Add a DAO for RegistryLock objects (#290)

* Add a DAO for RegistryLock objects

* Add an index on verification code and remove old file

* Move to v4

* Use camelCase in index names

* Javadoc fixes

* Allow alteration of RegistryLock objects in-place

* save, load-modify, read in separate transactions

* Change the creation timestamp to be a CreateAutoTimestamp

core/src/test/java/google/registry/model/registry/RegistryLockDaoTest.java

@@ -0,0 +1,104 @@
+// Copyright 2019 The Nomulus 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 google.registry.model.registry;
+
+import static com.google.common.truth.Truth.assertThat;
+import static google.registry.model.transaction.TransactionManagerFactory.jpaTm;
+import static google.registry.testing.JUnitBackports.assertThrows;
+
+import google.registry.model.transaction.JpaTransactionManagerRule;
+import google.registry.schema.domain.RegistryLock;
+import google.registry.schema.domain.RegistryLock.Action;
+import google.registry.testing.AppEngineRule;
+import java.util.UUID;
+import javax.persistence.PersistenceException;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Unit tests for {@link RegistryLockDao}. */
+@RunWith(JUnit4.class)
+public final class RegistryLockDaoTest {
+
+  @Rule public final AppEngineRule appEngine = AppEngineRule.builder().withDatastore().build();
+
+  @Rule
+  public final JpaTransactionManagerRule jpaTmRule =
+      new JpaTransactionManagerRule.Builder().withEntityClass(RegistryLock.class).build();
+
+  @Test
+  public void testSaveAndLoad_success() {
+    RegistryLock lock = createLock();
+    RegistryLockDao.save(lock);
+    RegistryLock fromDatabase = RegistryLockDao.getByVerificationCode(lock.getVerificationCode());
+    assertThat(fromDatabase.getDomainName()).isEqualTo(lock.getDomainName());
+    assertThat(fromDatabase.getVerificationCode()).isEqualTo(lock.getVerificationCode());
+  }
+
+  @Test
+  public void testSaveAndLoad_failure_differentCode() {
+    RegistryLock lock = createLock();
+    RegistryLockDao.save(lock);
+    PersistenceException exception =
+        assertThrows(
+            PersistenceException.class,
+            () -> RegistryLockDao.getByVerificationCode(UUID.randomUUID().toString()));
+    assertThat(exception)
+        .hasCauseThat()
+        .hasMessageThat()
+        .isEqualTo("No registry lock with this code");
+    assertThat(exception).hasCauseThat().isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  public void testSaveTwiceAndLoad_returnsLatest() {
+    RegistryLock lock = createLock();
+    jpaTm().transact(() -> RegistryLockDao.save(lock));
+    jpaTmRule.getTxnClock().advanceOneMilli();
+    jpaTm()
+        .transact(
+            () -> {
+              RegistryLock secondLock =
+                  RegistryLockDao.getByVerificationCode(lock.getVerificationCode());
+              secondLock.setCompletionTimestamp(jpaTmRule.getTxnClock().nowUtc());
+              RegistryLockDao.save(secondLock);
+            });
+    jpaTm()
+        .transact(
+            () -> {
+              RegistryLock fromDatabase =
+                  RegistryLockDao.getByVerificationCode(lock.getVerificationCode());
+              assertThat(fromDatabase.getCompletionTimestamp().get())
+                  .isEqualTo(jpaTmRule.getTxnClock().nowUtc());
+            });
+  }
+
+  @Test
+  public void testFailure_saveNull() {
+    assertThrows(NullPointerException.class, () -> RegistryLockDao.save(null));
+  }
+
+  private RegistryLock createLock() {
+    return new RegistryLock.Builder()
+        .setRepoId("repoId")
+        .setDomainName("example.test")
+        .setRegistrarId("TheRegistrar")
+        .setAction(Action.LOCK)
+        .setVerificationCode(UUID.randomUUID().toString())
+        .isSuperuser(true)
+        .build();
+  }
+}