C430BD200D63004 /* QuickTestSuite.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = QuickTestSuite.swift; sourceTree = "<group>"; };
@@ -715,6 +718,7 @@
 			isa = PBXGroup;
 			children = (
 				DA169E4719FF5DF100619816 /* Configuration.swift */,
+				CD261AC81DEC8B0000A8863C /* QuickConfiguration.swift */,
 			);
 			path = Configuration;
 			sourceTree = "<group>";
@@ -860,6 +864,8 @@
 				DA169E4619FF5DF100619816 /* Configuration */,
 				DA3124E119FCAEE8002858A7 /* DSL */,
 				DA408BDE19FF5599005DF92A /* Hooks */,
+				CD3451461E4703D4000C8633 /* QuickMain.swift */,
+				CD3451471E4703D4000C8633 /* QuickSpec.swift */,
 				34F375A619515CA700CE1B99 /* World.swift */,
 				34F3759E19515CA700CE1B99 /* Example.swift */,
 				DA02C91819A8073100093156 /* ExampleMetadata.swift */,

Sources/Quick/Configuration/QuickConfiguration.swift

@@ -1,8 +1,39 @@
+import Foundation
 import XCTest
 
 // NOTE: This file is not intended to be included in the Xcode project or CocoaPods.
 //       It is picked up by the Swift Package Manager during its build process.
 
-open class QuickConfiguration {
+#if SWIFT_PACKAGE
+
+open class QuickConfiguration: NSObject {
     open class func configure(_ configuration: Configuration) {}
 }
+
+#if _runtime(_ObjC)
+
+internal func qck_enumerateSubclasses<T: AnyObject>(_ klass: T.Type, block: (T.Type) -> Void) {
+    var classesCount = objc_getClassList(nil, 0)
+
+    guard classesCount > 0 else {
+        return
+    }
+
+    let classes = UnsafeMutablePointer<AnyClass?>.allocate(capacity: Int(classesCount))
+    classesCount = objc_getClassList(AutoreleasingUnsafeMutablePointer(classes), classesCount)
+
+    var subclass, superclass: AnyClass!
+    for i in 0..<classesCount {
+        subclass = classes[Int(i)]
+        superclass = class_getSuperclass(subclass)
+        if superclass === klass {
+            block(subclass as! T.Type) // swiftlint:disable:this force_cast
+        }
+    }
+
+    free(classes)
+}
+
+#endif
+
+#endif

Sources/Quick/QuickMain.swift

@@ -1,8 +1,10 @@
 import XCTest
-#if os(Linux)
+
 // NOTE: This file is not intended to be included in the Xcode project or CocoaPods.
 //       It is picked up by the Swift Package Manager during its build process.
 
+#if SWIFT_PACKAGE && os(Linux)
+
 /// When using Quick with swift-corelibs-xctest, automatic discovery of specs and
 /// configurations is not available. Instead, you should create a standalone
 /// executable and call this function from its main.swift file. This will execute
@@ -20,14 +22,17 @@ import XCTest
 public func QCKMain(_ specs: [QuickSpec.Type],
                     configurations: [QuickConfiguration.Type] = [],
                     testCases: [XCTestCaseEntry] = []) -> Never {
-    // Perform all configuration (ensures that shared examples have been discovered)
-    World.sharedWorld.configure { configuration in
+    let world = World.sharedWorld
+
+    // Perform all configurations (ensures that shared examples have been discovered)
+    world.configure { configuration in
         for configurationClass in configurations {
             configurationClass.configure(configuration)
         }
     }
-    World.sharedWorld.finalizeConfiguration()
+    world.finalizeConfiguration()
 
     XCTMain(specs.flatMap { testCase($0.allTests) } + testCases)
 }
+
 #endif

Sources/Quick/QuickSpec.swift

@@ -3,10 +3,20 @@ import XCTest
 // NOTE: This file is not intended to be included in the Xcode project or CocoaPods.
 //       It is picked up by the Swift Package Manager during its build process.
 
-open class QuickSpec: XCTestCase {
+#if SWIFT_PACKAGE
+
+#if _runtime(_ObjC)
+import QuickSpecBase
+
+public typealias QuickSpecBase = _QuickSpecBase
+#else
+public typealias QuickSpecBase = XCTestCase
+#endif
+
+open class QuickSpec: QuickSpecBase {
     open func spec() {}
 
-#if os(Linux)
+#if !_runtime(_ObjC)
     public required init() {
         super.init(name: "", testClosure: { _ in })
     }
@@ -17,6 +27,68 @@ open class QuickSpec: XCTestCase {
     public required override init() {
         super.init()
     }
+
+    /// This method is used as a hook for the following two purposes
+    ///
+    /// 1. Performing all configurations
+    /// 2. Gathering examples for each spec classes
+    ///
+    /// On Linux, those are done in `LinuxMain.swift` and `Quick.QCKMain`. But
+    /// SwiftPM on macOS does not have the mechanism (test cases are automatically
+    /// discovered powered by Objective-C runtime), so we needed the alternative
+    /// way.
+    override open class func defaultTestSuite() -> XCTestSuite {
+        let world = World.sharedWorld
+
+        if !world.isConfigurationFinalized {
+            // Perform all configurations (ensures that shared examples have been discovered)
+            world.configure { configuration in
+                qck_enumerateSubclasses(QuickConfiguration.self) { configurationClass in
+                    configurationClass.configure(configuration)
+                }
+            }
+            world.finalizeConfiguration()
+        }
+
+        // Let's gather examples for each spec classes. This has the same effect
+        // as listing spec classes in `LinuxMain.swift` on Linux.
+        _ = allTests
+
+        return super.defaultTestSuite()
+    }
+
+    override open class func _testMethodSelectors() -> [_SelectorWrapper] {
+        let examples = World.sharedWorld.examples(self)
+
+        var selectorNames = Set<String>()
+        return examples.map { example in
+            let selector = addInstanceMethod(for: example, classSelectorNames: &selectorNames)
+            return _SelectorWrapper(selector: selector)
+        }
+    }
+
+    private static func addInstanceMethod(for example: Example, classSelectorNames selectorNames : inout Set<String>) -> Selector {
+        let block: @convention(block) (QuickSpec) -> Void = { _ in
+            example.run()
+        }
+        let implementation = imp_implementationWithBlock(block as Any)
+
+        let originalName = example.name
+        var selectorName = originalName
+        var i: UInt = 2
+
+        while selectorNames.contains(selectorName) {
+            selectorName = String(format: "%@_%tu", originalName, i)
+            i += 1
+        }
+
+        selectorNames.insert(selectorName)
+
+        let selector = NSSelectorFromString(selectorName)
+        class_addMethod(self, selector, implementation, "v@:")
+
+        return selector
+    }
 #endif
 
     static var allTestsCache = [String: [(String, (XCTestCase) -> () throws -> Void)]]()
@@ -46,3 +118,5 @@ open class QuickSpec: XCTestCase {
         }
     }
 }
+
+#endif

Sources/Quick/World.swift

@@ -55,7 +55,8 @@ final internal class World: NSObject {
     private var specs: [String: ExampleGroup] = [:]
     private var sharedExamples: [String: SharedExampleClosure] = [:]
     private let configuration = Configuration()
-    private var isConfigurationFinalized = false
+
+    internal private(set) var isConfigurationFinalized = false
 
     internal var exampleHooks: ExampleHooks {return configuration.exampleHooks }
     internal var suiteHooks: SuiteHooks { return configuration.suiteHooks }

Sources/QuickSpecBase/QuickSpecBase.m

@@ -0,0 +1,55 @@
+#import "QuickSpecBase.h"
+
+#pragma mark - _SelectorWrapper
+
+@interface _SelectorWrapper ()
+@property(nonatomic, assign) SEL selector;
+@end
+
+@implementation _SelectorWrapper
+
+- (instancetype)initWithSelector:(SEL)selector {
+    self = [super init];
+    _selector = selector;
+    return self;
+}
+
+@end
+
+
+#pragma mark - _QuickSpecBase
+
+@implementation _QuickSpecBase
+
+- (instancetype)init {
+    self = [super initWithInvocation: nil];
+    return self;
+}
+
+/**
+ Invocations for each test method in the test case. QuickSpec overrides this method to define a
+ new method for each example defined in +[QuickSpec spec].
+
+ @return An array of invocations that execute the newly defined example methods.
+ */
++ (NSArray<NSInvocation *> *)testInvocations {
+    NSArray<_SelectorWrapper *> *wrappers = [self _testMethodSelectors];
+    NSMutableArray<NSInvocation *> *invocations = [NSMutableArray arrayWithCapacity:wrappers.count];
+
+    for (_SelectorWrapper *wrapper in wrappers) {
+        SEL selector = wrapper.selector;
+        NSMethodSignature *signature = [self instanceMethodSignatureForSelector:selector];
+        NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:signature];
+        invocation.selector = selector;
+
+        [invocations addObject:invocation];
+    }
+
+    return invocations;
+}
+
++ (NSArray<_SelectorWrapper *> *)_testMethodSelectors {
+    return @[];
+}
+
+@end

Sources/QuickSpecBase/include/QuickSpecBase.h

@@ -0,0 +1,11 @@
+@import Foundation;
+@import XCTest;
+
+@interface _SelectorWrapper : NSObject
+- (instancetype)initWithSelector:(SEL)selector;
+@end
+
+@interface _QuickSpecBase : XCTestCase
++ (NSArray<_SelectorWrapper *> *)_testMethodSelectors;
+- (instancetype)init NS_DESIGNATED_INITIALIZER;
+@end

Tests/LinuxMain.swift

@@ -18,8 +18,8 @@ Quick.QCKMain([
     Configuration_BeforeEachSpec.self,
     FunctionalTests_CrossReferencingSpecA.self,
     FunctionalTests_CrossReferencingSpecB.self,
-    FunctionalTests_FocusedSpec_Focused.self,
-    FunctionalTests_FocusedSpec_Unfocused.self
+    _FunctionalTests_FocusedSpec_Focused.self,
+    _FunctionalTests_FocusedSpec_Unfocused.self
 ],
 configurations: [
     FunctionalTests_SharedExamples_BeforeEachTests_SharedExamples.self,