Add new REST api for creating a merge patch set for change

Previously, we have a new feature that allow creating a new merge change (C2PS1) by merge a change(C1PS1) into a branch (release). If the original change (C1) is updated (C1PS2), the merged change also need to update (C2PS2) with a new merge with the updated change. master: C1PS1 -> C1PS2 \ \ release: C2PS1 -> C2PS2 Without this new merge patch set API, user have to abandon the old merge change(C2PS1) and then create a new merge change (C3PS1). REST api at `POST /changes/{change-id}/merge` and take a MergePatchSetInput. Change-Id: Ia3ba1bc5ff30920d1f8270f4fe28ccd7da7ed2a9
2016-09-23 12:59:48 -07:00
parent 886c95b98c
commit b1e07e52b2
7 changed files with 418 additions and 0 deletions
--- a/Documentation/rest-api-changes.txt
+++ b/Documentation/rest-api-changes.txt
@@ -517,6 +517,61 @@ describes the change.
  }
 ----

+[[create-merge-patch-set-for-change]]
+=== Create Merge Patch Set For Change
+--
+'POST /changes/link:#change-id[\{change-id\}]/merge'
+--
+
+Update an existing change by using a
+link:#merge-patch-set-input[MergePatchSetInput] entity.
+
+Gerrit will create a merge commit based on the information of
+MergePatchSetInput and add a new patch set to the change corresponding
+to the new merge commit.
+
+.Request
+----
+  POST /changes/test~master~Ic5466d107c5294414710935a8ef3b0180fb848dc/merge  HTTP/1.0
+  Content-Type: application/json; charset=UTF-8
+
+  {
+    "source": "refs/12/1234/1"
+  }
+----
+
+As response a link:#change-info[ChangeInfo] entity with current revision is
+returned that describes the resulting change.
+
+.Response
+----
+  HTTP/1.1 200 OK
+  Content-Disposition: attachment
+  Content-Type: application/json; charset=UTF-8
+
+  )]}'
+  {
+    "id": "test~master~Ic5466d107c5294414710935a8ef3b0180fb848dc",
+    "project": "test",
+    "branch": "master",
+    "hashtags": [],
+    "change_id": "Ic5466d107c5294414710935a8ef3b0180fb848dc",
+    "subject": "Merge dev_branch into master",
+    "status": "NEW",
+    "created": "2016-09-23 18:08:53.238000000",
+    "updated": "2016-09-23 18:09:25.934000000",
+    "submit_type": "MERGE_IF_NECESSARY",
+    "mergeable": true,
+    "insertions": 5,
+    "deletions": 0,
+    "_number": 72,
+    "owner": {
+      "_account_id": 1000000
+    },
+    "current_revision": "27cc4558b5a3d3387dd11ee2df7a117e7e581822"
+  }
+----
+
 [[get-change-detail]]
 === Get Change Detail
 --
@@ -5363,6 +5418,25 @@ The strategy of the merge, can be `recursive`, `resolve`,
 `simple-two-way-in-core`, `ours` or `theirs`, default will use project settings.
 |============================

+[[merge-patch-set-input]]
+=== MergePatchSetInput
+The `MergePatchSetInput` entity contains information about updating a new
+change by creating a new merge commit.
+
+[options="header",cols="1,^1,5"]
+|==================================
+|Field Name           ||Description
+|`subject`            |optional|
+The new subject for the change, if not specified, will reuse the current patch
+set's subject
+|`inheritParent`      |optional, default to `false`|
+Use the current patch set's first parent as the merge tip when set to `true`.
+Otherwise, use the current branch tip of the destination branch.
+|`merge`              ||
+The detail of the source commit for merge as a link:#merge-input[MergeInput]
+entity.
+|==================================
+
 [[move-input]]
 === MoveInput
 The `MoveInput` entity contains information for moving a change to a new branch.
--- a/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/api/change/ChangeIT.java
+++ b/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/api/change/ChangeIT.java
@@ -61,9 +61,11 @@ import com.google.gerrit.extensions.common.ApprovalInfo;
 import com.google.gerrit.extensions.common.ChangeInfo;
 import com.google.gerrit.extensions.common.ChangeInput;
 import com.google.gerrit.extensions.common.ChangeMessageInfo;
+import com.google.gerrit.extensions.common.MergePatchSetInput;
 import com.google.gerrit.extensions.common.CommitInfo;
 import com.google.gerrit.extensions.common.GitPerson;
 import com.google.gerrit.extensions.common.LabelInfo;
+import com.google.gerrit.extensions.common.MergeInput;
 import com.google.gerrit.extensions.common.RevisionInfo;
 import com.google.gerrit.extensions.restapi.AuthException;
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
@@ -71,6 +73,7 @@ import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
 import com.google.gerrit.extensions.restapi.UnprocessableEntityException;
 import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.AccountGroup;
+import com.google.gerrit.reviewdb.client.Branch;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.LabelId;
 import com.google.gerrit.reviewdb.client.PatchSet;
@@ -1930,6 +1933,86 @@ public class ChangeIT extends AbstractDaemonTest {
        + r1.getChange().getId().id + ".");
  }

+  @Test
+  public void testCreateMergePatchSet() throws Exception {
+    PushOneCommit.Result start = pushTo("refs/heads/master");
+    start.assertOkStatus();
+    // create a change for master
+    PushOneCommit.Result r = createChange();
+    r.assertOkStatus();
+    String changeId = r.getChangeId();
+
+    testRepo.reset(start.getCommit());
+    PushOneCommit.Result currentMaster = pushTo("refs/heads/master");
+    currentMaster.assertOkStatus();
+    String parent = currentMaster.getCommit().getName();
+
+    // push a commit into dev branch
+    createBranch(new Branch.NameKey(project, "dev"));
+    PushOneCommit.Result changeA = pushFactory
+        .create(db, user.getIdent(), testRepo, "change A", "A.txt", "A content")
+        .to("refs/heads/dev");
+    changeA.assertOkStatus();
+    MergeInput mergeInput = new MergeInput();
+    mergeInput.source = "dev";
+    MergePatchSetInput in = new MergePatchSetInput();
+    in.merge = mergeInput;
+    in.subject = "update change by merge ps2";
+    gApi.changes().id(changeId).createMergePatchSet(in);
+    ChangeInfo changeInfo = gApi.changes().id(changeId)
+        .get(EnumSet.of(ListChangesOption.ALL_REVISIONS,
+            ListChangesOption.CURRENT_COMMIT,
+            ListChangesOption.CURRENT_REVISION));
+    assertThat(changeInfo.revisions.size()).isEqualTo(2);
+    assertThat(changeInfo.subject).isEqualTo(in.subject);
+    assertThat(
+        changeInfo.revisions.get(changeInfo.currentRevision).commit.parents
+            .get(0).commit).isEqualTo(parent);
+  }
+
+  @Test
+  public void testCreateMergePatchSetInheritParent() throws Exception {
+    PushOneCommit.Result start = pushTo("refs/heads/master");
+    start.assertOkStatus();
+    // create a change for master
+    PushOneCommit.Result r = createChange();
+    r.assertOkStatus();
+    String changeId = r.getChangeId();
+    String parent = r.getCommit().getParent(0).getName();
+
+    // advance master branch
+    testRepo.reset(start.getCommit());
+    PushOneCommit.Result currentMaster = pushTo("refs/heads/master");
+    currentMaster.assertOkStatus();
+
+    // push a commit into dev branch
+    createBranch(new Branch.NameKey(project, "dev"));
+    PushOneCommit.Result changeA = pushFactory
+        .create(db, user.getIdent(), testRepo, "change A", "A.txt", "A content")
+        .to("refs/heads/dev");
+    changeA.assertOkStatus();
+    MergeInput mergeInput = new MergeInput();
+    mergeInput.source = "dev";
+    MergePatchSetInput in = new MergePatchSetInput();
+    in.merge = mergeInput;
+    in.subject = "update change by merge ps2 inherit parent of ps1";
+    in.inheritParent = true;
+    gApi.changes().id(changeId).createMergePatchSet(in);
+    ChangeInfo changeInfo = gApi.changes().id(changeId)
+        .get(EnumSet.of(ListChangesOption.ALL_REVISIONS,
+            ListChangesOption.CURRENT_COMMIT,
+            ListChangesOption.CURRENT_REVISION));
+
+    assertThat(changeInfo.revisions.size()).isEqualTo(2);
+    assertThat(changeInfo.subject).isEqualTo(in.subject);
+    assertThat(
+        changeInfo.revisions.get(changeInfo.currentRevision).commit.parents
+            .get(0).commit).isEqualTo(parent);
+    assertThat(
+        changeInfo.revisions.get(changeInfo.currentRevision).commit.parents
+            .get(0).commit).isNotEqualTo(currentMaster.getCommit().getName());
+  }
+
  private static Iterable<Account.Id> getReviewers(
      Collection<AccountInfo> r) {
    return Iterables.transform(r, a -> new Account.Id(a._accountId));
--- a/gerrit-extension-api/src/main/java/com/google/gerrit/extensions/api/changes/ChangeApi.java
+++ b/gerrit-extension-api/src/main/java/com/google/gerrit/extensions/api/changes/ChangeApi.java
@@ -17,6 +17,7 @@ package com.google.gerrit.extensions.api.changes;
 import com.google.gerrit.extensions.client.ListChangesOption;
 import com.google.gerrit.extensions.common.AccountInfo;
 import com.google.gerrit.extensions.common.ChangeInfo;
+import com.google.gerrit.extensions.common.MergePatchSetInput;
 import com.google.gerrit.extensions.common.CommentInfo;
 import com.google.gerrit.extensions.common.EditInfo;
 import com.google.gerrit.extensions.common.SuggestedReviewerInfo;
@@ -95,6 +96,9 @@ public interface ChangeApi {
   */
  ChangeApi revert(RevertInput in) throws RestApiException;

+  /** Create a merge patch set for the change. */
+  ChangeInfo createMergePatchSet(MergePatchSetInput in) throws RestApiException;
+
  List<ChangeInfo> submittedTogether() throws RestApiException;
  SubmittedTogetherInfo submittedTogether(
      EnumSet<SubmittedTogetherOption> options) throws RestApiException;
@@ -412,5 +416,11 @@ public interface ChangeApi {
        EnumSet<SubmittedTogetherOption> b) throws RestApiException {
      throw new NotImplementedException();
    }
+
+    @Override
+    public ChangeInfo createMergePatchSet(MergePatchSetInput in)
+        throws RestApiException {
+      throw new NotImplementedException();
+    }
  }
 }
--- a/gerrit-extension-api/src/main/java/com/google/gerrit/extensions/common/MergePatchSetInput.java
+++ b/gerrit-extension-api/src/main/java/com/google/gerrit/extensions/common/MergePatchSetInput.java
@@ -0,0 +1,21 @@
+// Copyright (C) 2016 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.extensions.common;
+
+public class MergePatchSetInput {
+  public String subject;
+  public boolean inheritParent;
+  public MergeInput merge;
+}
--- a/gerrit-server/src/main/java/com/google/gerrit/server/api/changes/ChangeApiImpl.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/api/changes/ChangeApiImpl.java
@@ -31,6 +31,7 @@ import com.google.gerrit.extensions.api.changes.SubmittedTogetherOption;
 import com.google.gerrit.extensions.client.ListChangesOption;
 import com.google.gerrit.extensions.common.AccountInfo;
 import com.google.gerrit.extensions.common.ChangeInfo;
+import com.google.gerrit.extensions.common.MergePatchSetInput;
 import com.google.gerrit.extensions.common.CommentInfo;
 import com.google.gerrit.extensions.common.EditInfo;
 import com.google.gerrit.extensions.common.SuggestedReviewerInfo;
@@ -63,7 +64,9 @@ import com.google.gerrit.server.change.Reviewers;
 import com.google.gerrit.server.change.Revisions;
 import com.google.gerrit.server.change.SubmittedTogether;
 import com.google.gerrit.server.change.SuggestChangeReviewers;
+import com.google.gerrit.server.change.CreateMergePatchSet;
 import com.google.gerrit.server.git.UpdateException;
+import com.google.gerrit.server.project.InvalidChangeOperationException;
 import com.google.gerrit.server.project.NoSuchChangeException;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
@@ -91,6 +94,7 @@ class ChangeApiImpl implements ChangeApi {
  private final Abandon abandon;
  private final Revert revert;
  private final Restore restore;
+  private final CreateMergePatchSet updateByMerge;
  private final Provider<SubmittedTogether> submittedTogether;
  private final PublishDraftPatchSet.CurrentRevision
    publishDraftChange;
@@ -122,6 +126,7 @@ class ChangeApiImpl implements ChangeApi {
      Abandon abandon,
      Revert revert,
      Restore restore,
+      CreateMergePatchSet updateByMerge,
      Provider<SubmittedTogether> submittedTogether,
      PublishDraftPatchSet.CurrentRevision publishDraftChange,
      DeleteDraftChange deleteDraftChange,
@@ -151,6 +156,7 @@ class ChangeApiImpl implements ChangeApi {
    this.suggestReviewers = suggestReviewers;
    this.abandon = abandon;
    this.restore = restore;
+    this.updateByMerge = updateByMerge;
    this.submittedTogether = submittedTogether;
    this.publishDraftChange = publishDraftChange;
    this.deleteDraftChange = deleteDraftChange;
@@ -267,6 +273,17 @@ class ChangeApiImpl implements ChangeApi {
    }
  }

+  @Override
+  public ChangeInfo createMergePatchSet(MergePatchSetInput in)
+      throws RestApiException {
+    try {
+      return updateByMerge.apply(change, in).value();
+    } catch (IOException | UpdateException | InvalidChangeOperationException
+        | NoSuchChangeException | OrmException e) {
+      throw new RestApiException("Cannot update change by merge", e);
+    }
+  }
+
  @Override
  public List<ChangeInfo> submittedTogether() throws RestApiException {
    SubmittedTogetherInfo info = submittedTogether(
--- a/gerrit-server/src/main/java/com/google/gerrit/server/change/CreateMergePatchSet.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/change/CreateMergePatchSet.java
@@ -0,0 +1,212 @@
+// Copyright (C) 2016 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.server.change;
+
+import com.google.common.base.MoreObjects;
+import com.google.common.base.Strings;
+import com.google.gerrit.common.TimeUtil;
+import com.google.gerrit.extensions.api.changes.NotifyHandling;
+import com.google.gerrit.extensions.client.ListChangesOption;
+import com.google.gerrit.extensions.common.ChangeInfo;
+import com.google.gerrit.extensions.common.MergePatchSetInput;
+import com.google.gerrit.extensions.common.MergeInput;
+import com.google.gerrit.extensions.restapi.AuthException;
+import com.google.gerrit.extensions.restapi.BadRequestException;
+import com.google.gerrit.extensions.restapi.MergeConflictException;
+import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
+import com.google.gerrit.extensions.restapi.Response;
+import com.google.gerrit.extensions.restapi.RestApiException;
+import com.google.gerrit.extensions.restapi.RestModifyView;
+import com.google.gerrit.reviewdb.client.Branch;
+import com.google.gerrit.reviewdb.client.Change;
+import com.google.gerrit.reviewdb.client.PatchSet;
+import com.google.gerrit.reviewdb.client.Project;
+import com.google.gerrit.reviewdb.server.ReviewDb;
+import com.google.gerrit.server.ChangeUtil;
+import com.google.gerrit.server.CurrentUser;
+import com.google.gerrit.server.GerritPersonIdent;
+import com.google.gerrit.server.IdentifiedUser;
+import com.google.gerrit.server.PatchSetUtil;
+import com.google.gerrit.server.git.BatchUpdate;
+import com.google.gerrit.server.git.GitRepositoryManager;
+import com.google.gerrit.server.git.MergeIdenticalTreeException;
+import com.google.gerrit.server.git.MergeUtil;
+import com.google.gerrit.server.git.UpdateException;
+import com.google.gerrit.server.project.ChangeControl;
+import com.google.gerrit.server.project.InvalidChangeOperationException;
+import com.google.gerrit.server.project.NoSuchChangeException;
+import com.google.gerrit.server.project.ProjectControl;
+import com.google.gwtorm.server.OrmException;
+import com.google.inject.Inject;
+import com.google.inject.Provider;
+import com.google.inject.Singleton;
+
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.ObjectInserter;
+import org.eclipse.jgit.lib.PersonIdent;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.revwalk.RevWalk;
+import org.eclipse.jgit.util.ChangeIdUtil;
+
+import java.io.IOException;
+import java.sql.Timestamp;
+import java.util.EnumSet;
+import java.util.TimeZone;
+
+@Singleton
+public class CreateMergePatchSet implements
+    RestModifyView<ChangeResource, MergePatchSetInput> {
+
+  private final Provider<ReviewDb> db;
+  private final GitRepositoryManager gitManager;
+  private final TimeZone serverTimeZone;
+  private final Provider<CurrentUser> user;
+  private final ChangeJson.Factory jsonFactory;
+  private final PatchSetUtil psUtil;
+  private final MergeUtil.Factory mergeUtilFactory;
+  private final BatchUpdate.Factory batchUpdateFactory;
+  private final PatchSetInserter.Factory patchSetInserterFactory;
+
+  @Inject
+  CreateMergePatchSet(Provider<ReviewDb> db,
+      GitRepositoryManager gitManager,
+      @GerritPersonIdent PersonIdent myIdent,
+      Provider<CurrentUser> user,
+      ChangeJson.Factory json,
+      PatchSetUtil psUtil,
+      MergeUtil.Factory mergeUtilFactory,
+      BatchUpdate.Factory batchUpdateFactory,
+      PatchSetInserter.Factory patchSetInserterFactory) {
+    this.db = db;
+    this.gitManager = gitManager;
+    this.serverTimeZone = myIdent.getTimeZone();
+    this.user = user;
+    this.jsonFactory = json;
+    this.psUtil = psUtil;
+    this.mergeUtilFactory = mergeUtilFactory;
+    this.batchUpdateFactory = batchUpdateFactory;
+    this.patchSetInserterFactory = patchSetInserterFactory;
+  }
+
+  @Override
+  public Response<ChangeInfo> apply(ChangeResource req, MergePatchSetInput in)
+      throws NoSuchChangeException, OrmException, IOException,
+      InvalidChangeOperationException, RestApiException, UpdateException {
+    if (in.merge == null) {
+      throw new BadRequestException("merge field is required");
+    }
+
+    MergeInput merge = in.merge;
+    if (Strings.isNullOrEmpty(merge.source)) {
+      throw new BadRequestException("merge.source must be non-empty");
+    }
+
+    ChangeControl ctl = req.getControl();
+    if (!ctl.isVisible(db.get())) {
+      throw new InvalidChangeOperationException(
+          "Base change not found: " + req.getId());
+    }
+    PatchSet ps = psUtil.current(db.get(), ctl.getNotes());
+    if (!ctl.canAddPatchSet(db.get())) {
+      throw new AuthException("cannot add patch set");
+    }
+
+    ProjectControl projectControl = ctl.getProjectControl();
+    Change change = ctl.getChange();
+    Project.NameKey project = change.getProject();
+    Branch.NameKey dest = change.getDest();
+    try (Repository git = gitManager.openRepository(project);
+        ObjectInserter oi = git.newObjectInserter();
+        RevWalk rw = new RevWalk(oi.newReader())) {
+
+      RevCommit sourceCommit =
+          MergeUtil.resolveCommit(git, rw, merge.source);
+      if (!projectControl.canReadCommit(db.get(), git, sourceCommit)) {
+        throw new ResourceNotFoundException(
+            "cannot find source commit: " + merge.source + " to merge.");
+      }
+
+      RevCommit currentPsCommit =
+          rw.parseCommit(ObjectId.fromString(ps.getRevision().get()));
+
+      Timestamp now = TimeUtil.nowTs();
+      IdentifiedUser me = user.get().asIdentifiedUser();
+      PersonIdent author = me.newCommitterIdent(now, serverTimeZone);
+
+      RevCommit newCommit =
+          createMergeCommit(in, projectControl, dest, git, oi, rw,
+              currentPsCommit, sourceCommit, author,
+              ObjectId.fromString(change.getKey().get().substring(1)));
+
+      PatchSet.Id nextPsId = ChangeUtil.nextPatchSetId(ps.getId());
+      PatchSetInserter psInserter =
+          patchSetInserterFactory.create(ctl, nextPsId, newCommit);
+      try (BatchUpdate bu = batchUpdateFactory
+          .create(db.get(), project, me, now)) {
+        bu.setRepository(git, rw, oi);
+        bu.addOp(ctl.getId(), psInserter
+            .setMessage("Uploaded patch set " + nextPsId.get() + ".")
+            .setDraft(ps.isDraft())
+            .setNotify(NotifyHandling.NONE));
+        bu.execute();
+      }
+
+      ChangeJson json =
+          jsonFactory.create(EnumSet.of(ListChangesOption.CURRENT_REVISION));
+      return Response.ok(json.format(psInserter.getChange()));
+    }
+  }
+
+  private RevCommit createMergeCommit(MergePatchSetInput in,
+      ProjectControl projectControl, Branch.NameKey dest, Repository git,
+      ObjectInserter oi, RevWalk rw, RevCommit currentPsCommit,
+      RevCommit sourceCommit, PersonIdent author, ObjectId changeId)
+      throws ResourceNotFoundException, MergeIdenticalTreeException,
+      MergeConflictException, IOException {
+
+    ObjectId parentCommit;
+    if (in.inheritParent) {
+      // inherit first parent from previous patch set
+      parentCommit = currentPsCommit.getParent(0);
+    } else {
+      // get the current branch tip of destination branch
+      Ref destRef = git.getRefDatabase().exactRef(dest.get());
+      if (destRef != null) {
+        parentCommit = destRef.getObjectId();
+      } else {
+        throw new ResourceNotFoundException("cannot find destination branch");
+      }
+    }
+    RevCommit mergeTip = rw.parseCommit(parentCommit);
+
+    String commitMsg;
+    if (Strings.emptyToNull(in.subject) != null) {
+      commitMsg = ChangeIdUtil.insertId(in.subject, changeId);
+    } else {
+      // reuse previous patch set commit message
+      commitMsg = currentPsCommit.getFullMessage();
+    }
+
+    String mergeStrategy = MoreObjects.firstNonNull(
+        Strings.emptyToNull(in.merge.strategy),
+        mergeUtilFactory.create(projectControl.getProjectState())
+            .mergeStrategyName());
+
+    return MergeUtil.createMergeCommit(git, oi, mergeTip, sourceCommit,
+        mergeStrategy, author, commitMsg, rw);
+  }
+}
--- a/gerrit-server/src/main/java/com/google/gerrit/server/change/Module.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/change/Module.java
@@ -53,6 +53,7 @@ public class Module extends RestApiModule {
    DynamicMap.mapOf(binder(), VOTE_KIND);

    get(CHANGE_KIND).to(GetChange.class);
+    post(CHANGE_KIND, "merge").to(CreateMergePatchSet.class);
    get(CHANGE_KIND, "detail").to(GetDetail.class);
    get(CHANGE_KIND, "topic").to(GetTopic.class);
    get(CHANGE_KIND, "in").to(IncludedIn.class);