Streamline transfer resolving helpers in ResourceFlowUtils

In the great flow flattening, ResourceFlowUtils grew a couple nice helpers
for rebuilding transferrable resources (Domains and Contacts) upon the
resolution of a transfer - approvePendingTransfer() and denyPendingTransfer().

Most transfer-resolving callsites use one of these two helpers, but for legacy
reasons the deletion flows (DomainDeleteFlow and DeleteContactsAndHostsAction)
were instead using the "manual" resolvePendingTransfer() method or its even more
low-level createResolvedTransferData() helper instead of denyPendingTransfer().
It's simpler to just have two options - approve and deny - so this CL inlines
createResolvedTransferData() into resolvePendingTransfer() and makes the latter
a private helper for the approve/denyPendingTransfer() public helpers.

This CL also adds sanity checks that approve/denyPendingTransfer() are called
only with the logically appropriate values of TransferStatus.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=170819358

java/google/registry/batch/DeleteContactsAndHostsAction.java

@@ -20,7 +20,7 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
 import static com.google.common.math.IntMath.divide;
 import static com.googlecode.objectify.Key.getKind;
-import static google.registry.flows.ResourceFlowUtils.createResolvedTransferData;
+import static google.registry.flows.ResourceFlowUtils.denyPendingTransfer;
 import static google.registry.flows.ResourceFlowUtils.handlePendingTransferOnDelete;
 import static google.registry.flows.ResourceFlowUtils.updateForeignKeyIndexDeletionTime;
 import static google.registry.flows.async.AsyncFlowEnqueuer.PARAM_CLIENT_TRANSACTION_ID;
@@ -373,12 +373,12 @@ public class DeleteContactsAndHostsAction implements Runnable {
         EppResource.Builder<?, ?> resourceToSaveBuilder;
         if (resource instanceof ContactResource) {
           ContactResource contact = (ContactResource) resource;
-          ContactResource.Builder contactToSaveBuilder = contact.asBuilder();
+          // Handle pending transfers on contact deletion.
           if (contact.getStatusValues().contains(StatusValue.PENDING_TRANSFER)) {
-            contactToSaveBuilder = contactToSaveBuilder.setTransferData(createResolvedTransferData(
-                contact.getTransferData(), TransferStatus.SERVER_CANCELLED, now));
+            contact = denyPendingTransfer(contact, TransferStatus.SERVER_CANCELLED, now);
           }
-          resourceToSaveBuilder = contactToSaveBuilder.wipeOut();
+          // Wipe out PII on contact deletion.
+          resourceToSaveBuilder = contact.asBuilder().wipeOut();
         } else {
           resourceToSaveBuilder = resource.asBuilder();
         }

java/google/registry/flows/ResourceFlowUtils.java

@@ -206,25 +206,6 @@ public final class ResourceFlowUtils {
     }
   }
 
-  /**
-   * Create a {@link TransferData} object representing a resolved transfer.
-   *
-   * <p>This clears all the server-approve fields on the {@link TransferData}, sets the status
-   * field, and sets the expiration time of the last pending transfer to now.
-   */
-  public static TransferData createResolvedTransferData(
-      TransferData oldTransferData, TransferStatus transferStatus, DateTime now) {
-    checkArgument(!oldTransferData.equals(TransferData.EMPTY), "No old transfer to resolve.");
-    return oldTransferData.asBuilder()
-        .setServerApproveEntities(null)
-        .setServerApproveBillingEvent(null)
-        .setServerApproveAutorenewEvent(null)
-        .setServerApproveAutorenewPollMessage(null)
-        .setTransferStatus(transferStatus)
-        .setPendingTransferExpirationTime(checkNotNull(now))
-        .build();
-  }
-
   /**
    * Turn a resource into a builder with its pending transfer resolved.
    *
@@ -232,18 +213,29 @@ public final class ResourceFlowUtils {
    * TransferStatus}, clears all the server-approve fields on the {@link TransferData}, and sets the
    * expiration time of the last pending transfer to now.
    */
-  @SuppressWarnings("unchecked")
-  public static <
+  private static <
           R extends EppResource & ResourceWithTransferData,
           B extends EppResource.Builder<R, B> & BuilderWithTransferData<B>>
       B resolvePendingTransfer(R resource, TransferStatus transferStatus, DateTime now) {
-    checkState(
+    checkArgument(
         resource.getStatusValues().contains(StatusValue.PENDING_TRANSFER),
         "Resource is not in pending transfer status.");
-    return ((B) resource.asBuilder())
+    checkArgument(
+        !TransferData.EMPTY.equals(resource.getTransferData()),
+        "No old transfer data to resolve.");
+    @SuppressWarnings("unchecked")
+    B builder = (B) resource.asBuilder();
+    return builder
         .removeStatusValue(StatusValue.PENDING_TRANSFER)
         .setTransferData(
-            createResolvedTransferData(resource.getTransferData(), transferStatus, now));
+            resource.getTransferData().asBuilder()
+                .setServerApproveEntities(null)
+                .setServerApproveBillingEvent(null)
+                .setServerApproveAutorenewEvent(null)
+                .setServerApproveAutorenewPollMessage(null)
+                .setTransferStatus(transferStatus)
+                .setPendingTransferExpirationTime(checkNotNull(now))
+                .build());
   }
 
   /**
@@ -258,6 +250,7 @@ public final class ResourceFlowUtils {
           R extends EppResource & ResourceWithTransferData,
           B extends Builder<R, B> & BuilderWithTransferData<B>>
       R approvePendingTransfer(R resource, TransferStatus transferStatus, DateTime now) {
+    checkArgument(transferStatus.isApproved(), "Not an approval transfer status");
     B builder = ResourceFlowUtils.<R, B>resolvePendingTransfer(resource, transferStatus, now);
     return builder
         .setLastTransferTime(now)
@@ -274,6 +267,7 @@ public final class ResourceFlowUtils {
    */
   public static <R extends EppResource & ResourceWithTransferData> R denyPendingTransfer(
       R resource, TransferStatus transferStatus, DateTime now) {
+    checkArgument(transferStatus.isDenied(), "Not a denial transfer status");
     return resolvePendingTransfer(resource, transferStatus, now).build();
   }
 

java/google/registry/flows/domain/DomainDeleteFlow.java

@@ -17,6 +17,7 @@ package google.registry.flows.domain;
 import static com.google.common.base.Preconditions.checkNotNull;
 import static google.registry.flows.FlowUtils.persistEntityChanges;
 import static google.registry.flows.FlowUtils.validateClientIsLoggedIn;
+import static google.registry.flows.ResourceFlowUtils.denyPendingTransfer;
 import static google.registry.flows.ResourceFlowUtils.handlePendingTransferOnDelete;
 import static google.registry.flows.ResourceFlowUtils.loadAndVerifyExistence;
 import static google.registry.flows.ResourceFlowUtils.updateForeignKeyIndexDeletionTime;
@@ -48,7 +49,6 @@ import google.registry.flows.ExtensionManager;
 import google.registry.flows.FlowModule.ClientId;
 import google.registry.flows.FlowModule.Superuser;
 import google.registry.flows.FlowModule.TargetId;
-import google.registry.flows.ResourceFlowUtils;
 import google.registry.flows.SessionMetadata;
 import google.registry.flows.TransactionalFlow;
 import google.registry.flows.annotations.ReportingSpec;
@@ -145,10 +145,13 @@ public final class DomainDeleteFlow implements TransactionalFlow {
     customLogic.afterValidation(
         AfterValidationParameters.newBuilder().setExistingDomain(existingDomain).build());
     ImmutableSet.Builder<ImmutableObject> entitiesToSave = new ImmutableSet.Builder<>();
-    Builder builder = existingDomain.getStatusValues().contains(StatusValue.PENDING_TRANSFER)
-        ? ResourceFlowUtils.<DomainResource, DomainResource.Builder>resolvePendingTransfer(
-            existingDomain, TransferStatus.SERVER_CANCELLED, now)
-        : existingDomain.asBuilder();
+    Builder builder;
+    if (existingDomain.getStatusValues().contains(StatusValue.PENDING_TRANSFER)) {
+      builder =
+          denyPendingTransfer(existingDomain, TransferStatus.SERVER_CANCELLED, now).asBuilder();
+    } else {
+      builder = existingDomain.asBuilder();
+    }
     Duration redemptionGracePeriodLength = registry.getRedemptionGracePeriodLength();
     Duration pendingDeleteLength = registry.getPendingDeleteLength();
     DomainDeleteSuperuserExtension domainDeleteSuperuserExtension =

java/google/registry/model/transfer/TransferStatus.java

@@ -54,4 +54,10 @@ public enum TransferStatus {
   public boolean isApproved() {
     return this.equals(CLIENT_APPROVED) || this.equals(SERVER_APPROVED);
   }
+
+  public boolean isDenied() {
+    return this.equals(CLIENT_CANCELLED)
+        || this.equals(CLIENT_REJECTED)
+        || this.equals(SERVER_CANCELLED);
+  }
 }