Implemented stop() and added valid() to check if repeater is running

TDDTimer/Components/Repeater/DefaultRepeater.swift

@@ -6,11 +6,11 @@ protocol Repeater {
 }
 
 class DefaultRepeater: Repeater {
-    var timer: NSTimer?
-    var closureToRepeat: (() -> ())?
+    private var maybeTimer: NSTimer?
+    private var closureToRepeat: (() -> ())?
 
     func start(timeInterval: NSTimeInterval, closureToRepeat: (() -> ())?) {
-        timer = NSTimer.scheduledTimerWithTimeInterval(
+        maybeTimer = NSTimer.scheduledTimerWithTimeInterval(
             timeInterval,
             target: self,
             selector: #selector(timerInvocation),
@@ -22,7 +22,16 @@ class DefaultRepeater: Repeater {
     }
 
     func stop() {
-        // TODO
+        maybeTimer?.invalidate()
+    }
+
+    func valid() -> Bool {
+
+        if let timer = maybeTimer {
+            return timer.valid
+        }
+
+        return false
     }
 
     // MARK: - Private Methods

TDDTimerTests/Components/Repeater/DefaultRepeaterTest.swift

@@ -22,6 +22,39 @@ class DefaultRepeaterTest: QuickSpec {
                 expect(closureWasCalled).to(beTrue())
             }
 
+            it("reports valid status when running") {
+                let defaultRepeater = DefaultRepeater()
+
+
+                var isValid = false
+                defaultRepeater.start(0.01) {
+                    isValid = defaultRepeater.valid()
+                }
+
+
+                NSRunLoop.advance()
+
+                expect(isValid).to(beTrue())
+            }
+
+            it("reports invalid status when not running") {
+                let defaultRepeater = DefaultRepeater()
+
+                expect(defaultRepeater.valid()).to(beFalse())
+            }
+
+            it("stops running after calling stop") {
+                let defaultRepeater = DefaultRepeater()
+
+
+                defaultRepeater.start(0.01) {}
+                NSRunLoop.advance()
+                defaultRepeater.stop()
+
+
+                expect(defaultRepeater.valid()).to(beFalse())
+            }
+
         }
     }
 }