Fix Swift 4.2 compatibility on Linux

.travis.yml

@@ -16,21 +16,37 @@ matrix:
       osx_image: xcode9.4
     - os: osx
       env: TYPE=macos
-      osx_image: xcode10
+      osx_image: xcode10.1
     - os: osx
       env:
         - TYPE=swiftpm
     - os: osx
       env:
         - TYPE=swiftpm
-      osx_image: xcode10
+      osx_image: xcode10.1
     - os: linux
       dist: trusty
       sudo: required
       env:
         - TYPE=swiftpm
       install:
         - eval "$(curl -sL https://gist.githubusercontent.com/kylef/5c0475ff02b7c7671d2a/raw/9f442512a46d7a2af7b850d65a7e9bd31edfb09b/swiftenv-install.sh)"
+    - os: linux
+      dist: trusty
+      sudo: required
+      env:
+        - TYPE=swiftpm
+        - SWIFT_VERSION=4.2.1
+      install:
+        - eval "$(curl -sL https://gist.githubusercontent.com/kylef/5c0475ff02b7c7671d2a/raw/9f442512a46d7a2af7b850d65a7e9bd31edfb09b/swiftenv-install.sh)"
+    - os: linux
+      dist: trusty
+      sudo: required
+      env:
+        - TYPE=swiftpm
+        - SWIFT_VERSION=5.0-DEVELOPMENT-SNAPSHOT-2019-01-13-a
+      install:
+        - eval "$(curl -sL https://gist.githubusercontent.com/kylef/5c0475ff02b7c7671d2a/raw/9f442512a46d7a2af7b850d65a7e9bd31edfb09b/swiftenv-install.sh)"
 install:
   - if [[ "$TYPE" == "podspec" ]]; then sudo gem install bundler; bundle install; fi
 script:

Sources/Nimble/Adapters/NimbleEnvironment.swift

@@ -3,7 +3,7 @@ import Foundation
 
 /// "Global" state of Nimble is stored here. Only DSL functions should access / be aware of this
 /// class' existence
-internal class NimbleEnvironment {
+internal class NimbleEnvironment: NSObject {
     static var activeInstance: NimbleEnvironment {
         get {
             let env = Thread.current.threadDictionary["NimbleEnvironment"]
@@ -30,11 +30,14 @@ internal class NimbleEnvironment {
     var suppressTVOSAssertionWarning: Bool = false
     var awaiter: Awaiter
 
-    init() {
+    override init() {
         let timeoutQueue = DispatchQueue.global(qos: .userInitiated)
         awaiter = Awaiter(
             waitLock: AssertionWaitLock(),
             asyncQueue: .main,
-            timeoutQueue: timeoutQueue)
+            timeoutQueue: timeoutQueue
+        )
+
+        super.init()
     }
 }

Sources/Nimble/Matchers/BeIdenticalTo.swift

@@ -4,14 +4,14 @@ import Foundation
 /// as the expected instance.
 public func beIdenticalTo(_ expected: Any?) -> Predicate<Any> {
     return Predicate.define { actualExpression in
-        #if os(Linux)
+        #if os(Linux) && !swift(>=4.1.50)
             let actual = try actualExpression.evaluate() as? AnyObject
         #else
             let actual = try actualExpression.evaluate() as AnyObject?
         #endif
 
         let bool: Bool
-        #if os(Linux)
+        #if os(Linux) && !swift(>=4.1.50)
             bool = actual === (expected as? AnyObject) && actual !== nil
         #else
             bool = actual === (expected as AnyObject?) && actual !== nil

Sources/Nimble/Utils/Await.swift

@@ -261,7 +261,7 @@ internal class AwaitPromiseBuilder<T> {
             self.trigger.timeoutSource.resume()
             while self.promise.asyncResult.isIncomplete() {
                 // Stopping the run loop does not work unless we run only 1 mode
-                #if swift(>=4.2)
+                #if swift(>=4.2) && (os(macOS) || os(iOS) || os(tvOS))
                 _ = RunLoop.current.run(mode: .default, before: .distantFuture)
                 #else
                 _ = RunLoop.current.run(mode: .defaultRunLoopMode, before: .distantFuture)

Sources/Nimble/Utils/Stringers.swift

@@ -2,7 +2,7 @@ import Foundation
 
 internal func identityAsString(_ value: Any?) -> String {
     let anyObject: AnyObject?
-#if os(Linux)
+#if os(Linux) && !swift(>=4.1.50)
     anyObject = value as? AnyObject
 #else
     anyObject = value as AnyObject?

test

@@ -84,7 +84,7 @@ function test_podspec {
 
 function test_swiftpm {
     if [ -d .build ]; then
-        run swift build --clean
+        run swift package clean
     fi
     run swift build && swift test
 }