javatests/com/google/gerrit/acceptance/rest/change/ChangeMessagesIT.java - gerrit.git - Git at Google

 // Copyright (C) 2013 The Android Open Source Project
 //
 // 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.gerrit.acceptance.rest.change;

 import static com.google.common.truth.Truth.assertThat;
 import static com.google.common.truth.Truth.assertWithMessage;
 import static com.google.common.truth.Truth8.assertThat;
 import static com.google.gerrit.acceptance.PushOneCommit.FILE_NAME;
 import static com.google.gerrit.acceptance.testsuite.project.TestProjectUpdate.allowCapability;
 import static com.google.gerrit.extensions.client.ListChangesOption.DETAILED_ACCOUNTS;
 import static com.google.gerrit.extensions.client.ListChangesOption.MESSAGES;
 import static com.google.gerrit.server.group.SystemGroupBackend.REGISTERED_USERS;
 import static com.google.gerrit.server.notedb.ChangeNoteUtil.parseCommitMessageRange;
 import static com.google.gerrit.testing.GerritJUnit.assertThrows;
 import static java.util.stream.Collectors.toSet;
 import static org.eclipse.jgit.util.RawParseUtils.decode;

 import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
 import com.google.gerrit.acceptance.AbstractDaemonTest;
 import com.google.gerrit.acceptance.PushOneCommit;
 import com.google.gerrit.acceptance.TestAccount;
 import com.google.gerrit.acceptance.UseClockStep;
 import com.google.gerrit.acceptance.UseTimezone;
 import com.google.gerrit.acceptance.testsuite.project.ProjectOperations;
 import com.google.gerrit.acceptance.testsuite.request.RequestScopeOperations;
 import com.google.gerrit.common.data.GlobalCapability;
 import com.google.gerrit.entities.Change;
 import com.google.gerrit.entities.LabelId;
 import com.google.gerrit.extensions.api.changes.DeleteChangeMessageInput;
 import com.google.gerrit.extensions.api.changes.ReviewInput;
 import com.google.gerrit.extensions.common.ChangeInfo;
 import com.google.gerrit.extensions.common.ChangeMessageInfo;
 import com.google.gerrit.extensions.common.CommentInfo;
 import com.google.gerrit.extensions.restapi.AuthException;
 import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
 import com.google.gerrit.server.notedb.ChangeNoteUtil;
 import com.google.gerrit.server.util.AccountTemplateUtil;
 import com.google.inject.Inject;
 import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Optional;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.util.RawParseUtils;
 import org.junit.Test;

 @UseClockStep
 @UseTimezone(timezone = "US/Eastern")
 public class ChangeMessagesIT extends AbstractDaemonTest {
   @Inject private ProjectOperations projectOperations;
   @Inject private RequestScopeOperations requestScopeOperations;

   @Test
   public void messagesNotReturnedByDefault() throws Exception {
     String changeId = createChange().getChangeId();
     postMessage(changeId, "Some nits need to be fixed.");
     ChangeInfo c = info(changeId);
     assertThat(c.messages).isNull();
   }

   @Test
   public void defaultMessage() throws Exception {
     String changeId = createChange().getChangeId();
     ChangeInfo c = get(changeId, MESSAGES);
     assertThat(c.messages).isNotNull();
     assertThat(c.messages).hasSize(1);
     assertThat(c.messages.iterator().next().message).isEqualTo("Uploaded patch set 1.");
   }

   @Test
   public void messageWithAccountTemplate() throws Exception {
     String changeId = createChange().getChangeId();
     String messageTemplate =
         String.format(
             "Review added by %s: some nits need to be fixed by %s.",
             AccountTemplateUtil.getAccountTemplate(admin.id()),
             AccountTemplateUtil.getAccountTemplate(user.id()));
     postMessage(changeId, messageTemplate);
     ChangeInfo c = get(changeId, MESSAGES, DETAILED_ACCOUNTS);
     assertThat(c.messages).isNotNull();
     assertThat(c.messages).hasSize(2);
     Iterator<ChangeMessageInfo> it = c.messages.iterator();
     ChangeMessageInfo defaultMessage = it.next();
     assertThat(defaultMessage.message).isEqualTo("Uploaded patch set 1.");
     assertThat(defaultMessage.accountsInMessage).isEmpty();
     ChangeMessageInfo messageWithTemplate = it.next();
     assertMessage(messageTemplate, messageWithTemplate.message);
     assertThat(messageWithTemplate.accountsInMessage)
         .containsExactly(getAccountInfo(admin.id()), getAccountInfo(user.id()));
   }

   @Test
   public void messagesReturnedInChronologicalOrder() throws Exception {
     String changeId = createChange().getChangeId();
     String firstMessage = "Some nits need to be fixed.";
     postMessage(changeId, firstMessage);
     String secondMessage = "I like this feature.";
     postMessage(changeId, secondMessage);
     ChangeInfo c = get(changeId, MESSAGES);
     assertThat(c.messages).isNotNull();
     assertThat(c.messages).hasSize(3);
     Iterator<ChangeMessageInfo> it = c.messages.iterator();
     assertThat(it.next().message).isEqualTo("Uploaded patch set 1.");
     assertMessage(firstMessage, it.next().message);
     assertMessage(secondMessage, it.next().message);
   }

   @Test
   public void postMessageWithTag() throws Exception {
     String changeId = createChange().getChangeId();
     String tag = "jenkins";
     String msg = "Message with tag.";
     postMessage(changeId, msg, tag);
     ChangeInfo c = get(changeId, MESSAGES);
     assertThat(c.messages).isNotNull();
     assertThat(c.messages).hasSize(2);
     Iterator<ChangeMessageInfo> it = c.messages.iterator();
     assertThat(it.next().message).isEqualTo("Uploaded patch set 1.");
     ChangeMessageInfo actual = it.next();
     assertMessage(msg, actual.message);
     assertThat(actual.tag).isEqualTo(tag);
   }

   @Test
   public void listChangeMessages() throws Exception {
     int changeNum = createOneChangeWithMultipleChangeMessagesInHistory();
     List<ChangeMessageInfo> messages1 = gApi.changes().id(changeNum).messages();
     List<ChangeMessageInfo> messages2 =
         new ArrayList<>(gApi.changes().id(changeNum).get().messages);
     assertThat(messages1).containsExactlyElementsIn(messages2).inOrder();
   }

   @Test
   public void listChangeMessagesSkippedEmpty() throws Exception {
     // Change message 1: create a change.
     PushOneCommit.Result result = createChange();
     String changeId = result.getChangeId();
     // Will be a new commit with empty change message on the meta branch.
     addOneReviewWithEmptyChangeMessage(changeId);
     // Change Message 2: post a review with message "message 1".
     addOneReview(changeId, "message");

     List<ChangeMessageInfo> messages = gApi.changes().id(changeId).messages();
     assertThat(messages).hasSize(2);
   }

   @Test
   public void getOneChangeMessage() throws Exception {
     int changeNum = createOneChangeWithMultipleChangeMessagesInHistory();
     List<ChangeMessageInfo> messages = new ArrayList<>(gApi.changes().id(changeNum).get().messages);
     for (ChangeMessageInfo messageInfo : messages) {
       String id = messageInfo.id;
       assertThat(gApi.changes().id(changeNum).message(id).get()).isEqualTo(messageInfo);
     }
   }

   @Test
   public void getChangeMessagesWithTemplate() throws Exception {
     String changeId = createChange().getChangeId();
     String messageTemplate = "Review by " + AccountTemplateUtil.getAccountTemplate(admin.id());
     postMessage(changeId, messageTemplate);
     assertMessage(
         messageTemplate,
         Iterables.getLast(gApi.changes().id(changeId).get(MESSAGES).messages).message);

     Collection<ChangeMessageInfo> listMessages = gApi.changes().id(changeId).messages();
     assertThat(listMessages).hasSize(2);
     ChangeMessageInfo changeMessageApi = Iterables.getLast(gApi.changes().id(changeId).messages());
     assertMessage("Review by " + admin.getNameEmail(), changeMessageApi.message);
     assertMessage(
         "Review by " + admin.getNameEmail(),
         gApi.changes().id(changeId).message(changeMessageApi.id).get().message);
     DeleteChangeMessageInput input = new DeleteChangeMessageInput("message deleted");
     assertThat(gApi.changes().id(changeId).message(changeMessageApi.id).delete(input).message)
         .isEqualTo(
             String.format(
                 "Change message removed by: %s\nReason: message deleted", admin.getNameEmail()));
   }

   @Test
   public void deleteCannotBeAppliedWithoutAdministrateServerCapability() throws Exception {
     int changeNum = createOneChangeWithMultipleChangeMessagesInHistory();
     requestScopeOperations.setApiUser(user.id());

     AuthException thrown =
         assertThrows(AuthException.class, () -> deleteOneChangeMessage(changeNum, 0, user, "spam"));
     assertThat(thrown).hasMessageThat().isEqualTo("administrate server not permitted");
   }

   @Test
   public void deleteCanBeAppliedWithAdministrateServerCapability() throws Exception {
     projectOperations
         .allProjectsForUpdate()
         .add(allowCapability(GlobalCapability.ADMINISTRATE_SERVER).group(REGISTERED_USERS))
         .update();
     int changeNum = createOneChangeWithMultipleChangeMessagesInHistory();
     requestScopeOperations.setApiUser(user.id());
     deleteOneChangeMessage(changeNum, 0, user, "spam");
   }

   @Test
   public void deleteCannotBeAppliedWithEmptyChangeMessageUuid() throws Exception {
     String changeId = createChange().getChangeId();

     ResourceNotFoundException thrown =
         assertThrows(
             ResourceNotFoundException.class,
             () ->
                 gApi.changes()
                     .id(changeId)
                     .message("")
                     .delete(new DeleteChangeMessageInput("spam")));
     assertThat(thrown).hasMessageThat().isEqualTo("change message  not found");
   }

   @Test
   public void deleteCannotBeAppliedWithNonExistingChangeMessageUuid() throws Exception {
     String changeId = createChange().getChangeId();
     DeleteChangeMessageInput input = new DeleteChangeMessageInput();
     String id = "8473b95934b5732ac55d26311a706c9c2bde9941";
     input.reason = "spam";

     ResourceNotFoundException thrown =
         assertThrows(
             ResourceNotFoundException.class,
             () -> gApi.changes().id(changeId).message(id).delete(input));
     assertThat(thrown).hasMessageThat().isEqualTo(String.format("change message %s not found", id));
   }

   @Test
   public void deleteCanBeAppliedWithoutProvidingReason() throws Exception {
     int changeNum = createOneChangeWithMultipleChangeMessagesInHistory();
     deleteOneChangeMessage(changeNum, 2, admin, "");
   }

   @Test
   public void deleteOneChangeMessageTwice() throws Exception {
     int changeNum = createOneChangeWithMultipleChangeMessagesInHistory();
     // Deletes the second change message twice.
     deleteOneChangeMessage(changeNum, 1, admin, "reason 1");
     deleteOneChangeMessage(changeNum, 1, admin, "reason 2");
   }

   @Test
   public void deleteMultipleChangeMessages() throws Exception {
     int changeNum = createOneChangeWithMultipleChangeMessagesInHistory();
     for (int i = 0; i < 7; ++i) {
       deleteOneChangeMessage(changeNum, i, admin, "reason " + i);
     }
   }

   private int createOneChangeWithMultipleChangeMessagesInHistory() throws Exception {
     // Creates the following commit history on the meta branch of the test change.

     requestScopeOperations.setApiUser(user.id());
     // Commit 1: create a change.
     PushOneCommit.Result result = createChange();
     String changeId = result.getChangeId();
     // Commit 2: post an empty change message.
     requestScopeOperations.setApiUser(admin.id());
     addOneReviewWithEmptyChangeMessage(changeId);
     // Commit 3: post a review with message "message 1".
     addOneReview(changeId, "message 1");
     // Commit 4: amend a new patch set.
     requestScopeOperations.setApiUser(user.id());
     amendChange(changeId);
     // Commit 5: post a review with message "message 2".
     addOneReview(changeId, "message 2");
     // Commit 6: amend a new patch set.
     amendChange(changeId);
     // Commit 7: approve the change.
     requestScopeOperations.setApiUser(admin.id());
     gApi.changes().id(changeId).current().review(ReviewInput.approve());
     // commit 8: submit the change.
     gApi.changes().id(changeId).current().submit();

     // Verifies there is only 7 change messages although there are 8 commits.
     List<ChangeMessageInfo> messages = gApi.changes().id(changeId).messages();
     assertThat(messages).hasSize(7);

     return result.getChange().getId().get();
   }

   private void addOneReview(String changeId, String changeMessage) throws Exception {
     ReviewInput.CommentInput c = new ReviewInput.CommentInput();
     c.line = 1;
     c.message = "comment 1";
     c.path = FILE_NAME;

     ReviewInput reviewInput = new ReviewInput().label(LabelId.CODE_REVIEW, 1);
     reviewInput.comments = ImmutableMap.of(c.path, Lists.newArrayList(c));
     reviewInput.message = changeMessage;

     gApi.changes().id(changeId).current().review(reviewInput);
   }

   private void addOneReviewWithEmptyChangeMessage(String changeId) throws Exception {
     gApi.changes().id(changeId).current().review(new ReviewInput());
   }

   private void deleteOneChangeMessage(
       int changeNum, int deletedMessageIndex, TestAccount deletedBy, String reason)
       throws Exception {
     List<ChangeMessageInfo> messagesBeforeDeletion = gApi.changes().id(changeNum).messages();

     List<CommentInfo> commentsBefore = getChangeSortedComments(changeNum);
     List<RevCommit> commitsBefore = getChangeMetaCommitsInReverseOrder(Change.id(changeNum));

     String id = messagesBeforeDeletion.get(deletedMessageIndex).id;
     DeleteChangeMessageInput input = new DeleteChangeMessageInput(reason);
     ChangeMessageInfo info = gApi.changes().id(changeNum).message(id).delete(input);

     // Verify the return change message info is as expect.
     String expectedMessage = "Change message removed by: " + deletedBy.getNameEmail();
     if (!Strings.isNullOrEmpty(reason)) {
       expectedMessage = expectedMessage + "\nReason: " + reason;
     }
     assertThat(info.message).isEqualTo(expectedMessage);
     List<ChangeMessageInfo> messagesAfterDeletion = gApi.changes().id(changeNum).messages();
     assertMessagesAfterDeletion(
         messagesBeforeDeletion, messagesAfterDeletion, deletedMessageIndex, expectedMessage);
     assertCommentsAfterDeletion(changeNum, commentsBefore);

     // Verify change index is updated after deletion.
     List<ChangeInfo> changes = gApi.changes().query("message removed").get();
     assertThat(changes.stream().map(c -> c._number).collect(toSet())).contains(changeNum);

     // Verifies states of commits.
     assertMetaCommitsAfterDeletion(commitsBefore, changeNum, id, deletedBy, reason);
   }

   private void assertMessagesAfterDeletion(
       List<ChangeMessageInfo> messagesBeforeDeletion,
       List<ChangeMessageInfo> messagesAfterDeletion,
       int deletedMessageIndex,
       String expectedDeleteMessage) {
     assertWithMessage("after: %s; before: %s", messagesAfterDeletion, messagesBeforeDeletion)
         .that(messagesAfterDeletion)
         .hasSize(messagesBeforeDeletion.size());

     for (int i = 0; i < messagesAfterDeletion.size(); ++i) {
       ChangeMessageInfo before = messagesBeforeDeletion.get(i);
       ChangeMessageInfo after = messagesAfterDeletion.get(i);

       if (i < deletedMessageIndex) {
         // The uuid of a commit message will be updated after rewriting.
         assertThat(after.id).isEqualTo(before.id);
       }

       assertThat(after.tag).isEqualTo(before.tag);
       assertThat(after.author).isEqualTo(before.author);
       assertThat(after.realAuthor).isEqualTo(before.realAuthor);
       assertThat(after._revisionNumber).isEqualTo(before._revisionNumber);

       if (i == deletedMessageIndex) {
         assertThat(after.message).isEqualTo(expectedDeleteMessage);
       } else {
         assertThat(after.message).isEqualTo(before.message);
       }
     }
   }

   private void assertMetaCommitsAfterDeletion(
       List<RevCommit> commitsBeforeDeletion,
       int changeNum,
       String deletedMessageId,
       TestAccount deletedBy,
       String deleteReason)
       throws Exception {
     List<RevCommit> commitsAfterDeletion = getChangeMetaCommitsInReverseOrder(Change.id(changeNum));
     assertThat(commitsAfterDeletion).hasSize(commitsBeforeDeletion.size());

     for (int i = 0; i < commitsBeforeDeletion.size(); i++) {
       RevCommit commitBefore = commitsBeforeDeletion.get(i);
       RevCommit commitAfter = commitsAfterDeletion.get(i);
       if (commitBefore.getId().getName().equals(deletedMessageId)) {
         byte[] rawBefore = commitBefore.getRawBuffer();
         byte[] rawAfter = commitAfter.getRawBuffer();
         Charset encodingBefore = RawParseUtils.parseEncoding(rawBefore);
         Charset encodingAfter = RawParseUtils.parseEncoding(rawAfter);
         Optional<ChangeNoteUtil.CommitMessageRange> rangeBefore =
             parseCommitMessageRange(commitBefore);
         Optional<ChangeNoteUtil.CommitMessageRange> rangeAfter =
             parseCommitMessageRange(commitAfter);
         assertThat(rangeBefore).isPresent();
         assertThat(rangeAfter).isPresent();

         String subjectBefore =
             decode(
                 encodingBefore,
                 rawBefore,
                 rangeBefore.get().subjectStart(),
                 rangeBefore.get().subjectEnd());
         String subjectAfter =
             decode(
                 encodingAfter,
                 rawAfter,
                 rangeAfter.get().subjectStart(),
                 rangeAfter.get().subjectEnd());
         assertThat(subjectBefore).isEqualTo(subjectAfter);

         String footersBefore =
             decode(
                 encodingBefore,
                 rawBefore,
                 rangeBefore.get().changeMessageEnd() + 1,
                 rawBefore.length);
         String footersAfter =
             decode(
                 encodingAfter, rawAfter, rangeAfter.get().changeMessageEnd() + 1, rawAfter.length);
         assertThat(footersBefore).isEqualTo(footersAfter);

         String message =
             decode(
                 encodingAfter,
                 rawAfter,
                 rangeAfter.get().changeMessageStart(),
                 rangeAfter.get().changeMessageEnd() + 1);
         String expectedMessageTemplate =
             "Change message removed by: " + AccountTemplateUtil.getAccountTemplate(deletedBy.id());
         if (!Strings.isNullOrEmpty(deleteReason)) {
           expectedMessageTemplate = expectedMessageTemplate + "\nReason: " + deleteReason;
         }
         assertThat(message).isEqualTo(expectedMessageTemplate);
       } else {
         assertThat(commitAfter.getFullMessage()).isEqualTo(commitBefore.getFullMessage());
       }

       assertThat(commitAfter.getCommitterIdent().getName())
           .isEqualTo(commitBefore.getCommitterIdent().getName());
       assertThat(commitAfter.getAuthorIdent().getName())
           .isEqualTo(commitBefore.getAuthorIdent().getName());
       assertThat(commitAfter.getEncoding()).isEqualTo(commitBefore.getEncoding());
       assertThat(commitAfter.getEncodingName()).isEqualTo(commitBefore.getEncodingName());
     }
   }

   /** Verifies comments are not changed after deleting change message(s). */
   private void assertCommentsAfterDeletion(int changeNum, List<CommentInfo> commentsBeforeDeletion)
       throws Exception {
     List<CommentInfo> commentsAfterDeletion = getChangeSortedComments(changeNum);
     assertThat(commentsAfterDeletion).containsExactlyElementsIn(commentsBeforeDeletion).inOrder();
   }

   private static void assertMessage(String expected, String actual) {
     assertThat(actual).isEqualTo("Patch Set 1:\n\n" + expected);
   }

   private void postMessage(String changeId, String msg) throws Exception {
     postMessage(changeId, msg, null);
   }

   private void postMessage(String changeId, String msg, String tag) throws Exception {
     ReviewInput in = new ReviewInput();
     in.message = msg;
     in.tag = tag;
     gApi.changes().id(changeId).current().review(in);
   }
 }
	// Copyright (C) 2013 The Android Open Source Project
	//
	// 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.gerrit.acceptance.rest.change;

	import static com.google.common.truth.Truth.assertThat;
	import static com.google.common.truth.Truth.assertWithMessage;
	import static com.google.common.truth.Truth8.assertThat;
	import static com.google.gerrit.acceptance.PushOneCommit.FILE_NAME;
	import static com.google.gerrit.acceptance.testsuite.project.TestProjectUpdate.allowCapability;
	import static com.google.gerrit.extensions.client.ListChangesOption.DETAILED_ACCOUNTS;
	import static com.google.gerrit.extensions.client.ListChangesOption.MESSAGES;
	import static com.google.gerrit.server.group.SystemGroupBackend.REGISTERED_USERS;
	import static com.google.gerrit.server.notedb.ChangeNoteUtil.parseCommitMessageRange;
	import static com.google.gerrit.testing.GerritJUnit.assertThrows;
	import static java.util.stream.Collectors.toSet;
	import static org.eclipse.jgit.util.RawParseUtils.decode;

	import com.google.common.base.Strings;
	import com.google.common.collect.ImmutableMap;
	import com.google.common.collect.Iterables;
	import com.google.common.collect.Lists;
	import com.google.gerrit.acceptance.AbstractDaemonTest;
	import com.google.gerrit.acceptance.PushOneCommit;
	import com.google.gerrit.acceptance.TestAccount;
	import com.google.gerrit.acceptance.UseClockStep;
	import com.google.gerrit.acceptance.UseTimezone;
	import com.google.gerrit.acceptance.testsuite.project.ProjectOperations;
	import com.google.gerrit.acceptance.testsuite.request.RequestScopeOperations;
	import com.google.gerrit.common.data.GlobalCapability;
	import com.google.gerrit.entities.Change;
	import com.google.gerrit.entities.LabelId;
	import com.google.gerrit.extensions.api.changes.DeleteChangeMessageInput;
	import com.google.gerrit.extensions.api.changes.ReviewInput;
	import com.google.gerrit.extensions.common.ChangeInfo;
	import com.google.gerrit.extensions.common.ChangeMessageInfo;
	import com.google.gerrit.extensions.common.CommentInfo;
	import com.google.gerrit.extensions.restapi.AuthException;
	import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
	import com.google.gerrit.server.notedb.ChangeNoteUtil;
	import com.google.gerrit.server.util.AccountTemplateUtil;
	import com.google.inject.Inject;
	import java.nio.charset.Charset;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.Iterator;
	import java.util.List;
	import java.util.Optional;
	import org.eclipse.jgit.revwalk.RevCommit;
	import org.eclipse.jgit.util.RawParseUtils;
	import org.junit.Test;

	@UseClockStep
	@UseTimezone(timezone = "US/Eastern")
	public class ChangeMessagesIT extends AbstractDaemonTest {
	@Inject private ProjectOperations projectOperations;
	@Inject private RequestScopeOperations requestScopeOperations;

	@Test
	public void messagesNotReturnedByDefault() throws Exception {
	String changeId = createChange().getChangeId();
	postMessage(changeId, "Some nits need to be fixed.");
	ChangeInfo c = info(changeId);
	assertThat(c.messages).isNull();
	}

	@Test
	public void defaultMessage() throws Exception {
	String changeId = createChange().getChangeId();
	ChangeInfo c = get(changeId, MESSAGES);
	assertThat(c.messages).isNotNull();
	assertThat(c.messages).hasSize(1);
	assertThat(c.messages.iterator().next().message).isEqualTo("Uploaded patch set 1.");
	}

	@Test
	public void messageWithAccountTemplate() throws Exception {
	String changeId = createChange().getChangeId();
	String messageTemplate =
	String.format(
	"Review added by %s: some nits need to be fixed by %s.",
	AccountTemplateUtil.getAccountTemplate(admin.id()),
	AccountTemplateUtil.getAccountTemplate(user.id()));
	postMessage(changeId, messageTemplate);
	ChangeInfo c = get(changeId, MESSAGES, DETAILED_ACCOUNTS);
	assertThat(c.messages).isNotNull();
	assertThat(c.messages).hasSize(2);
	Iterator<ChangeMessageInfo> it = c.messages.iterator();
	ChangeMessageInfo defaultMessage = it.next();
	assertThat(defaultMessage.message).isEqualTo("Uploaded patch set 1.");
	assertThat(defaultMessage.accountsInMessage).isEmpty();
	ChangeMessageInfo messageWithTemplate = it.next();
	assertMessage(messageTemplate, messageWithTemplate.message);
	assertThat(messageWithTemplate.accountsInMessage)
	.containsExactly(getAccountInfo(admin.id()), getAccountInfo(user.id()));
	}

	@Test
	public void messagesReturnedInChronologicalOrder() throws Exception {
	String changeId = createChange().getChangeId();
	String firstMessage = "Some nits need to be fixed.";
	postMessage(changeId, firstMessage);
	String secondMessage = "I like this feature.";
	postMessage(changeId, secondMessage);
	ChangeInfo c = get(changeId, MESSAGES);
	assertThat(c.messages).isNotNull();
	assertThat(c.messages).hasSize(3);
	Iterator<ChangeMessageInfo> it = c.messages.iterator();
	assertThat(it.next().message).isEqualTo("Uploaded patch set 1.");
	assertMessage(firstMessage, it.next().message);
	assertMessage(secondMessage, it.next().message);
	}

	@Test
	public void postMessageWithTag() throws Exception {
	String changeId = createChange().getChangeId();
	String tag = "jenkins";
	String msg = "Message with tag.";
	postMessage(changeId, msg, tag);
	ChangeInfo c = get(changeId, MESSAGES);
	assertThat(c.messages).isNotNull();
	assertThat(c.messages).hasSize(2);
	Iterator<ChangeMessageInfo> it = c.messages.iterator();
	assertThat(it.next().message).isEqualTo("Uploaded patch set 1.");
	ChangeMessageInfo actual = it.next();
	assertMessage(msg, actual.message);
	assertThat(actual.tag).isEqualTo(tag);
	}

	@Test
	public void listChangeMessages() throws Exception {
	int changeNum = createOneChangeWithMultipleChangeMessagesInHistory();
	List<ChangeMessageInfo> messages1 = gApi.changes().id(changeNum).messages();
	List<ChangeMessageInfo> messages2 =
	new ArrayList<>(gApi.changes().id(changeNum).get().messages);
	assertThat(messages1).containsExactlyElementsIn(messages2).inOrder();
	}

	@Test
	public void listChangeMessagesSkippedEmpty() throws Exception {
	// Change message 1: create a change.
	PushOneCommit.Result result = createChange();
	String changeId = result.getChangeId();
	// Will be a new commit with empty change message on the meta branch.
	addOneReviewWithEmptyChangeMessage(changeId);
	// Change Message 2: post a review with message "message 1".
	addOneReview(changeId, "message");

	List<ChangeMessageInfo> messages = gApi.changes().id(changeId).messages();
	assertThat(messages).hasSize(2);
	}

	@Test
	public void getOneChangeMessage() throws Exception {
	int changeNum = createOneChangeWithMultipleChangeMessagesInHistory();
	List<ChangeMessageInfo> messages = new ArrayList<>(gApi.changes().id(changeNum).get().messages);
	for (ChangeMessageInfo messageInfo : messages) {
	String id = messageInfo.id;
	assertThat(gApi.changes().id(changeNum).message(id).get()).isEqualTo(messageInfo);
	}
	}

	@Test
	public void getChangeMessagesWithTemplate() throws Exception {
	String changeId = createChange().getChangeId();
	String messageTemplate = "Review by " + AccountTemplateUtil.getAccountTemplate(admin.id());
	postMessage(changeId, messageTemplate);
	assertMessage(
	messageTemplate,
	Iterables.getLast(gApi.changes().id(changeId).get(MESSAGES).messages).message);

	Collection<ChangeMessageInfo> listMessages = gApi.changes().id(changeId).messages();
	assertThat(listMessages).hasSize(2);
	ChangeMessageInfo changeMessageApi = Iterables.getLast(gApi.changes().id(changeId).messages());
	assertMessage("Review by " + admin.getNameEmail(), changeMessageApi.message);
	assertMessage(
	"Review by " + admin.getNameEmail(),
	gApi.changes().id(changeId).message(changeMessageApi.id).get().message);
	DeleteChangeMessageInput input = new DeleteChangeMessageInput("message deleted");
	assertThat(gApi.changes().id(changeId).message(changeMessageApi.id).delete(input).message)
	.isEqualTo(
	String.format(
	"Change message removed by: %s\nReason: message deleted", admin.getNameEmail()));
	}

	@Test
	public void deleteCannotBeAppliedWithoutAdministrateServerCapability() throws Exception {
	int changeNum = createOneChangeWithMultipleChangeMessagesInHistory();
	requestScopeOperations.setApiUser(user.id());

	AuthException thrown =
	assertThrows(AuthException.class, () -> deleteOneChangeMessage(changeNum, 0, user, "spam"));
	assertThat(thrown).hasMessageThat().isEqualTo("administrate server not permitted");
	}

	@Test
	public void deleteCanBeAppliedWithAdministrateServerCapability() throws Exception {
	projectOperations
	.allProjectsForUpdate()
	.add(allowCapability(GlobalCapability.ADMINISTRATE_SERVER).group(REGISTERED_USERS))
	.update();
	int changeNum = createOneChangeWithMultipleChangeMessagesInHistory();
	requestScopeOperations.setApiUser(user.id());
	deleteOneChangeMessage(changeNum, 0, user, "spam");
	}

	@Test
	public void deleteCannotBeAppliedWithEmptyChangeMessageUuid() throws Exception {
	String changeId = createChange().getChangeId();

	ResourceNotFoundException thrown =
	assertThrows(
	ResourceNotFoundException.class,
	() ->
	gApi.changes()
	.id(changeId)
	.message("")
	.delete(new DeleteChangeMessageInput("spam")));
	assertThat(thrown).hasMessageThat().isEqualTo("change message not found");
	}

	@Test
	public void deleteCannotBeAppliedWithNonExistingChangeMessageUuid() throws Exception {
	String changeId = createChange().getChangeId();
	DeleteChangeMessageInput input = new DeleteChangeMessageInput();
	String id = "8473b95934b5732ac55d26311a706c9c2bde9941";
	input.reason = "spam";

	ResourceNotFoundException thrown =
	assertThrows(
	ResourceNotFoundException.class,
	() -> gApi.changes().id(changeId).message(id).delete(input));
	assertThat(thrown).hasMessageThat().isEqualTo(String.format("change message %s not found", id));
	}

	@Test
	public void deleteCanBeAppliedWithoutProvidingReason() throws Exception {
	int changeNum = createOneChangeWithMultipleChangeMessagesInHistory();
	deleteOneChangeMessage(changeNum, 2, admin, "");
	}

	@Test
	public void deleteOneChangeMessageTwice() throws Exception {
	int changeNum = createOneChangeWithMultipleChangeMessagesInHistory();
	// Deletes the second change message twice.
	deleteOneChangeMessage(changeNum, 1, admin, "reason 1");
	deleteOneChangeMessage(changeNum, 1, admin, "reason 2");
	}

	@Test
	public void deleteMultipleChangeMessages() throws Exception {
	int changeNum = createOneChangeWithMultipleChangeMessagesInHistory();
	for (int i = 0; i < 7; ++i) {
	deleteOneChangeMessage(changeNum, i, admin, "reason " + i);
	}
	}

	private int createOneChangeWithMultipleChangeMessagesInHistory() throws Exception {
	// Creates the following commit history on the meta branch of the test change.

	requestScopeOperations.setApiUser(user.id());
	// Commit 1: create a change.
	PushOneCommit.Result result = createChange();
	String changeId = result.getChangeId();
	// Commit 2: post an empty change message.
	requestScopeOperations.setApiUser(admin.id());
	addOneReviewWithEmptyChangeMessage(changeId);
	// Commit 3: post a review with message "message 1".
	addOneReview(changeId, "message 1");
	// Commit 4: amend a new patch set.
	requestScopeOperations.setApiUser(user.id());
	amendChange(changeId);
	// Commit 5: post a review with message "message 2".
	addOneReview(changeId, "message 2");
	// Commit 6: amend a new patch set.
	amendChange(changeId);
	// Commit 7: approve the change.
	requestScopeOperations.setApiUser(admin.id());
	gApi.changes().id(changeId).current().review(ReviewInput.approve());
	// commit 8: submit the change.
	gApi.changes().id(changeId).current().submit();

	// Verifies there is only 7 change messages although there are 8 commits.
	List<ChangeMessageInfo> messages = gApi.changes().id(changeId).messages();
	assertThat(messages).hasSize(7);

	return result.getChange().getId().get();
	}

	private void addOneReview(String changeId, String changeMessage) throws Exception {
	ReviewInput.CommentInput c = new ReviewInput.CommentInput();
	c.line = 1;
	c.message = "comment 1";
	c.path = FILE_NAME;

	ReviewInput reviewInput = new ReviewInput().label(LabelId.CODE_REVIEW, 1);
	reviewInput.comments = ImmutableMap.of(c.path, Lists.newArrayList(c));
	reviewInput.message = changeMessage;

	gApi.changes().id(changeId).current().review(reviewInput);
	}

	private void addOneReviewWithEmptyChangeMessage(String changeId) throws Exception {
	gApi.changes().id(changeId).current().review(new ReviewInput());
	}

	private void deleteOneChangeMessage(
	int changeNum, int deletedMessageIndex, TestAccount deletedBy, String reason)
	throws Exception {
	List<ChangeMessageInfo> messagesBeforeDeletion = gApi.changes().id(changeNum).messages();

	List<CommentInfo> commentsBefore = getChangeSortedComments(changeNum);
	List<RevCommit> commitsBefore = getChangeMetaCommitsInReverseOrder(Change.id(changeNum));

	String id = messagesBeforeDeletion.get(deletedMessageIndex).id;
	DeleteChangeMessageInput input = new DeleteChangeMessageInput(reason);
	ChangeMessageInfo info = gApi.changes().id(changeNum).message(id).delete(input);

	// Verify the return change message info is as expect.
	String expectedMessage = "Change message removed by: " + deletedBy.getNameEmail();
	if (!Strings.isNullOrEmpty(reason)) {
	expectedMessage = expectedMessage + "\nReason: " + reason;
	}
	assertThat(info.message).isEqualTo(expectedMessage);
	List<ChangeMessageInfo> messagesAfterDeletion = gApi.changes().id(changeNum).messages();
	assertMessagesAfterDeletion(
	messagesBeforeDeletion, messagesAfterDeletion, deletedMessageIndex, expectedMessage);
	assertCommentsAfterDeletion(changeNum, commentsBefore);

	// Verify change index is updated after deletion.
	List<ChangeInfo> changes = gApi.changes().query("message removed").get();
	assertThat(changes.stream().map(c -> c._number).collect(toSet())).contains(changeNum);

	// Verifies states of commits.
	assertMetaCommitsAfterDeletion(commitsBefore, changeNum, id, deletedBy, reason);
	}

	private void assertMessagesAfterDeletion(
	List<ChangeMessageInfo> messagesBeforeDeletion,
	List<ChangeMessageInfo> messagesAfterDeletion,
	int deletedMessageIndex,
	String expectedDeleteMessage) {
	assertWithMessage("after: %s; before: %s", messagesAfterDeletion, messagesBeforeDeletion)
	.that(messagesAfterDeletion)
	.hasSize(messagesBeforeDeletion.size());

	for (int i = 0; i < messagesAfterDeletion.size(); ++i) {
	ChangeMessageInfo before = messagesBeforeDeletion.get(i);
	ChangeMessageInfo after = messagesAfterDeletion.get(i);

	if (i < deletedMessageIndex) {
	// The uuid of a commit message will be updated after rewriting.
	assertThat(after.id).isEqualTo(before.id);
	}

	assertThat(after.tag).isEqualTo(before.tag);
	assertThat(after.author).isEqualTo(before.author);
	assertThat(after.realAuthor).isEqualTo(before.realAuthor);
	assertThat(after._revisionNumber).isEqualTo(before._revisionNumber);

	if (i == deletedMessageIndex) {
	assertThat(after.message).isEqualTo(expectedDeleteMessage);
	} else {
	assertThat(after.message).isEqualTo(before.message);
	}
	}
	}

	private void assertMetaCommitsAfterDeletion(
	List<RevCommit> commitsBeforeDeletion,
	int changeNum,
	String deletedMessageId,
	TestAccount deletedBy,
	String deleteReason)
	throws Exception {
	List<RevCommit> commitsAfterDeletion = getChangeMetaCommitsInReverseOrder(Change.id(changeNum));
	assertThat(commitsAfterDeletion).hasSize(commitsBeforeDeletion.size());

	for (int i = 0; i < commitsBeforeDeletion.size(); i++) {
	RevCommit commitBefore = commitsBeforeDeletion.get(i);
	RevCommit commitAfter = commitsAfterDeletion.get(i);
	if (commitBefore.getId().getName().equals(deletedMessageId)) {
	byte[] rawBefore = commitBefore.getRawBuffer();
	byte[] rawAfter = commitAfter.getRawBuffer();
	Charset encodingBefore = RawParseUtils.parseEncoding(rawBefore);
	Charset encodingAfter = RawParseUtils.parseEncoding(rawAfter);
	Optional<ChangeNoteUtil.CommitMessageRange> rangeBefore =
	parseCommitMessageRange(commitBefore);
	Optional<ChangeNoteUtil.CommitMessageRange> rangeAfter =
	parseCommitMessageRange(commitAfter);
	assertThat(rangeBefore).isPresent();
	assertThat(rangeAfter).isPresent();

	String subjectBefore =
	decode(
	encodingBefore,
	rawBefore,
	rangeBefore.get().subjectStart(),
	rangeBefore.get().subjectEnd());
	String subjectAfter =
	decode(
	encodingAfter,
	rawAfter,
	rangeAfter.get().subjectStart(),
	rangeAfter.get().subjectEnd());
	assertThat(subjectBefore).isEqualTo(subjectAfter);

	String footersBefore =
	decode(
	encodingBefore,
	rawBefore,
	rangeBefore.get().changeMessageEnd() + 1,
	rawBefore.length);
	String footersAfter =
	decode(
	encodingAfter, rawAfter, rangeAfter.get().changeMessageEnd() + 1, rawAfter.length);
	assertThat(footersBefore).isEqualTo(footersAfter);

	String message =
	decode(
	encodingAfter,
	rawAfter,
	rangeAfter.get().changeMessageStart(),
	rangeAfter.get().changeMessageEnd() + 1);
	String expectedMessageTemplate =
	"Change message removed by: " + AccountTemplateUtil.getAccountTemplate(deletedBy.id());
	if (!Strings.isNullOrEmpty(deleteReason)) {
	expectedMessageTemplate = expectedMessageTemplate + "\nReason: " + deleteReason;
	}
	assertThat(message).isEqualTo(expectedMessageTemplate);
	} else {
	assertThat(commitAfter.getFullMessage()).isEqualTo(commitBefore.getFullMessage());
	}

	assertThat(commitAfter.getCommitterIdent().getName())
	.isEqualTo(commitBefore.getCommitterIdent().getName());
	assertThat(commitAfter.getAuthorIdent().getName())
	.isEqualTo(commitBefore.getAuthorIdent().getName());
	assertThat(commitAfter.getEncoding()).isEqualTo(commitBefore.getEncoding());
	assertThat(commitAfter.getEncodingName()).isEqualTo(commitBefore.getEncodingName());
	}
	}

	/** Verifies comments are not changed after deleting change message(s). */
	private void assertCommentsAfterDeletion(int changeNum, List<CommentInfo> commentsBeforeDeletion)
	throws Exception {
	List<CommentInfo> commentsAfterDeletion = getChangeSortedComments(changeNum);
	assertThat(commentsAfterDeletion).containsExactlyElementsIn(commentsBeforeDeletion).inOrder();
	}

	private static void assertMessage(String expected, String actual) {
	assertThat(actual).isEqualTo("Patch Set 1:\n\n" + expected);
	}

	private void postMessage(String changeId, String msg) throws Exception {
	postMessage(changeId, msg, null);
	}

	private void postMessage(String changeId, String msg, String tag) throws Exception {
	ReviewInput in = new ReviewInput();
	in.message = msg;
	in.tag = tag;
	gApi.changes().id(changeId).current().review(in);
	}
	}