foo.diff

diff --git a/WordPress/Classes/Services/Store.swift b/WordPress/Classes/Services/Store.swift
index daa668b..e8112f6 100644
--- a/WordPress/Classes/Services/Store.swift
+++ b/WordPress/Classes/Services/Store.swift
@@ -30,6 +30,10 @@ struct StoreKitCoordinator {
 
 typealias PendingPayment = (planID: PlanID, productID: String, siteID: Int)
 
+enum StoreCoordinatorError: ErrorType {
+    case PaymentAlreadyInProgress
+}
+
 /// StoreCoordinator coordinates purchasing of products, processing of transactions, and
 /// verification of purchases between the App Store (StoreKit) and WordPress.com.
 ///
@@ -45,7 +49,7 @@ typealias PendingPayment = (planID: PlanID, productID: String, siteID: Int)
 class StoreCoordinator<S: Store> {
     private let store: S
     
-    var pendingPayment: PendingPayment? {
+    private var pendingPayment: PendingPayment? {
         set {
             let defaults = NSUserDefaults.standardUserDefaults()
             
@@ -74,16 +78,16 @@ class StoreCoordinator<S: Store> {
 
     init(store: S) {
         self.store = store
+        self.pendingPayment = nil
     }
 
     /// Initiates a purchase for the specified plan if a purchase isn't already in progress.
-    func purchasePlan(plan: Plan, product: S.ProductType, forSite siteID: Int) {
+    func purchasePlan(plan: Plan, product: S.ProductType, forSite siteID: Int) throws {
         precondition(plan.productIdentifier == product.productIdentifier)
         
         // We _should_ never have a pending payment at this point, so we'll fail in that case.
         guard pendingPayment == nil else {
-            postTransactionFailedNotification([StoreKitCoordinator.NotificationProductIdentifierKey: product.productIdentifier])
-            return
+            throw StoreCoordinatorError.PaymentAlreadyInProgress
         }
         
         pendingPayment = (plan.id, product.productIdentifier, siteID)
diff --git a/WordPress/Classes/ViewRelated/Plans/PlanDetailViewController.swift b/WordPress/Classes/ViewRelated/Plans/PlanDetailViewController.swift
index a32306a..04577da 100644
--- a/WordPress/Classes/ViewRelated/Plans/PlanDetailViewController.swift
+++ b/WordPress/Classes/ViewRelated/Plans/PlanDetailViewController.swift
@@ -269,7 +269,11 @@ class PlanDetailViewController: UIViewController {
         store.getProductsWithIdentifiers(
             Set([identifier]),
             success: { [viewModel] products in
-                StoreKitCoordinator.instance.purchasePlan(viewModel.plan, product: products[0], forSite: viewModel.siteID)
+                do {
+                    try StoreKitCoordinator.instance.purchasePlan(viewModel.plan, product: products[0], forSite: viewModel.siteID)
+                } catch StoreError.PaymentAlreadyInProgress {
+                    self.purchaseButton?.selected = false
+                } catch {}
             },
             failure: { error in
                 DDLogSwift.logError("Error fetching Store products: \(error)")
diff --git a/WordPress/WordPressTest/StoreCoordinatorTests.swift b/WordPress/WordPressTest/StoreCoordinatorTests.swift
index 516d246..f16309a 100644
--- a/WordPress/WordPressTest/StoreCoordinatorTests.swift
+++ b/WordPress/WordPressTest/StoreCoordinatorTests.swift
@@ -56,33 +56,24 @@ class StoreCoordinatorTests: XCTestCase {
         XCTAssertEqual(availability, PurchaseAvailability.available)
     }
 
-    func testPendingPaymentStoredWhenAllValuesPresent() {
-        let payment: PendingPayment = (5, testProduct, 1000)
+    func testCannotPurchaseWhenPurchaseAlreadyPending() {
+        let payment: PendingPayment = (premium.id, testProduct, testSite)
         let coordinator = storeCoordinator(paymentsEnabled: true, pending: payment)
-        
-        XCTAssertEqual(coordinator.pendingPayment?.planID, payment.planID)
-        XCTAssertEqual(coordinator.pendingPayment?.productID, payment.productID)
-        XCTAssertEqual(coordinator.pendingPayment?.siteID, payment.siteID)
-    }
-    
-    func testPendingPaymentHandlesNil() {
-        let payment: PendingPayment? = nil
-        let coordinator = storeCoordinator(paymentsEnabled: true, pending: payment)
-        
-        XCTAssertNil(coordinator.pendingPayment)
+        let product = productForPlan(TestPlans.business.plan)
+
+        // And now attempt a second purchase
+        XCTAssertThrowsError(try coordinator.purchasePlan(business, product: product, forSite: testSite))
     }
     
-    func testExistingPendingPaymentIsClearedWhenSetToNil() {
-        let payment: PendingPayment = (5, testProduct, 1000)
-        let coordinator = storeCoordinator(paymentsEnabled: true, pending: payment)
-        
-        XCTAssertEqual(coordinator.pendingPayment?.planID, payment.planID)
-        XCTAssertEqual(coordinator.pendingPayment?.productID, payment.productID)
-        XCTAssertEqual(coordinator.pendingPayment?.siteID, payment.siteID)
-        
-        coordinator.pendingPayment = nil
-        
-        XCTAssertNil(coordinator.pendingPayment)
+    func testCanMakePaymentWhenNoPaymentIsPending() {
+        let coordinator = storeCoordinator(paymentsEnabled: true, pending: nil)
+        let product = productForPlan(TestPlans.business.plan)
+
+        do {
+            try coordinator.purchasePlan(business, product: product, forSite: otherSite)
+        } catch {
+            XCTFail("Expected call not to throw")
+        }
     }
     
     // ========================= END OF TESTS =============================== //
@@ -99,10 +90,25 @@ class StoreCoordinatorTests: XCTestCase {
     private func storeCoordinator(paymentsEnabled paymentsEnabled: Bool, pending: PendingPayment?) -> StoreCoordinator<MockStore> {
         var store = MockStore.succeeding()
         store.canMakePayments = paymentsEnabled
+ 
         let coordinator = StoreCoordinator(store: store)
-        coordinator.pendingPayment = pending
+        
+        if let pending = pending,
+            let plan = TestPlans.allPlans.filter({ $0.id == pending.planID }).first {
+            let product = productForPlan(plan)
+            try! coordinator.purchasePlan(plan, product: product, forSite: pending.siteID)
+        }
+        
         return coordinator
     }
+    
+    private func productForPlan(plan: Plan) -> MockProduct {
+        return MockProduct(localizedDescription: plan.tagline,
+                           localizedTitle: plan.title,
+                           price: 299.99,
+                           priceLocale: NSLocale.currentLocale(),
+                           productIdentifier: plan.productIdentifier!)
+    }
 
     private func pending(plan plan: Plan, productID: String, siteID: Int, state: PendingState) -> PendingPayment? {
         switch state {