Modernizes the API and improves unit test.

Author: kzaher

RxCocoa/iOS/UIStepper+Rx.swift

@@ -27,8 +27,8 @@ extension Reactive where Base: UIStepper {
     }
 
     /// Reactive wrapper for `stepValue` property.
-    public var stepValue: UIBindingObserver<Base, Double> {
-        return UIBindingObserver(UIElement: self.base) { stepper, value in
+    public var stepValue: Binder<Double> {
+        return Binder(self.base) { stepper, value in
             stepper.stepValue = value
         }
     }

Tests/RxCocoaTests/UIStepper+RxTests.swift

@@ -26,6 +26,10 @@ import XCTest
         func testStepper_stepValueObserver() {
             let stepper = UIStepper()
             let stepValue: Double = 0.42
+
+            stepper.stepValue = 1.0
+            XCTAssertEqualWithAccuracy(stepper.stepValue, 1.0, accuracy: 0.0001)
+
             Observable.just(stepValue).bind(to: stepper.rx.stepValue).dispose()
             XCTAssertEqualWithAccuracy(stepper.stepValue, stepValue, accuracy: 0.0001)
         }