Add configure.isFinished & always call configure.cancel() on finished.

Author: inamiy

SwiftTask/SwiftTask.swift

@@ -28,16 +28,29 @@ public class TaskConfiguration
     public var resume: (Void -> Void)?
     public var cancel: (Void -> Void)?
 
+    /// useful to terminate immediate-infinite-sequence while performing `initClosure`
+    public private(set) var isFinished: Bool = false
+    
     public init()
     {
 
     }
 
-    internal func clear()
+    internal func finish()
     {
+        //
+        // Cancel anyway on task finished (fulfilled/rejected/cancelled).
+        //
+        // NOTE:
+        // ReactKit uses this closure to call `upstreamSignal.cancel()`
+        // and let it know `configure.isFinished = true` while performing its `initClosure`.
+        //
+        self.cancel?()
+        
         self.pause = nil
         self.resume = nil
         self.cancel = nil
+        self.isFinished = true
     }
 }
 

SwiftTask/_StateMachine.swift

@@ -73,7 +73,7 @@ internal class _StateMachine<Progress, Value, Error>
         if self.state == .Running {
             self.state = .Fulfilled
             self.value = value
-            self.complete()
+            self.finish()
         }
     }
 
@@ -82,7 +82,7 @@ internal class _StateMachine<Progress, Value, Error>
         if self.state == .Running || self.state == .Paused {
             self.state = errorInfo.isCancelled ? .Cancelled : .Rejected
             self.errorInfo = errorInfo
-            self.complete()
+            self.finish()
         }
     }
 
@@ -157,33 +157,26 @@ internal class _StateMachine<Progress, Value, Error>
     internal func handleCancel(error: Error? = nil) -> Bool
     {
         if self.state == .Running || self.state == .Paused {
-            
             self.state = .Cancelled
             self.errorInfo = ErrorInfo(error: error, isCancelled: true)
-            self.complete {
-                // NOTE: call `configuration.cancel()` after all `completionHandlers` are invoked
-                self.configuration.cancel?()
-                return
-            }
-            
+            self.finish()
             return true
         }
         else {
             return false
         }
     }
 
-    internal func complete(closure: (Void -> Void)? = nil)
+    internal func finish()
     {
         for handler in self.completionHandlers {
             handler()
         }
 
-        closure?()
-        
         self.progressTupleHandlers.removeAll()
         self.completionHandlers.removeAll()
-        self.configuration.clear()
+        
+        self.configuration.finish()
 
         self.initResumeClosure = nil
         self.progress = nil