killbill-memoizeit

diff --git a/invoice/src/main/java/org/killbill/billing/invoice/generator/DefaultInvoiceGenerator.java b/invoice/src/main/java/org/killbill/billing/invoice/generator/DefaultInvoiceGenerator.java
index 89a9905..66eb264 100644
--- a/invoice/src/main/java/org/killbill/billing/invoice/generator/DefaultInvoiceGenerator.java
+++ b/invoice/src/main/java/org/killbill/billing/invoice/generator/DefaultInvoiceGenerator.java
@@ -135,7 +135,7 @@ public class DefaultInvoiceGenerator implements InvoiceGenerator {
 
                 final UUID subscriptionId = event.getSubscription().getId();
                 if (curSubscriptionId != null && !curSubscriptionId.equals(subscriptionId)) {
-                    final SubscriptionConsumableInArrear subscriptionConsumableInArrear = new SubscriptionConsumableInArrear(invoiceId, curEvents, usageApi, targetDate, context.toTenantContext(tenantId));
+                    final SubscriptionConsumableInArrear subscriptionConsumableInArrear = new SubscriptionConsumableInArrear(invoiceId, curEvents, usageApi, config.isInsertZeroUsageItems(), targetDate, context.toTenantContext(tenantId));
                     items.addAll(subscriptionConsumableInArrear.computeMissingUsageInvoiceItems(extractUsageItemsForSubscription(curSubscriptionId, existingInvoices)));
                     curEvents = Lists.newArrayList();
                 }
@@ -143,7 +143,7 @@ public class DefaultInvoiceGenerator implements InvoiceGenerator {
                 curEvents.add(event);
             }
             if (curSubscriptionId != null) {
-                final SubscriptionConsumableInArrear subscriptionConsumableInArrear = new SubscriptionConsumableInArrear(invoiceId, curEvents, usageApi, targetDate, context.toTenantContext(tenantId));
+                final SubscriptionConsumableInArrear subscriptionConsumableInArrear = new SubscriptionConsumableInArrear(invoiceId, curEvents, usageApi, config.isInsertZeroUsageItems(), targetDate, context.toTenantContext(tenantId));
                 items.addAll(subscriptionConsumableInArrear.computeMissingUsageInvoiceItems(extractUsageItemsForSubscription(curSubscriptionId, existingInvoices)));
             }
             return items;

diff --git a/invoice/src/main/java/org/killbill/billing/invoice/usage/ContiguousIntervalConsumableInArrear.java b/invoice/src/main/java/org/killbill/billing/invoice/usage/ContiguousIntervalConsumableInArrear.java
index 69beb39..dcb30e1 100644
--- a/invoice/src/main/java/org/killbill/billing/invoice/usage/ContiguousIntervalConsumableInArrear.java
+++ b/invoice/src/main/java/org/killbill/billing/invoice/usage/ContiguousIntervalConsumableInArrear.java
@@ -69,12 +69,14 @@ public class ContiguousIntervalConsumableInArrear {
     private final UUID invoiceId;
     private final TenantContext context;
     private final AtomicBoolean isBuilt;
+    private final boolean insertZeroAmountItems;
 
-    public ContiguousIntervalConsumableInArrear(final Usage usage, final UUID invoiceId, final UsageUserApi usageApi, final LocalDate targetDate, final TenantContext context) {
+    public ContiguousIntervalConsumableInArrear(final Usage usage, final UUID invoiceId, final UsageUserApi usageApi, final boolean insertZeroAmountItems, final LocalDate targetDate, final TenantContext context) {
         this.usage = usage;
         this.invoiceId = invoiceId;
         this.unitTypes = getConsumableInArrearUnitTypes(usage);
         this.usageApi = usageApi;
+        this.insertZeroAmountItems = insertZeroAmountItems;
         this.targetDate = targetDate;
         this.context = context;
         this.billingEvents = Lists.newLinkedList();
@@ -149,12 +151,14 @@ public class ContiguousIntervalConsumableInArrear {
             final Iterable<InvoiceItem> billedItems = getBilledItems(ru.getStartDate(), ru.getEndDate(), existingUsage);
             final BigDecimal billedUsage = computeBilledUsage(billedItems);
 
-            // Compare the two and add the missing piece if required. If there has never been any billed item for the period
-            // and if there is nothing to bill for we would also insert a $0 amount
+            // Compare the two and add the missing piece if required.
             if (!billedItems.iterator().hasNext() || billedUsage.compareTo(toBeBilledUsage) < 0) {
-                InvoiceItem item = new UsageInvoiceItem(invoiceId, getAccountId(), getBundleId(), getSubscriptionId(), getPlanName(),
-                                                        getPhaseName(), usage.getName(), ru.getStartDate(), ru.getEndDate(), toBeBilledUsage.subtract(billedUsage), getCurrency());
-                result.add(item);
+                final BigDecimal amountToBill = toBeBilledUsage.subtract(billedUsage);
+                if (amountToBill.compareTo(BigDecimal.ZERO) > 0 || insertZeroAmountItems) {
+                    InvoiceItem item = new UsageInvoiceItem(invoiceId, getAccountId(), getBundleId(), getSubscriptionId(), getPlanName(),
+                                                            getPhaseName(), usage.getName(), ru.getStartDate(), ru.getEndDate(), amountToBill, getCurrency());
+                    result.add(item);
+                }
             }
 
         }

diff --git a/invoice/src/main/java/org/killbill/billing/invoice/usage/SubscriptionConsumableInArrear.java b/invoice/src/main/java/org/killbill/billing/invoice/usage/SubscriptionConsumableInArrear.java
index 6707195..8da11ed 100644
--- a/invoice/src/main/java/org/killbill/billing/invoice/usage/SubscriptionConsumableInArrear.java
+++ b/invoice/src/main/java/org/killbill/billing/invoice/usage/SubscriptionConsumableInArrear.java
@@ -24,8 +24,6 @@ import java.util.Map;
 import java.util.Set;
 import java.util.UUID;
 
-import javax.annotation.Nullable;
-
 import org.joda.time.LocalDate;
 import org.killbill.billing.catalog.api.BillingMode;
 import org.killbill.billing.catalog.api.CatalogApiException;
@@ -39,7 +37,6 @@ import org.killbill.billing.util.callcontext.TenantContext;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Function;
 import com.google.common.collect.Collections2;
-import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
 
 /**
@@ -52,11 +49,13 @@ public class SubscriptionConsumableInArrear {
     private final UsageUserApi usageApi;
     private final LocalDate targetDate;
     private final TenantContext context;
+    private final boolean insertZeroAmountItems;
 
-    public SubscriptionConsumableInArrear(final UUID invoiceId, final List<BillingEvent> subscriptionBillingEvents, final UsageUserApi usageApi, final LocalDate targetDate, final TenantContext context) {
+    public SubscriptionConsumableInArrear(final UUID invoiceId, final List<BillingEvent> subscriptionBillingEvents, final UsageUserApi usageApi, final boolean insertZeroAmountItems, LocalDate targetDate, final TenantContext context) {
         this.invoiceId = invoiceId;
         this.subscriptionBillingEvents = subscriptionBillingEvents;
         this.usageApi = usageApi;
+        this.insertZeroAmountItems = insertZeroAmountItems;
         this.targetDate = targetDate;
         this.context = context;
     }
@@ -107,7 +106,7 @@ public class SubscriptionConsumableInArrear {
                 // Add inflight usage interval if non existent
                 ContiguousIntervalConsumableInArrear existingInterval = inFlightInArrearUsageIntervals.get(usage.getName());
                 if (existingInterval == null) {
-                    existingInterval = new ContiguousIntervalConsumableInArrear(usage, invoiceId, usageApi, targetDate, context);
+                    existingInterval = new ContiguousIntervalConsumableInArrear(usage, invoiceId, usageApi, insertZeroAmountItems, targetDate, context);
                     inFlightInArrearUsageIntervals.put(usage.getName(), existingInterval);
                 }
                 // Add billing event for that usage interval

diff --git a/invoice/src/test/java/org/killbill/billing/invoice/generator/TestDefaultInvoiceGenerator.java b/invoice/src/test/java/org/killbill/billing/invoice/generator/TestDefaultInvoiceGenerator.java
index 52a1112..33a14d3 100644
--- a/invoice/src/test/java/org/killbill/billing/invoice/generator/TestDefaultInvoiceGenerator.java
+++ b/invoice/src/test/java/org/killbill/billing/invoice/generator/TestDefaultInvoiceGenerator.java
@@ -106,6 +106,11 @@ public class TestDefaultInvoiceGenerator extends InvoiceTestSuiteNoDB {
             public boolean isEmailNotificationsEnabled() {
                 return false;
             }
+
+            @Override
+            public boolean isInsertZeroUsageItems() {
+                return true;
+            }
         };
         this.generator = new DefaultInvoiceGenerator(clock, null, invoiceConfig, null, controllerDispatcher);
     }

diff --git a/invoice/src/test/java/org/killbill/billing/invoice/usage/TestSubscriptionConsumableInArrear.java b/invoice/src/test/java/org/killbill/billing/invoice/usage/TestSubscriptionConsumableInArrear.java
index c124390..9ab1951 100644
--- a/invoice/src/test/java/org/killbill/billing/invoice/usage/TestSubscriptionConsumableInArrear.java
+++ b/invoice/src/test/java/org/killbill/billing/invoice/usage/TestSubscriptionConsumableInArrear.java
@@ -71,7 +71,7 @@ public class TestSubscriptionConsumableInArrear extends TestUsageInArrearBase {
 
         LocalDate targetDate = new LocalDate(2013, 6, 23);
 
-        final SubscriptionConsumableInArrear foo = new SubscriptionConsumableInArrear(invoiceId, billingEvents, usageUserApi, targetDate, callContext);
+        final SubscriptionConsumableInArrear foo = new SubscriptionConsumableInArrear(invoiceId, billingEvents, usageUserApi, true, targetDate, callContext);
         final List<ContiguousIntervalConsumableInArrear> result = foo.computeInArrearUsageInterval();
         assertEquals(result.size(), 3);
 

diff --git a/invoice/src/test/java/org/killbill/billing/invoice/usage/TestUsageInArrearBase.java b/invoice/src/test/java/org/killbill/billing/invoice/usage/TestUsageInArrearBase.java
index 994fac4..222f938 100644
--- a/invoice/src/test/java/org/killbill/billing/invoice/usage/TestUsageInArrearBase.java
+++ b/invoice/src/test/java/org/killbill/billing/invoice/usage/TestUsageInArrearBase.java
@@ -83,7 +83,7 @@ public abstract class TestUsageInArrearBase extends InvoiceTestSuiteNoDB {
     }
 
     protected ContiguousIntervalConsumableInArrear createContiguousIntervalConsumableInArrear(final DefaultUsage usage, final LocalDate targetDate, final boolean closedInterval, final BillingEvent... events) {
-        final ContiguousIntervalConsumableInArrear intervalConsumableInArrear = new ContiguousIntervalConsumableInArrear(usage, invoiceId, mockUsageUserApi, targetDate, callContext);
+        final ContiguousIntervalConsumableInArrear intervalConsumableInArrear = new ContiguousIntervalConsumableInArrear(usage, invoiceId, mockUsageUserApi, true, targetDate, callContext);
         for (BillingEvent event : events) {
             intervalConsumableInArrear.addBillingEvent(event);
         }

diff --git a/util/src/main/java/org/killbill/billing/util/config/InvoiceConfig.java b/util/src/main/java/org/killbill/billing/util/config/InvoiceConfig.java
index cd71a12..6f8f4bc 100644
--- a/util/src/main/java/org/killbill/billing/util/config/InvoiceConfig.java
+++ b/util/src/main/java/org/killbill/billing/util/config/InvoiceConfig.java
@@ -32,4 +32,9 @@ public interface InvoiceConfig extends KillbillConfig {
     @Description("Whether to send email notifications on invoice creation (for configured accounts)")
     public boolean isEmailNotificationsEnabled();
 
+    @Config("org.killbill.invoice.usage.insert.zero.amount")
+    @Default("true")
+    @Description("Whether to suppress usage items with a zero amount")
+    public boolean isInsertZeroUsageItems();
+
 }