Add REST API endpoint to delete a tag

Also-by: Paladox none <thomasmulhall410@yahoo.com>
Change-Id: I40f0a2ca40a615aa2bf757171aaf393afd9eb8ad

Documentation/rest-api-projects.txt

@@ -1886,6 +1886,23 @@ As response a link:#tag-info[TagInfo] entity is returned that describes the tag.
   }
 ----
 
+[[delete-tag]]
+=== Delete Tag
+--
+'DELETE /projects/link:#project-name[\{project-name\}]/tags/link:#tag-id[\{tag-id\}]'
+--
+
+Deletes a tag.
+
+.Request
+----
+  DELETE /projects/MyProject/tags/v1.0 HTTP/1.0
+----
+
+.Response
+----
+  HTTP/1.1 204 No Content
+----
 
 [[commit-endpoints]]
 == Commit Endpoints

gerrit-extension-api/src/main/java/com/google/gerrit/extensions/api/projects/TagApi.java

@@ -22,6 +22,8 @@ public interface TagApi {
 
   TagInfo get() throws RestApiException;
 
+  void delete() throws RestApiException;
+
   /**
    * A default implementation which allows source compatibility
    * when adding new methods to the interface.
@@ -36,5 +38,10 @@ public interface TagApi {
     public TagInfo get() throws RestApiException {
       throw new NotImplementedException();
     }
+
+    @Override
+    public void delete() throws RestApiException {
+      throw new NotImplementedException();
+    }
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/api/projects/TagApiImpl.java

@@ -20,8 +20,12 @@ import com.google.gerrit.extensions.api.projects.TagInput;
 import com.google.gerrit.extensions.restapi.IdString;
 import com.google.gerrit.extensions.restapi.RestApiException;
 import com.google.gerrit.server.project.CreateTag;
+import com.google.gerrit.server.project.DeleteTag;
 import com.google.gerrit.server.project.ListTags;
 import com.google.gerrit.server.project.ProjectResource;
+import com.google.gerrit.server.project.TagResource;
+import com.google.gerrit.server.project.TagsCollection;
+import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.assistedinject.Assisted;
 
@@ -34,16 +38,22 @@ public class TagApiImpl implements TagApi {
 
   private final ListTags listTags;
   private final CreateTag.Factory createTagFactory;
+  private final DeleteTag deleteTag;
+  private final TagsCollection tags;
   private final String ref;
   private final ProjectResource project;
 
   @Inject
   TagApiImpl(ListTags listTags,
       CreateTag.Factory createTagFactory,
+      DeleteTag deleteTag,
+      TagsCollection tags,
       @Assisted ProjectResource project,
       @Assisted String ref) {
     this.listTags = listTags;
     this.createTagFactory = createTagFactory;
+    this.deleteTag = deleteTag;
+    this.tags = tags;
     this.project = project;
     this.ref = ref;
   }
@@ -66,4 +76,17 @@ public class TagApiImpl implements TagApi {
       throw new RestApiException(e.getMessage());
     }
   }
+
+  @Override
+  public void delete() throws RestApiException {
+    try {
+      deleteTag.apply(resource(), new DeleteTag.Input());
+    } catch (OrmException | IOException e) {
+      throw new RestApiException(e.getMessage());
+    }
+  }
+
+  private TagResource resource() throws RestApiException, IOException {
+    return tags.parse(project, IdString.fromDecoded(ref));
+  }
 }

gerrit-server/src/main/java/com/google/gerrit/server/project/CreateTag.java

@@ -14,7 +14,6 @@
 
 package com.google.gerrit.server.project;
 
-import static org.eclipse.jgit.lib.Constants.R_REFS;
 import static org.eclipse.jgit.lib.Constants.R_TAGS;
 
 import com.google.common.base.Strings;
@@ -90,18 +89,8 @@ public class CreateTag implements RestModifyView<ProjectResource, TagInput> {
     if (input.revision == null) {
       input.revision = Constants.HEAD;
     }
-    while (ref.startsWith("/")) {
-      ref = ref.substring(1);
-    }
-    if (ref.startsWith(R_REFS) && !ref.startsWith(R_TAGS)) {
-      throw new BadRequestException("invalid tag name \"" + ref + "\"");
-    }
-    if (!ref.startsWith(R_TAGS)) {
-      ref = R_TAGS + ref;
-    }
-    if (!Repository.isValidRefName(ref)) {
-      throw new BadRequestException("invalid tag name \"" + ref + "\"");
-    }
+
+    ref = RefUtil.normalizeTagRef(ref);
 
     RefControl refControl = resource.getControl().controlForRef(ref);
     try (Repository repo = repoManager.openRepository(resource.getNameKey())) {

gerrit-server/src/main/java/com/google/gerrit/server/project/DeleteRef.java

@@ -15,6 +15,7 @@
 package com.google.gerrit.server.project;
 
 import static java.lang.String.format;
+import static org.eclipse.jgit.lib.Constants.R_TAGS;
 import static org.eclipse.jgit.transport.ReceiveCommand.Type.DELETE;
 
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
@@ -197,12 +198,13 @@ public class DeleteRef {
           "it doesn't exist or you do not have permission to delete it");
     }
 
-    //TODO: this check should not be done when deletion of tags is added
+    if (!refName.startsWith(R_TAGS)) {
       Branch.NameKey branchKey =
           new Branch.NameKey(project.getNameKey(), ref.getName());
       if (!queryProvider.get().setLimit(1).byBranchOpen(branchKey).isEmpty()) {
         command.setResult(Result.REJECTED_OTHER_REASON, "it has open changes");
       }
+    }
 
     RefUpdate u = r.updateRef(refName);
     u.setForceUpdate(true);

gerrit-server/src/main/java/com/google/gerrit/server/project/DeleteTag.java

@@ -0,0 +1,52 @@
+// 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.project;
+
+import com.google.gerrit.extensions.restapi.AuthException;
+import com.google.gerrit.extensions.restapi.Response;
+import com.google.gerrit.extensions.restapi.RestApiException;
+import com.google.gerrit.extensions.restapi.RestModifyView;
+import com.google.gwtorm.server.OrmException;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+import java.io.IOException;
+
+@Singleton
+public class DeleteTag implements RestModifyView<TagResource, DeleteTag.Input> {
+  private final DeleteRef.Factory deleteRefFactory;
+
+  public static class Input {
+  }
+
+  @Inject
+  DeleteTag(DeleteRef.Factory deleteRefFactory) {
+    this.deleteRefFactory = deleteRefFactory;
+  }
+
+  @Override
+  public Response<?> apply(TagResource resource, Input input)
+      throws OrmException, RestApiException, IOException {
+    String tag = RefUtil.normalizeTagRef(resource.getTagInfo().ref);
+    RefControl refControl = resource.getControl().controlForRef(tag);
+
+    if (!refControl.canDelete()) {
+      throw new AuthException("Cannot delete tag");
+    }
+
+    deleteRefFactory.create(resource).ref(tag).delete();
+    return Response.none();
+  }
+}

gerrit-server/src/main/java/com/google/gerrit/server/project/Module.java

@@ -81,6 +81,7 @@ public class Module extends RestApiModule {
     child(PROJECT_KIND, "tags").to(TagsCollection.class);
     get(TAG_KIND).to(GetTag.class);
     put(TAG_KIND).to(PutTag.class);
+    delete(TAG_KIND).to(DeleteTag.class);
     factory(CreateTag.Factory.class);
 
     child(PROJECT_KIND, "dashboards").to(DashboardsCollection.class);

gerrit-server/src/main/java/com/google/gerrit/server/project/RefUtil.java

@@ -14,7 +14,11 @@
 
 package com.google.gerrit.server.project;
 
+import static org.eclipse.jgit.lib.Constants.R_REFS;
+import static org.eclipse.jgit.lib.Constants.R_TAGS;
+
 import com.google.common.collect.Iterables;
+import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.reviewdb.client.RefNames;
 
@@ -99,6 +103,23 @@ public class RefUtil {
     return Constants.R_HEADS;
   }
 
+  public static String normalizeTagRef(String tag) throws BadRequestException {
+    String result = tag;
+    while (result.startsWith("/")) {
+      result = result.substring(1);
+    }
+    if (result.startsWith(R_REFS) && !result.startsWith(R_TAGS)) {
+      throw new BadRequestException("invalid tag name \"" + result + "\"");
+    }
+    if (!result.startsWith(R_TAGS)) {
+      result = R_TAGS + result;
+    }
+    if (!Repository.isValidRefName(result)) {
+      throw new BadRequestException("invalid tag name \"" + result + "\"");
+    }
+    return result;
+  }
+
   /** Error indicating the revision is invalid as supplied. */
   static class InvalidRevisionException extends Exception {
     private static final long serialVersionUID = 1L;