Support multiple assignees for Issues and Pull requests (#3055)

2025-11-07 14:05:52 +01:00 · 2022-05-03 22:51:54 +09:00
parent a800f305f2
commit 79dc6fc247
28 changed files with 394 additions and 175 deletions
--- a/src/main/resources/update/gitbucket-core_4.38.xml
+++ b/src/main/resources/update/gitbucket-core_4.38.xml
@@ -28,4 +28,26 @@
  <addPrimaryKey constraintName="IDX_ISSUE_CUSTOM_FIELD_PK" tableName="ISSUE_CUSTOM_FIELD" columnNames="USER_NAME, REPOSITORY_NAME, ISSUE_ID, FIELD_ID"/>
  <addForeignKeyConstraint constraintName="IDX_ISSUE_CUSTOM_FIELD_FK0" baseTableName="ISSUE_CUSTOM_FIELD" baseColumnNames="USER_NAME, REPOSITORY_NAME, ISSUE_ID" referencedTableName="ISSUE" referencedColumnNames="USER_NAME, REPOSITORY_NAME, ISSUE_ID"/>
  <addForeignKeyConstraint constraintName="IDX_ISSUE_CUSTOM_FIELD_FK1" baseTableName="ISSUE_CUSTOM_FIELD" baseColumnNames="USER_NAME, REPOSITORY_NAME, FIELD_ID" referencedTableName="CUSTOM_FIELD" referencedColumnNames="USER_NAME, REPOSITORY_NAME, FIELD_ID"/>
+
+  <!--================================================================================================-->
+  <!-- ISSUE_ASSIGNEE -->
+  <!--================================================================================================-->
+  <createTable tableName="ISSUE_ASSIGNEE">
+    <column name="USER_NAME" type="varchar(100)" nullable="false"/>
+    <column name="REPOSITORY_NAME" type="varchar(100)" nullable="false"/>
+    <column name="ISSUE_ID" type="int" nullable="false"/>
+    <column name="ASSIGNEE_USER_NAME" type="varchar(100)" nullable="false"/>
+  </createTable>
+  <addPrimaryKey constraintName="IDX_ISSUE_ASSIGNEE_PK" tableName="ISSUE_ASSIGNEE" columnNames="USER_NAME, REPOSITORY_NAME, ISSUE_ID, ASSIGNEE_USER_NAME"/>
+  <addForeignKeyConstraint constraintName="IDX_ISSUE_ASSIGNEE_FK0" baseTableName="ISSUE_ASSIGNEE" baseColumnNames="USER_NAME, REPOSITORY_NAME, ISSUE_ID" referencedTableName="ISSUE" referencedColumnNames="USER_NAME, REPOSITORY_NAME, ISSUE_ID"/>
+  <!--
+  <addForeignKeyConstraint constraintName="IDX_ISSUE_ASSIGNEE_FK1" baseTableName="ISSUE_ASSIGNEE" baseColumnNames="ASSIGNEE_USER_NAME" referencedTableName="ACCOUNT" referencedColumnNames="USER_NAME"/>
+  -->
+
+  <sql>
+    INSERT INTO ISSUE_ASSIGNEE (USER_NAME, REPOSITORY_NAME, ISSUE_ID, ASSIGNEE_USER_NAME)
+      SELECT USER_NAME, REPOSITORY_NAME, ISSUE_ID, ASSIGNED_USER_NAME FROM ISSUE WHERE ASSIGNED_USER_NAME IS NOT NULL
+  </sql>
+
+  <dropColumn tableName="ISSUE" columnName="ASSIGNED_USER_NAME"/>
 </changeSet>
--- a/src/main/scala/gitbucket/core/api/ApiIssue.scala
+++ b/src/main/scala/gitbucket/core/api/ApiIssue.scala
@@ -12,7 +12,7 @@ case class ApiIssue(
  number: Int,
  title: String,
  user: ApiUser,
-  assignee: Option[ApiUser],
+  assignees: List[ApiUser],
  labels: List[ApiLabel],
  state: String,
  created_at: Date,
@@ -21,7 +21,7 @@ case class ApiIssue(
  milestone: Option[ApiMilestone]
 )(repositoryName: RepositoryName, isPullRequest: Boolean) {
  val id = 0 // dummy id
-  val assignees = List(assignee).flatten
+  val assignee = assignees.headOption
  val comments_url = ApiPath(s"/api/v3/repos/${repositoryName.fullName}/issues/${number}/comments")
  val html_url = ApiPath(s"/${repositoryName.fullName}/${if (isPullRequest) { "pull" } else { "issues" }}/${number}")
  val pull_request = if (isPullRequest) {
@@ -43,7 +43,7 @@ object ApiIssue {
    issue: Issue,
    repositoryName: RepositoryName,
    user: ApiUser,
-    assignee: Option[ApiUser],
+    assignees: List[ApiUser],
    labels: List[ApiLabel],
    milestone: Option[ApiMilestone]
  ): ApiIssue =
@@ -51,7 +51,7 @@ object ApiIssue {
      number = issue.issueId,
      title = issue.title,
      user = user,
-      assignee = assignee,
+      assignees = assignees,
      labels = labels,
      milestone = milestone,
      state = if (issue.closed) { "closed" } else { "open" },
--- a/src/main/scala/gitbucket/core/api/ApiPullRequest.scala
+++ b/src/main/scala/gitbucket/core/api/ApiPullRequest.scala
@@ -21,10 +21,11 @@ case class ApiPullRequest(
  body: String,
  user: ApiUser,
  labels: List[ApiLabel],
-  assignee: Option[ApiUser],
+  assignees: List[ApiUser],
  draft: Option[Boolean]
 ) {
  val id = 0 // dummy id
+  val assignee = assignees.headOption
  val html_url = ApiPath(s"${base.repo.html_url.path}/pull/${number}")
  //val diff_url            = ApiPath(s"${base.repo.html_url.path}/pull/${number}.diff")
  //val patch_url           = ApiPath(s"${base.repo.html_url.path}/pull/${number}.patch")
@@ -45,7 +46,7 @@ object ApiPullRequest {
    baseRepo: ApiRepository,
    user: ApiUser,
    labels: List[ApiLabel],
-    assignee: Option[ApiUser],
+    assignees: List[ApiUser],
    mergedComment: Option[(IssueComment, Account)]
  ): ApiPullRequest =
    ApiPullRequest(
@@ -63,7 +64,7 @@ object ApiPullRequest {
      body = issue.content.getOrElse(""),
      user = user,
      labels = labels,
-      assignee = assignee,
+      assignees = assignees,
      draft = Some(pullRequest.isDraft)
    )

--- a/src/main/scala/gitbucket/core/controller/IssuesController.scala
+++ b/src/main/scala/gitbucket/core/controller/IssuesController.scala
@@ -53,7 +53,7 @@ trait IssuesControllerBase extends ControllerBase {
  case class IssueCreateForm(
    title: String,
    content: Option[String],
-    assignedUserName: Option[String],
+    assigneeUserNames: Option[String],
    milestoneId: Option[Int],
    priorityId: Option[Int],
    labelNames: Option[String]
@@ -64,7 +64,7 @@ trait IssuesControllerBase extends ControllerBase {
  val issueCreateForm = mapping(
    "title" -> trim(label("Title", text(required))),
    "content" -> trim(optional(text())),
-    "assignedUserName" -> trim(optional(text())),
+    "assigneeUserNames" -> trim(optional(text())),
    "milestoneId" -> trim(optional(number())),
    "priorityId" -> trim(optional(number())),
    "labelNames" -> trim(optional(text()))
@@ -107,6 +107,7 @@ trait IssuesControllerBase extends ControllerBase {
            issue,
            getComments(repository.owner, repository.name, issueId.toInt),
            getIssueLabels(repository.owner, repository.name, issueId.toInt),
+            getIssueAssignees(repository.owner, repository.name, issueId.toInt),
            getAssignableUserNames(repository.owner, repository.name),
            getMilestonesWithIssueCount(repository.owner, repository.name),
            getPriorities(repository.owner, repository.name),
@@ -145,7 +146,7 @@ trait IssuesControllerBase extends ControllerBase {
            repository,
            form.title,
            form.content,
-            form.assignedUserName,
+            form.assigneeUserNames.toSeq.flatMap(_.split(",")),
            form.milestoneId,
            form.priorityId,
            form.labelNames.toSeq.flatMap(_.split(",")),
@@ -356,15 +357,16 @@ trait IssuesControllerBase extends ControllerBase {
    html.labellist(getIssueLabels(repository.owner, repository.name, issueId))
  })

-  ajaxPost("/:owner/:repository/issues/:id/assign")(writableUsersOnly { repository =>
-    updateAssignedUserName(
-      repository.owner,
-      repository.name,
-      params("id").toInt,
-      assignedUserName("assignedUserName"),
-      true
-    )
-    Ok("updated")
+  ajaxPost("/:owner/:repository/issues/:id/assignee/new")(writableUsersOnly { repository =>
+    val issueId = params("id").toInt
+    registerIssueAssignee(repository.owner, repository.name, issueId, params("assigneeUserName"), true)
+    Ok()
+  })
+
+  ajaxPost("/:owner/:repository/issues/:id/assignee/delete")(writableUsersOnly { repository =>
+    val issueId = params("id").toInt
+    deleteIssueAssignee(repository.owner, repository.name, issueId, params("assigneeUserName"), true)
+    Ok()
  })

  ajaxPost("/:owner/:repository/issues/:id/milestone")(writableUsersOnly { repository =>
@@ -455,7 +457,13 @@ trait IssuesControllerBase extends ControllerBase {
  post("/:owner/:repository/issues/batchedit/assign")(writableUsersOnly { repository =>
    val value = assignedUserName("value")
    executeBatch(repository) {
-      updateAssignedUserName(repository.owner, repository.name, _, value, true)
+      //updateAssignedUserName(repository.owner, repository.name, _, value, true)
+      value match {
+        case Some(assignedUserName) =>
+          registerIssueAssignee(repository.owner, repository.name, _, assignedUserName, true)
+        case None =>
+          deleteAllIssueAssignees(repository.owner, repository.name, _, true)
+      }
    }
    if (params("uri").nonEmpty) {
      redirect(params("uri"))
--- a/src/main/scala/gitbucket/core/controller/LabelsController.scala
+++ b/src/main/scala/gitbucket/core/controller/LabelsController.scala
@@ -44,7 +44,7 @@ trait LabelsControllerBase extends ControllerBase {
  get("/:owner/:repository/issues/labels")(referrersOnly { repository =>
    html.list(
      getLabels(repository.owner, repository.name),
-      countIssueGroupByLabels(repository.owner, repository.name, IssuesService.IssueSearchCondition(), Map.empty),
+      countIssueGroupByLabels(repository.owner, repository.name, IssuesService.IssueSearchCondition()),
      repository,
      hasDeveloperRole(repository.owner, repository.name, context.loginAccount)
    )
@@ -59,7 +59,7 @@ trait LabelsControllerBase extends ControllerBase {
    html.label(
      getLabel(repository.owner, repository.name, labelId).get,
      // TODO futility
-      countIssueGroupByLabels(repository.owner, repository.name, IssuesService.IssueSearchCondition(), Map.empty),
+      countIssueGroupByLabels(repository.owner, repository.name, IssuesService.IssueSearchCondition()),
      repository,
      hasDeveloperRole(repository.owner, repository.name, context.loginAccount)
    )
@@ -76,7 +76,7 @@ trait LabelsControllerBase extends ControllerBase {
    html.label(
      getLabel(repository.owner, repository.name, params("labelId").toInt).get,
      // TODO futility
-      countIssueGroupByLabels(repository.owner, repository.name, IssuesService.IssueSearchCondition(), Map.empty),
+      countIssueGroupByLabels(repository.owner, repository.name, IssuesService.IssueSearchCondition()),
      repository,
      hasDeveloperRole(repository.owner, repository.name, context.loginAccount)
    )
--- a/src/main/scala/gitbucket/core/controller/PullRequestsController.scala
+++ b/src/main/scala/gitbucket/core/controller/PullRequestsController.scala
@@ -92,7 +92,7 @@ trait PullRequestsControllerBase extends ControllerBase {
    commitIdFrom: String,
    commitIdTo: String,
    isDraft: Boolean,
-    assignedUserName: Option[String],
+    assignedUserNames: Option[String],
    milestoneId: Option[Int],
    priorityId: Option[Int],
    labelNames: Option[String]
@@ -131,6 +131,7 @@ trait PullRequestsControllerBase extends ControllerBase {
              getPullRequestComments(repository.owner, repository.name, issue.issueId, commits.flatten),
              diffs.size,
              getIssueLabels(repository.owner, repository.name, issueId),
+              getIssueAssignees(repository.owner, repository.name, issueId),
              getAssignableUserNames(repository.owner, repository.name),
              getMilestonesWithIssueCount(repository.owner, repository.name),
              getPriorities(repository.owner, repository.name),
@@ -571,7 +572,6 @@ trait PullRequestsControllerBase extends ControllerBase {
          loginUser = loginAccount.userName,
          title = form.title,
          content = form.content,
-          assignedUserName = if (manageable) form.assignedUserName else None,
          milestoneId = if (manageable) form.milestoneId else None,
          priorityId = if (manageable) form.priorityId else None,
          isPullRequest = true
@@ -591,8 +591,14 @@ trait PullRequestsControllerBase extends ControllerBase {
          settings = context.settings
        )

-        // insert labels
        if (manageable) {
+          // insert assignees
+          form.assignedUserNames.foreach { value =>
+            value.split(",").foreach { userName =>
+              registerIssueAssignee(repository.owner, repository.name, issueId, userName)
+            }
+          }
+          // insert labels
          form.labelNames.foreach { value =>
            val labels = getLabels(repository.owner, repository.name)
            value.split(",").foreach { labelName =>
--- a/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
+++ b/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
@@ -679,7 +679,6 @@ trait RepositoryViewerControllerBase extends ControllerBase {
      loginUser = loginAccount.userName,
      title = requestBranch,
      content = commitMessage,
-      assignedUserName = None,
      milestoneId = None,
      priorityId = None,
      isPullRequest = true
--- a/src/main/scala/gitbucket/core/controller/api/ApiIssueControllerBase.scala
+++ b/src/main/scala/gitbucket/core/controller/api/ApiIssueControllerBase.scala
@@ -29,9 +29,9 @@ trait ApiIssueControllerBase extends ControllerBase {
    val page = IssueSearchCondition.page(request)
    // TODO: more api spec condition
    val condition = IssueSearchCondition(request)
-    val baseOwner = getAccountByUserName(repository.owner).get
+    //val baseOwner = getAccountByUserName(repository.owner).get

-    val issues: List[(Issue, Account, Option[Account])] =
+    val issues: List[(Issue, Account, List[Account])] =
      searchIssueByApi(
        condition = condition,
        offset = (page - 1) * PullRequestLimit,
@@ -40,12 +40,12 @@ trait ApiIssueControllerBase extends ControllerBase {
      )

    JsonFormat(issues.map {
-      case (issue, issueUser, assignedUser) =>
+      case (issue, issueUser, assigneeUsers) =>
        ApiIssue(
          issue = issue,
          repositoryName = RepositoryName(repository),
          user = ApiUser(issueUser),
-          assignee = assignedUser.map(ApiUser(_)),
+          assignees = assigneeUsers.map(ApiUser(_)),
          labels = getIssueLabels(repository.owner, repository.name, issue.issueId)
            .map(ApiLabel(_, RepositoryName(repository))),
          issue.milestoneId.flatMap { getApiMilestone(repository, _) }
@@ -61,7 +61,8 @@ trait ApiIssueControllerBase extends ControllerBase {
    (for {
      issueId <- params("id").toIntOpt
      issue <- getIssue(repository.owner, repository.name, issueId.toString)
-      users = getAccountsByUserNames(Set(issue.openedUserName) ++ issue.assignedUserName, Set())
+      assigneeUsers = getIssueAssignees(repository.owner, repository.name, issueId)
+      users = getAccountsByUserNames(Set(issue.openedUserName) ++ assigneeUsers.map(_.assigneeUserName), Set())
      openedUser <- users.get(issue.openedUserName)
    } yield {
      JsonFormat(
@@ -69,7 +70,7 @@ trait ApiIssueControllerBase extends ControllerBase {
          issue,
          RepositoryName(repository),
          ApiUser(openedUser),
-          issue.assignedUserName.flatMap(users.get(_)).map(ApiUser(_)),
+          assigneeUsers.flatMap(x => users.get(x.assigneeUserName)).map(ApiUser(_)),
          getIssueLabels(repository.owner, repository.name, issue.issueId).map(ApiLabel(_, RepositoryName(repository))),
          issue.milestoneId.flatMap { getApiMilestone(repository, _) }
        )
@@ -92,7 +93,7 @@ trait ApiIssueControllerBase extends ControllerBase {
          repository,
          data.title,
          data.body,
-          data.assignees.headOption,
+          data.assignees,
          milestone.map(_.milestoneId),
          None,
          data.labels,
@@ -103,7 +104,9 @@ trait ApiIssueControllerBase extends ControllerBase {
            issue,
            RepositoryName(repository),
            ApiUser(loginAccount),
-            issue.assignedUserName.flatMap(getAccountByUserName(_)).map(ApiUser(_)),
+            getIssueAssignees(repository.owner, repository.name, issue.issueId)
+              .flatMap(x => getAccountByUserName(x.assigneeUserName, false))
+              .map(ApiUser.apply),
            getIssueLabels(repository.owner, repository.name, issue.issueId)
              .map(ApiLabel(_, RepositoryName(repository))),
            issue.milestoneId.flatMap { getApiMilestone(repository, _) }
--- a/src/main/scala/gitbucket/core/controller/api/ApiPullRequestControllerBase.scala
+++ b/src/main/scala/gitbucket/core/controller/api/ApiPullRequestControllerBase.scala
@@ -40,7 +40,7 @@ trait ApiPullRequestControllerBase extends ControllerBase {
    val condition = IssueSearchCondition(request)
    val baseOwner = getAccountByUserName(repository.owner).get

-    val issues: List[(Issue, Account, Int, PullRequest, Repository, Account, Option[Account])] =
+    val issues: List[(Issue, Account, Int, PullRequest, Repository, Account, List[Account])] =
      searchPullRequestByApi(
        condition = condition,
        offset = (page - 1) * PullRequestLimit,
@@ -49,7 +49,7 @@ trait ApiPullRequestControllerBase extends ControllerBase {
      )

    JsonFormat(issues.map {
-      case (issue, issueUser, commentCount, pullRequest, headRepo, headOwner, assignee) =>
+      case (issue, issueUser, commentCount, pullRequest, headRepo, headOwner, assignees) =>
        ApiPullRequest(
          issue = issue,
          pullRequest = pullRequest,
@@ -58,7 +58,7 @@ trait ApiPullRequestControllerBase extends ControllerBase {
          user = ApiUser(issueUser),
          labels = getIssueLabels(repository.owner, repository.name, issue.issueId)
            .map(ApiLabel(_, RepositoryName(repository))),
-          assignee = assignee.map(ApiUser.apply),
+          assignees = assignees.map(ApiUser.apply),
          mergedComment = getMergedComment(repository.owner, repository.name, issue.issueId)
        )
    })
@@ -99,7 +99,6 @@ trait ApiPullRequestControllerBase extends ControllerBase {
                      loginUser = context.loginAccount.get.userName,
                      title = createPullReq.title,
                      content = createPullReq.body,
-                      assignedUserName = None,
                      milestoneId = None,
                      priorityId = None,
                      isPullRequest = true
@@ -319,8 +318,8 @@ trait ApiPullRequestControllerBase extends ControllerBase {
      baseOwner <- users.get(repository.owner)
      headOwner <- users.get(pullRequest.requestUserName)
      issueUser <- users.get(issue.openedUserName)
-      assignee = issue.assignedUserName.flatMap { userName =>
-        getAccountByUserName(userName, false)
+      assignees = getIssueAssignees(repository.owner, repository.name, issueId).flatMap { assignedUser =>
+        getAccountByUserName(assignedUser.assigneeUserName, false)
      }
      headRepo <- getRepository(pullRequest.requestUserName, pullRequest.requestRepositoryName)
    } yield {
@@ -332,7 +331,7 @@ trait ApiPullRequestControllerBase extends ControllerBase {
        user = ApiUser(issueUser),
        labels = getIssueLabels(repository.owner, repository.name, issue.issueId)
          .map(ApiLabel(_, RepositoryName(repository))),
-        assignee = assignee.map(ApiUser.apply),
+        assignees = assignees.map(ApiUser.apply),
        mergedComment = getMergedComment(repository.owner, repository.name, issue.issueId)
      )
    }
--- a/src/main/scala/gitbucket/core/model/Issue.scala
+++ b/src/main/scala/gitbucket/core/model/Issue.scala
@@ -27,7 +27,6 @@ trait IssueComponent extends TemplateComponent { self: Profile =>
      with MilestoneTemplate
      with PriorityTemplate {
    val openedUserName = column[String]("OPENED_USER_NAME")
-    val assignedUserName = column[String]("ASSIGNED_USER_NAME")
    val title = column[String]("TITLE")
    val content = column[String]("CONTENT")
    val closed = column[Boolean]("CLOSED")
@@ -42,7 +41,6 @@ trait IssueComponent extends TemplateComponent { self: Profile =>
        openedUserName,
        milestoneId.?,
        priorityId.?,
-        assignedUserName.?,
        title,
        content.?,
        closed,
@@ -62,7 +60,6 @@ case class Issue(
  openedUserName: String,
  milestoneId: Option[Int],
  priorityId: Option[Int],
-  assignedUserName: Option[String],
  title: String,
  content: Option[String],
  closed: Boolean,
--- a/src/main/scala/gitbucket/core/model/IssueAssignee.scala
+++ b/src/main/scala/gitbucket/core/model/IssueAssignee.scala
@@ -0,0 +1,26 @@
+package gitbucket.core.model
+
+trait IssueAssigneeComponent extends TemplateComponent { self: Profile =>
+  import profile.api._
+  import self._
+
+  lazy val IssueAssignees = TableQuery[IssueAssignees]
+
+  class IssueAssignees(tag: Tag) extends Table[IssueAssignee](tag, "ISSUE_ASSIGNEE") with IssueTemplate {
+    val assigneeUserName = column[String]("ASSIGNEE_USER_NAME")
+    def * =
+      (userName, repositoryName, issueId, assigneeUserName)
+        .<>(IssueAssignee.tupled, IssueAssignee.unapply)
+
+    def byPrimaryKey(owner: String, repository: String, issueId: Int, assigneeUserName: String) = {
+      byIssue(owner, repository, issueId) && this.assigneeUserName === assigneeUserName.bind
+    }
+  }
+}
+
+case class IssueAssignee(
+  userName: String,
+  repositoryName: String,
+  issueId: Int,
+  assigneeUserName: String
+)
--- a/src/main/scala/gitbucket/core/model/Profile.scala
+++ b/src/main/scala/gitbucket/core/model/Profile.scala
@@ -74,5 +74,6 @@ trait CoreProfile
    with AccountPreferenceComponent
    with CustomFieldComponent
    with IssueCustomFieldComponent
+    with IssueAssigneeComponent

 object Profile extends CoreProfile
--- a/src/main/scala/gitbucket/core/service/IssueCreationService.scala
+++ b/src/main/scala/gitbucket/core/service/IssueCreationService.scala
@@ -16,7 +16,7 @@ trait IssueCreationService {
    repository: RepositoryInfo,
    title: String,
    body: Option[String],
-    assignee: Option[String],
+    assignees: Seq[String],
    milestoneId: Option[Int],
    priorityId: Option[Int],
    labelNames: Seq[String],
@@ -35,16 +35,19 @@ trait IssueCreationService {
      userName,
      title,
      body,
-      if (manageable) assignee else None,
      if (manageable) milestoneId else None,
      if (manageable) priorityId else None
    )
    val issue: Issue = getIssue(owner, name, issueId.toString).get

-    // insert labels
    if (manageable) {
+      // insert assignees
+      assignees.foreach { assignee =>
+        registerIssueAssignee(owner, name, issueId, assignee)
+      }
+      // insert labels
      val labels = getLabels(owner, name)
-      labelNames.map { labelName =>
+      labelNames.foreach { labelName =>
        labels.find(_.labelName == labelName).map { label =>
          registerIssueLabel(owner, name, issueId, label.labelId)
        }
--- a/src/main/scala/gitbucket/core/service/IssuesService.scala
+++ b/src/main/scala/gitbucket/core/service/IssuesService.scala
@@ -5,7 +5,17 @@ import gitbucket.core.util.StringUtil._
 import gitbucket.core.util.Implicits._
 import gitbucket.core.util.SyntaxSugars._
 import gitbucket.core.controller.Context
-import gitbucket.core.model.{Account, Issue, IssueComment, IssueLabel, Label, PullRequest, Repository, Role}
+import gitbucket.core.model.{
+  Account,
+  Issue,
+  IssueAssignee,
+  IssueComment,
+  IssueLabel,
+  Label,
+  PullRequest,
+  Repository,
+  Role
+}
 import gitbucket.core.model.Profile._
 import gitbucket.core.model.Profile.profile._
 import gitbucket.core.model.Profile.profile.blockingApi._
@@ -118,8 +128,7 @@ trait IssuesService {
  def countIssueGroupByLabels(
    owner: String,
    repository: String,
-    condition: IssueSearchCondition,
-    filterUser: Map[String, String]
+    condition: IssueSearchCondition
  )(implicit s: Session): Map[String, Int] = {

    searchIssueQuery(Seq(owner -> repository), condition.copy(labels = Set.empty), IssueSearchOption.Issues)
@@ -244,20 +253,31 @@ trait IssuesService {
  }

  /** for api
-   * @return (issue, issueUser, assignedUser)
+   * @return (issue, issueUser, Seq(assigneeUsers))
   */
  def searchIssueByApi(condition: IssueSearchCondition, offset: Int, limit: Int, repos: (String, String)*)(
    implicit s: Session
-  ): List[(Issue, Account, Option[Account])] = {
+  ): List[(Issue, Account, List[Account])] = {
    // get issues and comment count and labels
    searchIssueQueryBase(condition, IssueSearchOption.Issues, offset, limit, repos)
      .join(Accounts)
      .on { case t1 ~ t2 ~ i ~ t3 => t3.userName === t1.openedUserName }
+      .joinLeft(IssueAssignees)
+      .on { case t1 ~ t2 ~ i ~ t3 ~ t4 => t4.byIssue(t1.userName, t1.repositoryName, t1.issueId) }
      .joinLeft(Accounts)
-      .on { case t1 ~ t2 ~ i ~ t3 ~ t4 => t4.userName === t1.assignedUserName }
-      .sortBy { case t1 ~ t2 ~ i ~ t3 ~ t4 => i asc }
-      .map { case t1 ~ t2 ~ i ~ t3 ~ t4 => (t1, t3, t4) }
+      .on { case t1 ~ t2 ~ i ~ t3 ~ t4 ~ t5 => t5.userName === t4.map(_.assigneeUserName) }
+      .sortBy { case t1 ~ t2 ~ i ~ t3 ~ t4 ~ t5 => i asc }
+      .map { case t1 ~ t2 ~ i ~ t3 ~ t4 ~ t5 => (t1, t3, t5) }
      .list
+      .groupBy {
+        case (issue, account, assignedUsers) =>
+          (issue, account)
+      }
+      .map {
+        case (_, values) =>
+          (values.head._1, values.head._2, values.flatMap(_._3))
+      }
+      .toList
  }

  /** for api
@@ -265,7 +285,7 @@ trait IssuesService {
   */
  def searchPullRequestByApi(condition: IssueSearchCondition, offset: Int, limit: Int, repos: (String, String)*)(
    implicit s: Session
-  ): List[(Issue, Account, Int, PullRequest, Repository, Account, Option[Account])] = {
+  ): List[(Issue, Account, Int, PullRequest, Repository, Account, List[Account])] = {
    // get issues and comment count and labels
    searchIssueQueryBase(condition, IssueSearchOption.PullRequests, offset, limit, repos)
      .join(PullRequests)
@@ -276,11 +296,30 @@ trait IssuesService {
      .on { case t1 ~ t2 ~ i ~ t3 ~ t4 ~ t5 => t5.userName === t1.openedUserName }
      .join(Accounts)
      .on { case t1 ~ t2 ~ i ~ t3 ~ t4 ~ t5 ~ t6 => t6.userName === t4.userName }
+      .joinLeft(IssueAssignees)
+      .on { case t1 ~ t2 ~ i ~ t3 ~ t4 ~ t5 ~ t6 ~ t7 => t7.byIssue(t1.userName, t1.repositoryName, t1.issueId) }
      .joinLeft(Accounts)
-      .on { case t1 ~ t2 ~ i ~ t3 ~ t4 ~ t5 ~ t6 ~ t7 => t7.userName === t1.assignedUserName }
-      .sortBy { case t1 ~ t2 ~ i ~ t3 ~ t4 ~ t5 ~ t6 ~ t7 => i asc }
-      .map { case t1 ~ t2 ~ i ~ t3 ~ t4 ~ t5 ~ t6 ~ t7 => (t1, t5, t2.commentCount, t3, t4, t6, t7) }
+      .on { case t1 ~ t2 ~ i ~ t3 ~ t4 ~ t5 ~ t6 ~ t7 ~ t8 => t8.userName === t7.map(_.assigneeUserName) }
+      .sortBy { case t1 ~ t2 ~ i ~ t3 ~ t4 ~ t5 ~ t6 ~ t7 ~ t8 => i asc }
+      .map { case t1 ~ t2 ~ i ~ t3 ~ t4 ~ t5 ~ t6 ~ t7 ~ t8 => (t1, t5, t2.commentCount, t3, t4, t6, t8) }
      .list
+      .groupBy {
+        case (issue, openedUser, commentCount, pullRequest, repository, account, assignedUser) =>
+          (issue, openedUser, commentCount, pullRequest, repository, account)
+      }
+      .map {
+        case (_, values) =>
+          (
+            values.head._1,
+            values.head._2,
+            values.head._3,
+            values.head._4,
+            values.head._5,
+            values.head._6,
+            values.flatMap(_._7)
+          )
+      }
+      .toList
  }

  private def searchIssueQueryBase(
@@ -347,7 +386,7 @@ trait IssuesService {
        case _        => t1.closed === true || t1.closed === false
      }).&&(t1.milestoneId.? isEmpty, condition.milestone == Some(None))
        .&&(t1.priorityId.? isEmpty, condition.priority == Some(None))
-        .&&(t1.assignedUserName.? isEmpty, condition.assigned == Some(None))
+        //.&&(t1.assignedUserName.? isEmpty, condition.assigned == Some(None))
        .&&(t1.openedUserName === condition.author.get.bind, condition.author.isDefined) &&
      (searchOption match {
        case IssueSearchOption.Issues       => t1.pullRequest === false
@@ -371,7 +410,13 @@ trait IssuesService {
          condition.priority.flatten.isDefined
        )
        // Assignee filter
-        .&&(t1.assignedUserName === condition.assigned.get.get.bind, condition.assigned.flatten.isDefined)
+        .&&(
+          IssueAssignees filter { a =>
+            a.byIssue(t1.userName, t1.repositoryName, t1.issueId) &&
+            a.assigneeUserName === condition.assigned.get.get.bind
+          } exists,
+          condition.assigned.flatten.isDefined
+        )
        // Label filter
        .&&(
          IssueLabels filter { t2 =>
@@ -396,7 +441,9 @@ trait IssuesService {
        .&&(t1.userName inSetBind condition.groups, condition.groups.nonEmpty)
        // Mentioned filter
        .&&(
-          (t1.openedUserName === condition.mentioned.get.bind) || t1.assignedUserName === condition.mentioned.get.bind ||
+          (t1.openedUserName === condition.mentioned.get.bind) || (IssueAssignees filter { t1 =>
+            t1.byIssue(t1.userName, t1.repositoryName, t1.issueId) && t1.assigneeUserName === condition.mentioned.get.bind
+          } exists) ||
            (IssueComments filter { t2 =>
              (t2.byIssue(t1.userName, t1.repositoryName, t1.issueId)) && (t2.commentedUserName === condition.mentioned.get.bind)
            } exists),
@@ -410,7 +457,6 @@ trait IssuesService {
    loginUser: String,
    title: String,
    content: Option[String],
-    assignedUserName: Option[String],
    milestoneId: Option[Int],
    priorityId: Option[Int],
    isPullRequest: Boolean = false
@@ -427,7 +473,6 @@ trait IssuesService {
          loginUser,
          milestoneId,
          priorityId,
-          assignedUserName,
          title,
          content,
          false,
@@ -542,35 +587,91 @@ trait IssuesService {
      .update(true)
  }

-  def updateAssignedUserName(
+  def getIssueAssignees(owner: String, repository: String, issueId: Int)(
+    implicit s: Session
+  ): List[IssueAssignee] = {
+    IssueAssignees.filter(_.byIssue(owner, repository, issueId)).sortBy(_.assigneeUserName).list
+  }
+
+  def registerIssueAssignee(
    owner: String,
    repository: String,
    issueId: Int,
-    assignedUserName: Option[String],
+    assigneeUserName: String,
    insertComment: Boolean = false
-  )(implicit context: Context, s: Session): Int = {
-    val oldAssigned = getIssue(owner, repository, s"${issueId}").get.assignedUserName
-    val assigned = assignedUserName
+  )(
+    implicit context: Context,
+    s: Session
+  ): Int = {
    val assigner = context.loginAccount.map(_.userName)
    if (insertComment) {
      IssueComments insert IssueComment(
        userName = owner,
        repositoryName = repository,
        issueId = issueId,
-        action = "assign",
+        action = "add_assignee",
        commentedUserName = assigner.getOrElse("Unknown user"),
-        content = s"""${oldAssigned.getOrElse("Not assigned")}:${assigned.getOrElse("Not assigned")}""",
+        content = assigneeUserName,
        registeredDate = currentDate,
        updatedDate = currentDate
      )
    }
    for (issue <- getIssue(owner, repository, issueId.toString); repo <- getRepository(owner, repository)) {
-      PluginRegistry().getIssueHooks.foreach(_.assigned(issue, repo, assigner, assigned, oldAssigned))
+      PluginRegistry().getIssueHooks.foreach(_.assigned(issue, repo, assigner, Some(assigneeUserName), None))
    }
-    Issues
-      .filter(_.byPrimaryKey(owner, repository, issueId))
-      .map(t => (t.assignedUserName ?, t.updatedDate))
-      .update(assignedUserName, currentDate)
+    IssueAssignees insert IssueAssignee(owner, repository, issueId, assigneeUserName)
+  }
+
+  def deleteIssueAssignee(
+    owner: String,
+    repository: String,
+    issueId: Int,
+    assigneeUserName: String,
+    insertComment: Boolean = false
+  )(
+    implicit context: Context,
+    s: Session
+  ): Int = {
+    val assigner = context.loginAccount.map(_.userName)
+    if (insertComment) {
+      IssueComments insert IssueComment(
+        userName = owner,
+        repositoryName = repository,
+        issueId = issueId,
+        action = "delete_assignee",
+        commentedUserName = assigner.getOrElse("Unknown user"),
+        content = assigneeUserName,
+        registeredDate = currentDate,
+        updatedDate = currentDate
+      )
+    }
+
+    // TODO Notify plugins of unassignment as doing in registerIssueAssignee()?
+
+    IssueAssignees filter (_.byPrimaryKey(owner, repository, issueId, assigneeUserName)) delete
+  }
+
+  def deleteAllIssueAssignees(owner: String, repository: String, issueId: Int, insertComment: Boolean = false)(
+    implicit context: Context,
+    s: Session
+  ): Int = {
+    val assigner = context.loginAccount.map(_.userName)
+    if (insertComment) {
+      IssueComments insert IssueComment(
+        userName = owner,
+        repositoryName = repository,
+        issueId = issueId,
+        action = "delete_assign",
+        commentedUserName = assigner.getOrElse("Unknown user"),
+        content = "All assignees",
+        registeredDate = currentDate,
+        updatedDate = currentDate
+      )
+    }
+
+    // TODO Notify plugins of unassignment as doing in registerIssueAssignee()?
+
+    IssueAssignees filter (_.byIssue(owner, repository, issueId)) delete
  }

  def updateMilestoneId(
--- a/src/main/scala/gitbucket/core/service/WebHookService.scala
+++ b/src/main/scala/gitbucket/core/service/WebHookService.scala
@@ -379,8 +379,12 @@ trait WebHookPullRequestService extends WebHookService {
    settings: SystemSettings
  )(implicit s: Session, context: JsonFormat.Context): Unit = {
    callWebHookOf(repository.owner, repository.name, WebHook.Issues, settings) {
+      val assigneeUsers = getIssueAssignees(repository.owner, repository.name, issue.issueId)
      val users =
-        getAccountsByUserNames(Set(repository.owner, issue.openedUserName) ++ issue.assignedUserName, Set(sender))
+        getAccountsByUserNames(
+          Set(repository.owner, issue.openedUserName) ++ assigneeUsers.map(_.assigneeUserName),
+          Set(sender)
+        )
      for {
        repoOwner <- users.get(repository.owner)
        issueUser <- users.get(issue.openedUserName)
@@ -393,7 +397,7 @@ trait WebHookPullRequestService extends WebHookService {
            issue,
            RepositoryName(repository),
            ApiUser(issueUser),
-            issue.assignedUserName.flatMap(users.get(_)).map(ApiUser(_)),
+            assigneeUsers.flatMap(x => users.get(x.assigneeUserName)).map(ApiUser(_)),
            getIssueLabels(repository.owner, repository.name, issue.issueId)
              .map(ApiLabel(_, RepositoryName(repository))),
            getApiMilestone(repository, issue.milestoneId getOrElse (0))
@@ -415,16 +419,15 @@ trait WebHookPullRequestService extends WebHookService {
    callWebHookOf(repository.owner, repository.name, WebHook.PullRequest, settings) {
      for {
        (issue, pullRequest) <- getPullRequest(repository.owner, repository.name, issueId)
+        assignees = getIssueAssignees(repository.owner, repository.name, issueId)
        users = getAccountsByUserNames(
-          Set(repository.owner, pullRequest.requestUserName, issue.openedUserName),
+          Set(repository.owner, pullRequest.requestUserName, issue.openedUserName) ++ assignees.map(_.assigneeUserName),
          Set(sender)
        )
        baseOwner <- users.get(repository.owner)
        headOwner <- users.get(pullRequest.requestUserName)
        issueUser <- users.get(issue.openedUserName)
-        assignee = issue.assignedUserName.flatMap { userName =>
-          getAccountByUserName(userName, false)
-        }
+        assigneeUsers = assignees.flatMap(x => users.get(x.assigneeUserName))
        headRepo <- getRepository(pullRequest.requestUserName, pullRequest.requestRepositoryName)
        labels = getIssueLabels(repository.owner, repository.name, issue.issueId)
          .map(ApiLabel(_, RepositoryName(repository)))
@@ -433,7 +436,7 @@ trait WebHookPullRequestService extends WebHookService {
          action = action,
          issue = issue,
          issueUser = issueUser,
-          assignee = assignee,
+          assignees = assigneeUsers,
          pullRequest = pullRequest,
          headRepository = headRepo,
          headOwner = headOwner,
@@ -481,8 +484,8 @@ trait WebHookPullRequestService extends WebHookService {
        requestRepository.name,
        requestBranch
      )
-      assignee = issue.assignedUserName.flatMap { userName =>
-        getAccountByUserName(userName, false)
+      assignees = getIssueAssignees(requestRepository.owner, requestRepository.name, issue.issueId).flatMap { x =>
+        getAccountByUserName(x.assigneeUserName, false)
      }
      baseRepo <- getRepository(pullRequest.userName, pullRequest.repositoryName)
      labels = getIssueLabels(pullRequest.userName, pullRequest.repositoryName, issue.issueId)
@@ -492,7 +495,7 @@ trait WebHookPullRequestService extends WebHookService {
        action = action,
        issue = issue,
        issueUser = issueUser,
-        assignee = assignee,
+        assignees = assignees,
        pullRequest = pullRequest,
        headRepository = requestRepository,
        headOwner = headOwner,
@@ -522,15 +525,17 @@ trait WebHookPullRequestReviewCommentService extends WebHookService {
  )(implicit s: Session, c: JsonFormat.Context): Unit = {
    import WebHookService._
    callWebHookOf(repository.owner, repository.name, WebHook.PullRequestReviewComment, settings) {
+      val assignees = getIssueAssignees(repository.owner, pullRequest.requestUserName, issue.issueId)
      val users =
-        getAccountsByUserNames(Set(repository.owner, pullRequest.requestUserName, issue.openedUserName), Set(sender))
+        getAccountsByUserNames(
+          Set(repository.owner, pullRequest.requestUserName, issue.openedUserName) ++ assignees.map(_.assigneeUserName),
+          Set(sender)
+        )
      for {
        baseOwner <- users.get(repository.owner)
        headOwner <- users.get(pullRequest.requestUserName)
        issueUser <- users.get(issue.openedUserName)
-        assignee = issue.assignedUserName.flatMap { userName =>
-          getAccountByUserName(userName, false)
-        }
+        assigneeUsers = assignees.flatMap(x => users.get(x.assigneeUserName))
        headRepo <- getRepository(pullRequest.requestUserName, pullRequest.requestRepositoryName)
        labels = getIssueLabels(pullRequest.userName, pullRequest.repositoryName, issue.issueId)
          .map(ApiLabel(_, RepositoryName(pullRequest.userName, pullRequest.repositoryName)))
@@ -540,7 +545,7 @@ trait WebHookPullRequestReviewCommentService extends WebHookService {
          comment = comment,
          issue = issue,
          issueUser = issueUser,
-          assignee = assignee,
+          assignees = assigneeUsers,
          pullRequest = pullRequest,
          headRepository = headRepo,
          headOwner = headOwner,
@@ -569,14 +574,17 @@ trait WebHookIssueCommentService extends WebHookPullRequestService {
    callWebHookOf(repository.owner, repository.name, WebHook.IssueComment, settings) {
      for {
        issueComment <- getComment(repository.owner, repository.name, issueCommentId.toString())
+        assignees = getIssueAssignees(repository.owner, repository.name, issue.issueId)
        users = getAccountsByUserNames(
-          Set(issue.openedUserName, repository.owner, issueComment.commentedUserName) ++ issue.assignedUserName,
+          Set(issue.openedUserName, repository.owner, issueComment.commentedUserName) ++ assignees.map(
+            _.assigneeUserName
+          ),
          Set(sender)
        )
        issueUser <- users.get(issue.openedUserName)
        repoOwner <- users.get(repository.owner)
        commenter <- users.get(issueComment.commentedUserName)
-        assignedUser = issue.assignedUserName.flatMap(users.get(_))
+        assigneeUsers = assignees.flatMap(x => users.get(x.assigneeUserName))
        labels = getIssueLabels(repository.owner, repository.name, issue.issueId)
        milestone = getApiMilestone(repository, issue.milestoneId getOrElse (0))
      } yield {
@@ -587,7 +595,7 @@ trait WebHookIssueCommentService extends WebHookPullRequestService {
          commentUser = commenter,
          repository = repository,
          repositoryUser = repoOwner,
-          assignedUser = assignedUser,
+          assignees = assigneeUsers,
          sender = sender,
          labels = labels,
          milestone = milestone
@@ -710,7 +718,7 @@ object WebHookService {
      action: String,
      issue: Issue,
      issueUser: Account,
-      assignee: Option[Account],
+      assignees: List[Account],
      pullRequest: PullRequest,
      headRepository: RepositoryInfo,
      headOwner: Account,
@@ -731,7 +739,7 @@ object WebHookService {
        baseRepo = baseRepoPayload,
        user = ApiUser(issueUser),
        labels = labels,
-        assignee = assignee.map(ApiUser.apply),
+        assignees = assignees.map(ApiUser.apply),
        mergedComment = mergedComment
      )

@@ -762,7 +770,7 @@ object WebHookService {
      commentUser: Account,
      repository: RepositoryInfo,
      repositoryUser: Account,
-      assignedUser: Option[Account],
+      assignees: List[Account],
      sender: Account,
      labels: List[Label],
      milestone: Option[ApiMilestone]
@@ -774,7 +782,7 @@ object WebHookService {
          issue,
          RepositoryName(repository),
          ApiUser(issueUser),
-          assignedUser.map(ApiUser(_)),
+          assignees.map(ApiUser(_)),
          labels.map(ApiLabel(_, RepositoryName(repository))),
          milestone
        ),
@@ -799,7 +807,7 @@ object WebHookService {
      comment: CommitComment,
      issue: Issue,
      issueUser: Account,
-      assignee: Option[Account],
+      assignees: List[Account],
      pullRequest: PullRequest,
      headRepository: RepositoryInfo,
      headOwner: Account,
@@ -828,7 +836,7 @@ object WebHookService {
          baseRepo = baseRepoPayload,
          user = ApiUser(issueUser),
          labels = labels,
-          assignee = assignee.map(ApiUser.apply),
+          assignees = assignees.map(ApiUser.apply),
          mergedComment = mergedComment
        ),
        repository = baseRepoPayload,
--- a/src/main/twirl/gitbucket/core/dashboard/issueslist.scala.html
+++ b/src/main/twirl/gitbucket/core/dashboard/issueslist.scala.html
@@ -33,9 +33,11 @@
            <span class="label-color small" style="background-color: #@label.color; color: #@label.fontColor; padding-left: 4px; padding-right: 4px">@label.labelName</span>
          }
          <span class="pull-right muted">
+            @*
            @issue.assignedUserName.map { userName =>
              @helpers.avatar(userName, 20, tooltip = true)
            }
+            *@
            @if(commentCount > 0){
              <a href="@context.path/@issue.userName/@issue.repositoryName/issues/@issue.issueId" class="issue-comment-count">
                <i class="octicon octicon-comment active"></i> @commentCount
--- a/src/main/twirl/gitbucket/core/issues/commentlist.scala.html
+++ b/src/main/twirl/gitbucket/core/issues/commentlist.scala.html
@@ -200,7 +200,7 @@
            <span class="discussion-item-icon"><i class="octicon octicon-tag"></i></span>
            @helpers.avatarLink(comment.commentedUserName, 16)
            @helpers.user(comment.commentedUserName, styleClass="username strong")
-            add the <code>@comment.content</code> label
+            added the <code>@comment.content</code> label
            @gitbucket.core.helper.html.datetimeago(comment.registeredDate)
          </div>
        </div>
@@ -222,7 +222,7 @@
            <span class="discussion-item-icon"><i class="octicon octicon-flame"></i></span>
            @helpers.avatarLink(comment.commentedUserName, 16)
            @helpers.user(comment.commentedUserName, styleClass="username strong")
-            change priority from <code>@comment.content.split(":")(0)</code> to <code>@comment.content.split(":")(1)</code>
+            changed priority from <code>@comment.content.split(":")(0)</code> to <code>@comment.content.split(":")(1)</code>
            @gitbucket.core.helper.html.datetimeago(comment.registeredDate)
          </div>
        </div>
@@ -233,18 +233,40 @@
            <span class="discussion-item-icon"><i class="octicon octicon-milestone"></i></span>
            @helpers.avatarLink(comment.commentedUserName, 16)
            @helpers.user(comment.commentedUserName, styleClass="username strong")
-            change milestone from <code>@comment.content.split(":")(0)</code> to <code>@comment.content.split(":")(1)</code>
+            changed milestone from <code>@comment.content.split(":")(0)</code> to <code>@comment.content.split(":")(1)</code>
            @gitbucket.core.helper.html.datetimeago(comment.registeredDate)
          </div>
        </div>
      }
-      case "assign" => {
+      case "assign" => { @* for backward compatibility *@
        <div class="discussion-item discussion-item-assign">
          <div class="discussion-item-header">
            <span class="discussion-item-icon"><i class="octicon octicon-person"></i></span>
            @helpers.avatarLink(comment.commentedUserName, 16)
            @helpers.user(comment.commentedUserName, styleClass="username strong")
-            change assignee from <code>@comment.content.split(":")(0)</code> to <code>@comment.content.split(":")(1)</code>
+            changed assignee from <code>@comment.content.split(":")(0)</code> to <code>@comment.content.split(":")(1)</code>
+            @gitbucket.core.helper.html.datetimeago(comment.registeredDate)
+          </div>
+        </div>
+      }
+      case "add_assignee" => {
+        <div class="discussion-item discussion-item-assign">
+          <div class="discussion-item-header">
+            <span class="discussion-item-icon"><i class="octicon octicon-person"></i></span>
+            @helpers.avatarLink(comment.commentedUserName, 16)
+            @helpers.user(comment.commentedUserName, styleClass="username strong")
+            assigned <code>@comment.content</code>
+            @gitbucket.core.helper.html.datetimeago(comment.registeredDate)
+          </div>
+        </div>
+      }
+      case "delete_assignee" => {
+        <div class="discussion-item discussion-item-assign">
+          <div class="discussion-item-header">
+            <span class="discussion-item-icon"><i class="octicon octicon-person"></i></span>
+            @helpers.avatarLink(comment.commentedUserName, 16)
+            @helpers.user(comment.commentedUserName, styleClass="username strong")
+            unassigned <code>@comment.content</code></code>
            @gitbucket.core.helper.html.datetimeago(comment.registeredDate)
          </div>
        </div>
@@ -255,7 +277,7 @@
            <span class="discussion-item-icon"><i class="octicon octicon-pencil"></i></span>
            @helpers.avatar(comment.commentedUserName, 16)
            @helpers.user(comment.commentedUserName, styleClass="username strong")
-            change title from <code>@convertLineSeparator(comment.content, "LF").split("\n")(0)</code> to <code>@convertLineSeparator(comment.content, "LF").split("\n")(1)</code>
+            changed title from <code>@convertLineSeparator(comment.content, "LF").split("\n")(0)</code> to <code>@convertLineSeparator(comment.content, "LF").split("\n")(1)</code>
            @gitbucket.core.helper.html.datetimeago(comment.registeredDate)
          </div>
        </div>
@@ -266,7 +288,7 @@
            <span class="discussion-item-icon"><i class="octicon octicon-pencil"></i></span>
            @helpers.avatar(comment.commentedUserName, 16)
            @helpers.user(comment.commentedUserName, styleClass="username strong")
-            change base branch from <code>@convertLineSeparator(comment.content, "LF").split("\n")(0)</code> to <code>@convertLineSeparator(comment.content, "LF").split("\n")(1)</code>
+            changed base branch from <code>@convertLineSeparator(comment.content, "LF").split("\n")(0)</code> to <code>@convertLineSeparator(comment.content, "LF").split("\n")(1)</code>
            @gitbucket.core.helper.html.datetimeago(comment.registeredDate)
          </div>
        </div>
@@ -328,9 +350,9 @@
 $(function(){
@if(issue.isDefined){
  $('.issue-comment-box i.octicon-pencil').click(function(){
-    var id  = $(this).closest('a').data('comment-id');
-    var url = '@helpers.url(repository)/issue_comments/_data/' + id;
-    var $content = $('#commentContent-' + id);
+    let id  = $(this).closest('a').data('comment-id');
+    let url = '@helpers.url(repository)/issue_comments/_data/' + id;
+    let $content = $('#commentContent-' + id);

    if(!id){
      id  = $(this).closest('a').data('issue-id');
@@ -345,7 +367,7 @@ $(function(){
  });
  $('.issue-comment-box i.octicon-x').click(function(){
    if(confirm('Are you sure you want to delete this?')) {
-      var id = $(this).closest('a').data('comment-id');
+      const id = $(this).closest('a').data('comment-id');
      $.post('@helpers.url(repository)/issue_comments/delete/' + id, function(data){
        if(data > 0) {
          $('#comment-' + id).remove();
@@ -356,9 +378,9 @@ $(function(){
  });
 }
  $(document).on('click', '.commit-comment-box i.octicon-pencil', function(){
-    var id  = $(this).closest('a').data('comment-id');
-    var url = '@helpers.url(repository)/commit_comments/_data/' + id;
-    var $content = $('.commit-commentContent-' + id, $(this).closest('.commit-comment-box'));
+    const id  = $(this).closest('a').data('comment-id');
+    const url = '@helpers.url(repository)/commit_comments/_data/' + id;
+    const $content = $('.commit-commentContent-' + id, $(this).closest('.commit-comment-box'));

    $.get(url, { dataType : 'html' }, function(data){
      $content.empty().html(data);
@@ -369,14 +391,14 @@ $(function(){

  $(document).on('click', '.commit-comment-box i.octicon-x', function(){
    if(confirm('Are you sure you want to delete this?')) {
-      var id = $(this).closest('a').data('comment-id');
+      const id = $(this).closest('a').data('comment-id');
      $.post('@helpers.url(repository)/commit_comments/delete/' + id,
      function(data){
        if(data > 0) {
-          var comment = $('.commit-comment-' + id);
+          const comment = $('.commit-comment-' + id);

          // diff view
-          var tr = comment.closest('.not-diff');
+          const tr = comment.closest('.not-diff');
          if(tr.length > 0){
            if(tr.prev('.not-diff').length == 0){
              tr.next('.not-diff:has(.reply-comment)').remove();
@@ -385,7 +407,7 @@ $(function(){
          }

          // comment list view
-          var panel = comment.closest('div.panel:has(.commit-comment-box)');
+          const panel = comment.closest('div.panel:has(.commit-comment-box)');
          if(panel.length > 0){
            comment.parent('.commit-comment-box').remove();
            if(panel.has('.commit-comment-box').length == 0){
@@ -401,7 +423,7 @@ $(function(){
  });

  $('div[class*=commit-commentContent-]').on('click', ':checkbox', function(ev){
-    var $commentContent = $(ev.target).parents('div[class*=commit-commentContent-]'),
+    const $commentContent = $(ev.target).parents('div[class*=commit-commentContent-]'),
        commentId = $commentContent.attr('class').match(/commit-commentContent-.+/)[0].replace(/commit-commentContent-/, ''),
        checkboxes = $commentContent.find(':checkbox');
    $.get('@helpers.url(repository)/commit_comments/_data/' + commentId, { dataType : 'html' },
@@ -421,9 +443,9 @@ $(function(){
    );
  });

-  @if(issue.isDefined){
+@if(issue.isDefined){
  $('#issueContent').on('click', ':checkbox', function(ev){
-    var checkboxes = $('#issueContent :checkbox');
+    const checkboxes = $('#issueContent :checkbox');
    $.get('@helpers.url(repository)/issues/_data/@issue.get.issueId', { dataType : 'html' },
      function(responseContent){
        $.ajax({
@@ -439,7 +461,7 @@ $(function(){
  });

  $('div[id^=commentContent-]').on('click', ':checkbox', function(ev){
-    var $commentContent = $(ev.target).parents('div[id^=commentContent-]'),
+    const $commentContent = $(ev.target).parents('div[id^=commentContent-]'),
        commentId = $commentContent.attr('id').replace(/commentContent-/, ''),
        checkboxes = $commentContent.find(':checkbox');
    $.get('@helpers.url(repository)/issue_comments/_data/' + commentId, { dataType : 'html' },
@@ -455,9 +477,7 @@ $(function(){
      }
    );
  });
-
-  }
-
+}
 });
 </script>
 }
--- a/src/main/twirl/gitbucket/core/issues/create.scala.html
+++ b/src/main/twirl/gitbucket/core/issues/create.scala.html
@@ -36,6 +36,7 @@
            issue = None,
            comments = Nil,
            issueLabels = Nil,
+            issueAssignees = Nil,
            collaborators = collaborators,
            milestones = milestones.map(x => (x, 0, 0)),
            priorities= priorities,
--- a/src/main/twirl/gitbucket/core/issues/issue.scala.html
+++ b/src/main/twirl/gitbucket/core/issues/issue.scala.html
@@ -1,6 +1,7 @@
@(issue: gitbucket.core.model.Issue,
  comments: List[gitbucket.core.model.IssueComment],
  issueLabels: List[gitbucket.core.model.Label],
+  issueAssignees: List[gitbucket.core.model.IssueAssignee],
  collaborators: List[String],
  milestones: List[(gitbucket.core.model.Milestone, Int, Int)],
  priorities: List[gitbucket.core.model.Priority],
@@ -61,6 +62,7 @@
          issue = Some(issue),
          comments = comments,
          issueLabels = issueLabels,
+          issueAssignees = issueAssignees,
          collaborators = collaborators,
          milestones = milestones,
          priorities = priorities,
--- a/src/main/twirl/gitbucket/core/issues/issueinfo.scala.html
+++ b/src/main/twirl/gitbucket/core/issues/issueinfo.scala.html
@@ -2,6 +2,7 @@
@(issue: Option[gitbucket.core.model.Issue],
  comments: List[gitbucket.core.model.Comment],
  issueLabels: List[gitbucket.core.model.Label],
+  issueAssignees: List[gitbucket.core.model.IssueAssignee],
  collaborators: List[String],
  milestones: List[(gitbucket.core.model.Milestone, Int, Int)],
  priorities: List[gitbucket.core.model.Priority],
@@ -127,11 +128,10 @@
  @if(isManageable){
    <div class="pull-right">
      @gitbucket.core.helper.html.dropdown("Edit", right = true, filter = ("assignee", "Filter Assignee")) {
-        <li><a href="javascript:void(0);" class="assign" data-name=""><i class="octicon octicon-x"></i> Clear assignee</a></li>
        @collaborators.map { collaborator =>
          <li>
-            <a href="javascript:void(0);" class="assign" data-name="@collaborator">
-              @gitbucket.core.helper.html.checkicon(issue.exists(_.assignedUserName.exists(_ == collaborator)))@helpers.avatar(collaborator, 20) @collaborator
+            <a href="javascript:void(0);" class="toggle-assign" data-name="@collaborator">
+              @gitbucket.core.helper.html.checkicon(issueAssignees.exists(_.assigneeUserName == collaborator))@helpers.avatar(collaborator, 20) @collaborator
            </a>
          </li>
        }
@@ -140,14 +140,15 @@
  }
 </div>
 <span id="label-assigned">
-  @issue.flatMap(_.assignedUserName).map { userName =>
-    @helpers.avatarLink(userName, 20) @helpers.user(userName, styleClass="username strong small")
-  }.getOrElse{
-    <span class="muted small">No one</span>
+  @issueAssignees.map { asignee =>
+    @helpers.avatarLink(asignee.assigneeUserName, 20) @helpers.user(asignee.assigneeUserName, styleClass="username strong small")
+  }
+  @if(issueAssignees.isEmpty) {
+    <span class="muted small">No one assigned</span>
  }
 </span>
@if(issue.isEmpty){
-  <input type="hidden" name="assignedUserName" value=""/>
+  <input type="hidden" name="assigneeUserNames" value=""/>
 }

@customFields.map { case (field, value) =>
@@ -188,7 +189,7 @@
 $(function(){
@issue.map { issue =>
  $('a.toggle-label').click(function(){
-    const path = switchLabel($(this));
+    const path = switchToggleOptions($(this));
    $.post('@helpers.url(repository)/issues/@issue.issueId/label/' + path,
      { labelId : $(this).data('label-id') },
      function(data){
@@ -223,19 +224,25 @@ $(function(){
    );
  });

-  $('a.assign').click(function(){
-    const $this = $(this);
-    const userName = $this.data('name');
-    $.post('@helpers.url(repository)/issues/@issue.issueId/assign',
-      { assignedUserName: userName },
-      function(){
-        displayAssignee($this, userName);
+  $('a.toggle-assign').click(function(){
+    const path = switchToggleOptions($(this));
+    $.post('@helpers.url(repository)/issues/@issue.issueId/assignee/' + path,
+      { assigneeUserName : $(this).data('name') },
+      function(data){
+        const assignees = Array();
+        $('a.toggle-assign').each(function(i, e){
+          if($(e).children('i').hasClass('octicon-check') == true){
+            assignees.push($(e).text().trim());
+          }
+        });
+        displayAssignee(assignees);
      }
    );
+    return false;
  });
 }.getOrElse {
  $('a.toggle-label').click(function(){
-    switchLabel($(this));
+    switchToggleOptions($(this));
    const labelNames = Array();
    $('a.toggle-label').each(function(i, e){
      if($(e).children('i').hasClass('octicon-check') == true){
@@ -269,15 +276,20 @@ $(function(){
    $('input[name=priorityId]').val(priorityId);
  });

-  $('a.assign').click(function(){
-    const $this = $(this);
-    const userName = $this.data('name');
-    displayAssignee($this, userName);
-    $('input[name=assignedUserName]').val(userName);
+  $('a.toggle-assign').click(function(){
+    switchToggleOptions($(this));
+    const assignees = Array();
+    $('a.toggle-assign').each(function(i, e){
+      if($(e).children('i').hasClass('octicon-check') == true){
+        assignees.push($(e).text().trim());
+      }
+    });
+    $('input[name=assigneeUserNames]').val(assignees.join(','));
+    displayAssignee(assignees);
  });
 }

-  function switchLabel($this){
+  function switchToggleOptions($this){
    const i = $this.children('i');
    if(i.hasClass('octicon-check')){
      i.removeClass('octicon-check');
@@ -320,15 +332,18 @@ $(function(){
    }
  }

-  function displayAssignee($this, userName){
+  function displayAssignee(assignees){
    $('a.assign i.octicon-check').removeClass('octicon-check');
-    if(userName == ''){
-      $('#label-assigned').html($('<span class="muted small">').text('No one'));
+    if(assignees.length == 0){
+      $('#label-assigned').html($('<span class="muted small">').text('No one assigned'));
    } else {
-      $('#label-assigned').empty()
-        .append($this.find('img.avatar-mini').clone(false)).append(' ')
-        .append($('<a class="username strong small">').attr('href', '@context.path/' + userName).text(userName));
-      $('a.assign[data-name=' + jqSelectorEscape(userName.toString()) + '] i').addClass('octicon-check');
+      $('#label-assigned').empty();
+      for (const userName of assignees) {
+        $('#label-assigned').append($('<div>').append(
+            $('a.toggle-assign').parent().find("img.avatar-mini[alt='@@" + userName + "']").clone(false),
+            ' ',
+            $('<a class="username strong small">').attr('href', '@context.path/' + userName).text(userName)));
+      }
    }
  }
 });
--- a/src/main/twirl/gitbucket/core/issues/listparts.scala.html
+++ b/src/main/twirl/gitbucket/core/issues/listparts.scala.html
@@ -230,9 +230,11 @@
            <span class="label-color small" style="background-color: #@label.color; color: #@label.fontColor; padding-left: 4px; padding-right: 4px">@label.labelName</span>
          }
          <span class="pull-right small">
+            @*
            @issue.assignedUserName.map { userName =>
              @helpers.avatar(userName, 20, tooltip = true)
            }
+            *@
            @if(commentCount > 0){
              <a href="@context.path/@issue.userName/@issue.repositoryName/issues/@issue.issueId" class="issue-comment-count">
                <i class="octicon octicon-comment active"></i> @commentCount
--- a/src/main/twirl/gitbucket/core/issues/milestones/listparts.scala.html
+++ b/src/main/twirl/gitbucket/core/issues/milestones/listparts.scala.html
@@ -90,9 +90,11 @@
            <span class="label-color small" style="background-color: #@label.color; color: #@label.fontColor; padding-left: 4px; padding-right: 4px">@label.labelName</span>
          }
          <span class="pull-right small">
+            @*
            @issue.assignedUserName.map { userName =>
              @helpers.avatar(userName, 20, tooltip = true)
            }
+            *@
            @if(commentCount > 0){
              <a href="@context.path/@issue.userName/@issue.repositoryName/issues/@issue.issueId" class="issue-comment-count">
                <i class="octicon octicon-comment active"></i> @commentCount
--- a/src/main/twirl/gitbucket/core/pulls/compare.scala.html
+++ b/src/main/twirl/gitbucket/core/pulls/compare.scala.html
@@ -106,6 +106,7 @@
                issue = None,
                comments = Nil,
                issueLabels = Nil,
+                issueAssignees = Nil,
                collaborators = collaborators,
                milestones = milestones.map((_, 0, 0)),
                priorities = priorities,
--- a/src/main/twirl/gitbucket/core/pulls/conversation.scala.html
+++ b/src/main/twirl/gitbucket/core/pulls/conversation.scala.html
@@ -4,6 +4,7 @@
  comments: Seq[gitbucket.core.model.Comment],
  changedFileSize: Int,
  issueLabels: List[gitbucket.core.model.Label],
+  issueAsignees: List[gitbucket.core.model.IssueAssignee],
  collaborators: List[String],
  milestones: List[(gitbucket.core.model.Milestone, Int, Int)],
  priorities: List[gitbucket.core.model.Priority],
@@ -55,6 +56,7 @@
      Some(issue),
      comments.toList,
      issueLabels,
+      issueAsignees,
      collaborators,
      milestones,
      priorities,
--- a/src/test/scala/gitbucket/core/api/ApiSpecModels.scala
+++ b/src/test/scala/gitbucket/core/api/ApiSpecModels.scala
@@ -116,7 +116,6 @@ object ApiSpecModels {
    openedUserName = "bear",
    milestoneId = None,
    priorityId = None,
-    assignedUserName = None,
    title = "Found a bug",
    content = Some("I'm having a problem with this."),
    closed = false,
@@ -226,7 +225,7 @@ object ApiSpecModels {
    issue = issue,
    repositoryName = repo1Name,
    user = apiUser,
-    assignee = Some(apiUser),
+    assignees = List(apiUser),
    labels = List(apiLabel),
    milestone = Some(apiMilestone)
  )
@@ -235,7 +234,7 @@ object ApiSpecModels {
    issue = issue,
    repositoryName = repo1Name,
    user = apiUser,
-    assignee = None,
+    assignees = List.empty,
    labels = List(apiLabel),
    milestone = Some(apiMilestone)
  )
@@ -244,7 +243,7 @@ object ApiSpecModels {
    issue = issuePR,
    repositoryName = repo1Name,
    user = apiUser,
-    assignee = Some(apiUser),
+    assignees = List(apiUser),
    labels = List(apiLabel),
    milestone = Some(apiMilestone)
  )
@@ -272,7 +271,7 @@ object ApiSpecModels {
    baseRepo = apiRepository,
    user = apiUser,
    labels = List(apiLabel),
-    assignee = Some(apiUser),
+    assignees = List(apiUser),
    mergedComment = Some((issueComment, account))
  )

@@ -540,7 +539,7 @@ object ApiSpecModels {
       |"number":1347,
       |"title":"Found a bug",
       |"user":$jsonUser,
-       |"assignee":$jsonUser,
+       |"assignees":[$jsonUser],
       |"labels":[$jsonLabel],
       |"state":"open",
       |"created_at":"2011-04-14T16:00:49Z",
@@ -548,7 +547,7 @@ object ApiSpecModels {
       |"body":"I'm having a problem with this.",
       |"milestone":$jsonMilestone,
       |"id":0,
-       |"assignees":[$jsonUser],
+       |"assignee":$jsonUser,
       |"comments_url":"http://gitbucket.exmple.com/api/v3/repos/octocat/Hello-World/issues/1347/comments",
       |"html_url":"http://gitbucket.exmple.com/octocat/Hello-World/issues/1347"
       |}""".stripMargin
@@ -557,6 +556,7 @@ object ApiSpecModels {
       |"number":1347,
       |"title":"Found a bug",
       |"user":$jsonUser,
+       |"assignees":[],
       |"labels":[$jsonLabel],
       |"state":"open",
       |"created_at":"2011-04-14T16:00:49Z",
@@ -564,7 +564,6 @@ object ApiSpecModels {
       |"body":"I'm having a problem with this.",
       |"milestone":$jsonMilestone,
       |"id":0,
-       |"assignees":[],
       |"comments_url":"http://gitbucket.exmple.com/api/v3/repos/octocat/Hello-World/issues/1347/comments",
       |"html_url":"http://gitbucket.exmple.com/octocat/Hello-World/issues/1347"
       |}""".stripMargin
@@ -573,7 +572,7 @@ object ApiSpecModels {
       |"number":1347,
       |"title":"new-feature",
       |"user":$jsonUser,
-       |"assignee":$jsonUser,
+       |"assignees":[$jsonUser],
       |"labels":[$jsonLabel],
       |"state":"closed",
       |"created_at":"2011-04-14T16:00:49Z",
@@ -581,12 +580,12 @@ object ApiSpecModels {
       |"body":"Please pull these awesome changes",
       |"milestone":$jsonMilestone,
       |"id":0,
-       |"assignees":[$jsonUser],
+       |"assignee":$jsonUser,
       |"comments_url":"http://gitbucket.exmple.com/api/v3/repos/octocat/Hello-World/issues/1347/comments",
       |"html_url":"http://gitbucket.exmple.com/octocat/Hello-World/pull/1347",
       |"pull_request":{
-         |"url":"http://gitbucket.exmple.com/api/v3/repos/octocat/Hello-World/pulls/1347",
-         |"html_url":"http://gitbucket.exmple.com/octocat/Hello-World/pull/1347"}
+       |"url":"http://gitbucket.exmple.com/api/v3/repos/octocat/Hello-World/pulls/1347",
+       |"html_url":"http://gitbucket.exmple.com/octocat/Hello-World/pull/1347"}
       |}""".stripMargin

  val jsonPullRequest = s"""{
@@ -603,9 +602,10 @@ object ApiSpecModels {
       |"body":"Please pull these awesome changes",
       |"user":$jsonUser,
       |"labels":[$jsonLabel],
-       |"assignee":$jsonUser,
+       |"assignees":[$jsonUser],
       |"draft":true,
       |"id":0,
+       |"assignee":$jsonUser,
       |"html_url":"http://gitbucket.exmple.com/octocat/Hello-World/pull/1347",
       |"url":"http://gitbucket.exmple.com/api/v3/repos/octocat/Hello-World/pulls/1347",
       |"commits_url":"http://gitbucket.exmple.com/api/v3/repos/octocat/Hello-World/pulls/1347/commits",
--- a/src/test/scala/gitbucket/core/service/ServiceSpecBase.scala
+++ b/src/test/scala/gitbucket/core/service/ServiceSpecBase.scala
@@ -142,7 +142,6 @@ trait ServiceSpecBase {
      loginUser = loginUser,
      title = "issue title",
      content = None,
-      assignedUserName = None,
      milestoneId = None,
      priorityId = None,
      isPullRequest = true
--- a/src/test/scala/gitbucket/core/service/WebHookJsonFormatSpec.scala
+++ b/src/test/scala/gitbucket/core/service/WebHookJsonFormatSpec.scala
@@ -91,7 +91,7 @@ class WebHookJsonFormatSpec extends AnyFunSuite {
      action = "closed",
      issue = issuePR,
      issueUser = account,
-      assignee = Some(account),
+      assignees = List(account),
      pullRequest = pullRequest,
      headRepository = repositoryInfo,
      headOwner = account,
@@ -119,7 +119,7 @@ class WebHookJsonFormatSpec extends AnyFunSuite {
      commentUser = account,
      repository = repositoryInfo,
      repositoryUser = account,
-      assignedUser = Some(account),
+      assignees = List(account),
      sender = account,
      labels = List(label),
      milestone = Some(apiMilestone)
@@ -140,7 +140,7 @@ class WebHookJsonFormatSpec extends AnyFunSuite {
      comment = commitComment,
      issue = issuePR,
      issueUser = account,
-      assignee = Some(account),
+      assignees = List(account),
      pullRequest = pullRequest,
      headRepository = repositoryInfo,
      headOwner = account,
--- a/src/test/scala/gitbucket/core/view/PaginationSpec.scala
+++ b/src/test/scala/gitbucket/core/view/PaginationSpec.scala
@@ -1,6 +1,5 @@
 package gitbucket.core.view

-import gitbucket.core.util.SyntaxSugars
 import org.scalatest.funspec.AnyFunSpec

 class PaginationSpec extends AnyFunSpec {