killbill-memoizeit

diff --git a/invoice/src/test/java/org/killbill/billing/invoice/proRations/inAdvance/annual/TestProRation.java b/invoice/src/test/java/org/killbill/billing/invoice/proRations/inAdvance/annual/TestProRation.java
index e56b43f..f1f0399 100644
--- a/invoice/src/test/java/org/killbill/billing/invoice/proRations/inAdvance/annual/TestProRation.java
+++ b/invoice/src/test/java/org/killbill/billing/invoice/proRations/inAdvance/annual/TestProRation.java
@@ -1,7 +1,9 @@
 /*
  * Copyright 2010-2013 Ning, Inc.
+ * Copyright 2014-2016 Groupon, Inc
+ * Copyright 2014-2016 The Billing Project, LLC
  *
- * Ning licenses this file to you under the Apache License, version 2.0
+ * The Billing Project licenses this file to you under the Apache License, version 2.0
  * (the "License"); you may not use this file except in compliance with the
  * License.  You may obtain a copy of the License at:
  *
@@ -16,17 +18,22 @@
 
 package org.killbill.billing.invoice.proRations.inAdvance.annual;
 
-import static org.killbill.billing.invoice.TestInvoiceHelper.*;
-
 import java.math.BigDecimal;
 
 import org.joda.time.LocalDate;
-import org.testng.annotations.Test;
-
 import org.killbill.billing.catalog.api.BillingPeriod;
 import org.killbill.billing.invoice.model.InvalidDateSequenceException;
 import org.killbill.billing.invoice.proRations.inAdvance.ProRationInAdvanceTestBase;
 import org.killbill.billing.util.currency.KillBillMoney;
+import org.testng.annotations.Test;
+
+import static org.killbill.billing.invoice.TestInvoiceHelper.FORTY_SEVEN;
+import static org.killbill.billing.invoice.TestInvoiceHelper.ONE;
+import static org.killbill.billing.invoice.TestInvoiceHelper.SEVEN;
+import static org.killbill.billing.invoice.TestInvoiceHelper.THREE_HUNDRED_AND_FIFTY_FOUR;
+import static org.killbill.billing.invoice.TestInvoiceHelper.THREE_HUNDRED_AND_FOURTY_NINE;
+import static org.killbill.billing.invoice.TestInvoiceHelper.THREE_HUNDRED_AND_SIXTY_FIVE;
+import static org.killbill.billing.invoice.TestInvoiceHelper.THREE_HUNDRED_AND_SIXTY_SIX;
 
 public class TestProRation extends ProRationInAdvanceTestBase {
 
@@ -55,14 +62,17 @@ public class TestProRation extends ProRationInAdvanceTestBase {
         testCalculateNumberOfBillingCycles(startDate, targetDate, 4, expectedValue);
     }
 
-    // TODO Test fails, needs to be investigated
-    @Test(groups = "fast", enabled = false)
+    @Test(groups = "fast")
     public void testSinglePlanDoubleProRation() throws InvalidDateSequenceException {
         final LocalDate startDate = invoiceUtil.buildDate(2011, 1, 10);
         final LocalDate endDate = invoiceUtil.buildDate(2012, 3, 4);
         final LocalDate targetDate = invoiceUtil.buildDate(2012, 4, 5);
 
-        final BigDecimal expectedValue = BigDecimal.ZERO;
+        // SEVEN is number of days between startDate and expected first billing cycle date (2011, 1, 17);
+        // FORTY_SEVEN is number of days between the second billing cycle date (2012, 1, 17) and the end date (2012, 3, 4);
+        // 2011 has 365 days but 2012 has 366 days
+        final BigDecimal expectedValue = ONE.add(SEVEN.divide(THREE_HUNDRED_AND_SIXTY_FIVE, KillBillMoney.ROUNDING_METHOD))
+                                            .add(FORTY_SEVEN.divide(THREE_HUNDRED_AND_SIXTY_SIX, KillBillMoney.ROUNDING_METHOD));
         testCalculateNumberOfBillingCycles(startDate, endDate, targetDate, 17, expectedValue);
     }
 }

diff --git a/invoice/src/test/java/org/killbill/billing/invoice/TestInvoiceHelper.java b/invoice/src/test/java/org/killbill/billing/invoice/TestInvoiceHelper.java
index 4e2d5f6..3cc1c21 100644
--- a/invoice/src/test/java/org/killbill/billing/invoice/TestInvoiceHelper.java
+++ b/invoice/src/test/java/org/killbill/billing/invoice/TestInvoiceHelper.java
@@ -128,6 +128,7 @@ public class TestInvoiceHelper {
     public static final BigDecimal THIRTY_THREE = new BigDecimal("33.0").setScale(KillBillMoney.MAX_SCALE);
 
     public static final BigDecimal FORTY = new BigDecimal("40.0").setScale(KillBillMoney.MAX_SCALE);
+    public static final BigDecimal FORTY_SEVEN = new BigDecimal("47.0").setScale(KillBillMoney.MAX_SCALE);
     public static final BigDecimal SIXTY_SIX = new BigDecimal("66.0").setScale(KillBillMoney.MAX_SCALE);
     public static final BigDecimal SEVENTY_FIVE = new BigDecimal("75.0").setScale(KillBillMoney.MAX_SCALE);