adding when(fulfilled:) and when(resolved:) tuple overloads and an associated type R representing the result type in Thenable which improves when(resolved:) return type

Author: Skoti

PromiseKit.xcodeproj/project.pbxproj

@@ -12,6 +12,7 @@
 		0C42F31B1FCF86320051309C /* HangTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0C42F3191FCF86240051309C /* HangTests.swift */; };
 		0CC3AF2B1FCF84F7000E98C9 /* hang.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0CC3AF2A1FCF84F7000E98C9 /* hang.swift */; };
 		49A5584D1DC5185900E4D01B /* ResolverTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 49A5584B1DC5172F00E4D01B /* ResolverTests.swift */; };
+		6220BC2723114E580032BE32 /* TestError.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6220BC2623114E580032BE32 /* TestError.swift */; };
 		630A8056203CEF6800D25F23 /* AnyPromiseTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 630A8051203CEF6800D25F23 /* AnyPromiseTests.m */; settings = {COMPILER_FLAGS = "-fobjc-arc-exceptions"; }; };
 		630A8057203CEF6800D25F23 /* PMKManifoldTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 630A8052203CEF6800D25F23 /* PMKManifoldTests.m */; };
 		630A8058203CEF6800D25F23 /* JoinTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 630A8053203CEF6800D25F23 /* JoinTests.m */; };
@@ -144,6 +145,7 @@
 		0C42F3191FCF86240051309C /* HangTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = HangTests.swift; sourceTree = "<group>"; };
 		0CC3AF2A1FCF84F7000E98C9 /* hang.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = hang.swift; path = Sources/hang.swift; sourceTree = "<group>"; };
 		49A5584B1DC5172F00E4D01B /* ResolverTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ResolverTests.swift; sourceTree = "<group>"; };
+		6220BC2623114E580032BE32 /* TestError.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TestError.swift; sourceTree = "<group>"; };
 		630019221D596292003B4E30 /* PMKCoreTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = PMKCoreTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
 		630A8051203CEF6800D25F23 /* AnyPromiseTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = AnyPromiseTests.m; sourceTree = "<group>"; };
 		630A8052203CEF6800D25F23 /* PMKManifoldTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = PMKManifoldTests.m; sourceTree = "<group>"; };
@@ -352,6 +354,7 @@
 				635D640D1D59635300BC0AF5 /* ZalgoTests.swift */,
 				639BF755203DF02C00FA577B /* Utilities.swift */,
 				085B96B121A6358900E5E22F /* LoggingTests.swift */,
+				6220BC2623114E580032BE32 /* TestError.swift */,
 			);
 			name = Core;
 			path = Tests/CorePromise;
@@ -757,6 +760,7 @@
 				636A291F1F1C16FF001229C2 /* Box.swift in Sources */,
 				63B0AC821D595E6300FA21D9 /* AnyPromise.m in Sources */,
 				636A29231F1C17A6001229C2 /* Guarantee.swift in Sources */,
+				6220BC2723114E580032BE32 /* TestError.swift in Sources */,
 				636A291A1F1C156B001229C2 /* Promise.swift in Sources */,
 				63B0AC8B1D595E6300FA21D9 /* join.m in Sources */,
 				63B0AC891D595E6300FA21D9 /* hang.m in Sources */,

Sources/Guarantee.swift

@@ -45,12 +45,12 @@ public final class Guarantee<T>: Thenable {
     }
 
     /// - See: `Thenable.result`
-    public var result: Result<T>? {
+    public var result: T? {
         switch box.inspect() {
         case .pending:
             return nil
         case .resolved(let value):
-            return .fulfilled(value)
+            return value
         }
     }
 
@@ -125,7 +125,6 @@ public extension Guarantee {
      any part of your chain may use. Like the main thread for example.
      */
     func wait() -> T {
-
         if Thread.isMainThread {
             conf.logHandler(.waitOnMainThread)
         }

Sources/Resolver.swift

@@ -88,6 +88,7 @@ public enum Result<T> {
 }
 
 public extension PromiseKit.Result {
+    
     var isFulfilled: Bool {
         switch self {
         case .fulfilled:
@@ -96,4 +97,22 @@ public extension PromiseKit.Result {
             return false
         }
     }
+    
+    var value: T? {
+        switch self {
+        case let .fulfilled(value):
+            return value
+        case .rejected:
+            return nil
+        }
+    }
+    
+    var error: Error? {
+        switch self {
+        case let .rejected(error):
+            return error
+        case .fulfilled:
+            return nil
+        }
+    }
 }

Sources/Thenable.swift

@@ -4,15 +4,21 @@ import Dispatch
 public protocol Thenable: class {
     /// The type of the wrapped value
     associatedtype T
+    /// The type of the result
+    associatedtype R
 
     /// `pipe` is immediately executed when this `Thenable` is resolved
     func pipe(to: @escaping(Result<T>) -> Void)
 
     /// The resolved result or nil if pending.
-    var result: Result<T>? { get }
+    var result: R? { get }
+    
+    /// The resolved result's value or nil if pending.
+    var value: T? { get }
 }
 
 public extension Thenable {
+    
     /**
      The provided closure executes when this promise is fulfilled.
 
@@ -217,60 +223,57 @@ public extension Thenable {
 }
 
 public extension Thenable {
+    
     /**
-     - Returns: The error with which this promise was rejected; `nil` if this promise is not rejected.
-     */
-    var error: Error? {
-        switch result {
-        case .none:
-            return nil
-        case .some(.fulfilled):
-            return nil
-        case .some(.rejected(let error)):
-            return error
-        }
-    }
-
-    /**
-     - Returns: `true` if the promise has not yet resolved.
+     - Returns: `true` if this thenable has not yet resolved.
      */
     var isPending: Bool {
         return result == nil
     }
 
     /**
-     - Returns: `true` if the promise has resolved.
+     - Returns: `true` if this thenable has resolved.
      */
     var isResolved: Bool {
         return !isPending
     }
+}
+
+public extension Thenable where R == T {
+    
+    var value: T? {
+        return result
+    }
+}
 
+public extension Thenable where R == Result<Self.T> {
+    
     /**
-     - Returns: `true` if the promise was fulfilled.
+     - Returns: `true` if this thenable was fulfilled.
      */
     var isFulfilled: Bool {
         return value != nil
     }
-
+    
+    /**
+     - Returns: The value with which this thenable was fulfilled or `nil` if this thenable is pending or rejected.
+     */
+    var value: T? {
+        return result?.value
+    }
+    
     /**
-     - Returns: `true` if the promise was rejected.
+     - Returns: `true` if this thenable was rejected.
      */
     var isRejected: Bool {
         return error != nil
     }
-
+    
     /**
-     - Returns: The value with which this promise was fulfilled or `nil` if this promise is pending or rejected.
+     - Returns: The error with which this thenable was rejected; `nil` if this thenable is not rejected or pending.
      */
-    var value: T? {
-        switch result {
-        case .none:
-            return nil
-        case .some(.fulfilled(let value)):
-            return value
-        case .some(.rejected):
-            return nil
-        }
+    var error: Error? {
+        return result?.error
     }
 }