Add command to re-save all environment entities

This is the tool we'll run after dumping everything in sandbox except
for Registrars, Registries, and RegistrarContacts, in order to
re-create the commit logs on said entities.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=119369873

javatests/com/google/domain/registry/tools/ResaveEnvironmentEntitiesCommandTest.java

@@ -0,0 +1,87 @@
+// Copyright 2016 The Domain Registry Authors. All Rights Reserved.
+//
+// Licensed 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
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.domain.registry.tools;
+
+import static com.google.common.collect.Iterables.getOnlyElement;
+import static com.google.common.collect.Iterables.transform;
+import static com.google.common.truth.Truth.assertThat;
+import static com.google.domain.registry.model.ofy.ObjectifyService.ofy;
+import static com.google.domain.registry.testing.DatastoreHelper.createTld;
+
+import com.google.common.base.Function;
+import com.google.domain.registry.model.ImmutableObject;
+import com.google.domain.registry.model.ofy.CommitLogManifest;
+import com.google.domain.registry.model.ofy.CommitLogMutation;
+import com.google.domain.registry.model.registrar.Registrar;
+import com.google.domain.registry.model.registrar.RegistrarContact;
+import com.google.domain.registry.model.registry.Registry;
+
+import org.junit.Test;
+
+/** Unit tests for {@link ResaveEnvironmentEntitiesCommand}. */
+public class ResaveEnvironmentEntitiesCommandTest
+    extends CommandTestCase<ResaveEnvironmentEntitiesCommand> {
+
+  @Test
+  public void testSuccess_noop() throws Exception {
+    // Get rid of all the entities that this command runs on so that it does nothing.
+    deleteEntitiesOfTypes(
+        Registry.class,
+        Registrar.class,
+        RegistrarContact.class,
+        CommitLogManifest.class,
+        CommitLogMutation.class);
+    runCommand();
+    assertThat(ofy().load().type(CommitLogManifest.class).keys()).isEmpty();
+    assertThat(ofy().load().type(CommitLogMutation.class).keys()).isEmpty();
+  }
+
+  @Test
+  public void testSuccess_createsCommitLogs() throws Exception {
+    createTld("tld");
+    deleteEntitiesOfTypes(CommitLogManifest.class, CommitLogMutation.class);
+    assertThat(ofy().load().type(CommitLogManifest.class).keys()).isEmpty();
+    assertThat(ofy().load().type(CommitLogMutation.class).keys()).isEmpty();
+    runCommand();
+
+    // There are five entities that have been re-saved at this point (each in a separate
+    // transaction), so expect five manifests and five mutations.
+    assertThat(ofy().load().type(CommitLogManifest.class).keys()).hasSize(5);
+    Iterable<ImmutableObject> savedEntities =
+        transform(
+            ofy().load().type(CommitLogMutation.class).list(),
+            new Function<CommitLogMutation, ImmutableObject>() {
+              @Override
+              public ImmutableObject apply(CommitLogMutation mutation) {
+                return ofy().load().fromEntity(mutation.getEntity());
+              }
+            });
+    assertThat(savedEntities)
+        .containsExactly(
+            // The Registrars and RegistrarContacts are created by AppEngineRule.
+            Registrar.loadByClientId("TheRegistrar"),
+            Registrar.loadByClientId("NewRegistrar"),
+            Registry.get("tld"),
+            getOnlyElement(Registrar.loadByClientId("TheRegistrar").getContacts()),
+            getOnlyElement(Registrar.loadByClientId("NewRegistrar").getContacts()));
+  }
+
+  @SafeVarargs
+  private static void deleteEntitiesOfTypes(Class<? extends ImmutableObject>... types) {
+    for (Class<? extends ImmutableObject> type : types) {
+      ofy().deleteWithoutBackup().keys(ofy().load().type(type).keys()).now();
+    }
+  }
+}