Merge branch 'multiple_assignees_review' into multiple-assignees-fe-sidebar

app/assets/javascripts/boards/components/issue_card_inner.js

@@ -20,6 +20,7 @@ import eventHub from '../eventhub';
       list: {
         type: Object,
         required: false,
+        default: () => ({}),
       },
       rootPath: {
         type: String,
@@ -31,7 +32,67 @@ import eventHub from '../eventhub';
         default: false,
       },
     },
+    data() {
+      return {
+        limitBeforeCounter: 3,
+        maxRender: 4,
+        maxCounter: 99,
+      };
+    },
+    computed: {
+      numberOverLimit() {
+        return this.issue.assignees.length - this.limitBeforeCounter;
+      },
+      assigneeCounterTooltip() {
+        return `${this.assigneeCounterLabel} more`;
+      },
+      assigneeCounterLabel() {
+        if (this.numberOverLimit > this.maxCounter) {
+          return `${this.maxCounter}+`;
+        }
+
+        return `+${this.numberOverLimit}`;
+      },
+      shouldRenderCounter() {
+        if (this.issue.assignees.length <= this.maxRender) {
+          return false;
+        }
+
+        return this.issue.assignees.length > this.numberOverLimit;
+      },
+      cardUrl() {
+        return `${this.issueLinkBase}/${this.issue.id}`;
+      },
+      issueId() {
+        return `#${this.issue.id}`;
+      },
+      showLabelFooter() {
+        return this.issue.labels.find(l => this.showLabel(l)) !== undefined;
+      },
+    },
     methods: {
+      isIndexLessThanlimit(index) {
+        return index < this.limitBeforeCounter;
+      },
+      shouldRenderAssignee(index) {
+        // Eg. maxRender is 4,
+        // Render up to all 4 assignees if there are only 4 assigness
+        // Otherwise render up to the limitBeforeCounter
+        if (this.issue.assignees.length <= this.maxRender) {
+          return index < this.maxRender;
+        }
+
+        return index < this.limitBeforeCounter;
+      },
+      assigneeUrl(assignee) {
+        return `${this.rootPath}${assignee.username}`;
+      },
+      assigneeUrlTitle(assignee) {
+        return `Assigned to ${assignee.name}`;
+      },
+      avatarUrlTitle(assignee) {
+        return `Avatar for ${assignee.name}`;
+      },
       showLabel(label) {
         if (!this.list) return true;
 
@@ -67,35 +128,55 @@ import eventHub from '../eventhub';
     },
     template: `
       <div>
-        <h4 class="card-title">
-          <i
-            class="fa fa-eye-slash confidential-icon"
-            v-if="issue.confidential"></i>
-          <a
-            :href="issueLinkBase + '/' + issue.id"
-            :title="issue.title">
-            {{ issue.title }}
-          </a>
-        </h4>
-        <div class="card-footer">
-          <span
-            class="card-number"
-            v-if="issue.id">
-            #{{ issue.id }}
-          </span>
-          <a
-            class="card-assignee has-tooltip"
-            :href="rootPath + issue.assignee.username"
-            :title="'Assigned to ' + issue.assignee.name"
-            v-if="issue.assignee"
-            data-container="body">
-            <img
-              class="avatar avatar-inline s20"
-              :src="issue.assignee.avatar"
-              width="20"
-              height="20"
-              :alt="'Avatar for ' + issue.assignee.name" />
-          </a>
+        <div class="card-header">
+          <h4 class="card-title">
+            <i
+              class="fa fa-eye-slash confidential-icon"
+              v-if="issue.confidential"
+              aria-hidden="true"
+            />
+            <a
+              class="js-no-trigger"
+              :href="cardUrl"
+              :title="issue.title">{{ issue.title }}</a>
+            <span
+              class="card-number"
+              v-if="issue.id"
+            >
+              {{ issueId }}
+            </span>
+          </h4>
+          <div class="card-assignee">
+            <a
+              class="has-tooltip js-no-trigger"
+              :href="assigneeUrl(assignee)"
+              :title="assigneeUrlTitle(assignee)"
+              v-for="(assignee, index) in issue.assignees"
+              v-if="shouldRenderAssignee(index)"
+              data-container="body"
+              data-placement="bottom"
+            >
+              <img
+                class="avatar avatar-inline s20"
+                :src="assignee.avatar"
+                width="20"
+                height="20"
+                :alt="avatarUrlTitle(assignee)"
+              />
+            </a>
+            <span
+              class="avatar-counter has-tooltip"
+              :title="assigneeCounterTooltip"
+              v-if="shouldRenderCounter"
+            >
+             {{ assigneeCounterLabel }}
+            </span>
+          </div>
+        </div>
+        <div
+          class="card-footer"
+          v-if="showLabelFooter"
+        >
           <button
             class="label color-label has-tooltip"
             v-for="label in issue.labels"

app/assets/javascripts/boards/models/issue.js

@@ -15,14 +15,9 @@ class ListIssue {
     this.subscribed = obj.subscribed;
     this.labels = [];
     this.selected = false;
-    this.assignee = false;
     this.position = obj.relative_position || Infinity;
     this.milestone_id = obj.milestone_id;
 
-    if (obj.assignee) {
-      this.assignee = new ListUser(obj.assignee);
-    }
-
     if (obj.milestone) {
       this.milestone = new ListMilestone(obj.milestone);
     }
@@ -30,6 +25,8 @@ class ListIssue {
     obj.labels.forEach((label) => {
       this.labels.push(new ListLabel(label));
     });
+
+    this.assignees = obj.assignees.map(a => new ListUser(a));
   }
 
   addLabel (label) {

app/assets/stylesheets/pages/boards.scss

@@ -226,7 +226,7 @@
 
 .card {
   position: relative;
-  padding: 10px $gl-padding;
+  padding: 11px 10px 11px $gl-padding;
   background: $white-light;
   border-radius: $border-radius-default;
   box-shadow: 0 1px 2px $issue-boards-card-shadow;
@@ -236,8 +236,13 @@
     margin-bottom: 5px;
   }
 
-  &.is-active {
+  &.is-active,
+  &.is-active .card-assignee:hover a {
     background-color: $row-hover;
+
+    &:first-child:not(:only-child) {
+      box-shadow: -10px 0 10px 1px $row-hover;
+    }
   }
 
   .label {
@@ -246,36 +251,111 @@
   }
 
   .confidential-icon {
+    position: relative;
+    top: 1px;
     margin-right: 5px;
   }
 }
 
 .card-title {
-  margin: 0;
+  margin: 0 30px 0 0;
   font-size: 1em;
+  line-height: inherit;
 
   a {
-    color: inherit;
+    color: $gl-text-color;
     word-wrap: break-word;
+    margin-right: 2px;
   }
 }
 
-.card-footer {
-  margin-top: 5px;
-  line-height: 25px;
+.card-header {
+  display: flex;
+  min-height: 20px;
 
-  .label {
-    margin-right: 5px;
-    font-size: (14px / $issue-boards-font-size) * 1em;
+  .card-assignee {
+    display: flex;
+    justify-content: flex-end;
+    position: absolute;
+    right: 15px;
+    height: 20px;
+    width: 20px;
+
+    .avatar-counter {
+      display: none;
+      vertical-align: middle;
+      min-width: 20px;
+      line-height: 19px;
+      height: 20px;
+      padding-left: 2px;
+      padding-right: 2px;
+      border-radius: 2em;
+    }
+
+    img {
+      vertical-align: top;
+    }
+
+    a {
+      position: relative;
+      margin-left: -15px;
+    }
+
+    a:nth-child(1) {
+      z-index: 3;
+    }
+
+    a:nth-child(2) {
+      z-index: 2;
+    }
+
+    a:nth-child(3) {
+      z-index: 1;
+    }
+
+    a:nth-child(4) {
+      display: none;
+    }
+
+    &:hover {
+      .avatar-counter {
+        display: inline-block;
+      }
+
+      a {
+        position: static;
+        background-color: $white-light;
+        transition: background-color 0s;
+        margin-left: auto;
+
+        &:nth-child(4) {
+          display: block;
+        }
+
+        &:first-child:not(:only-child) {
+          box-shadow: -10px 0 10px 1px $white-light;
+        }
+      }
+    }
   }
 
   .avatar {
-    margin-left: 0;
+    margin: 0;
+  }
+}
+
+.card-footer {
+  margin: 0 0 5px;
+
+  .label {
+    margin-top: 5px;
+    margin-right: 6px;
   }
 }
 
 .card-number {
-  margin-right: 5px;
+  font-size: 12px;
+  color: $gl-text-color-secondary;
 }
 
 .issue-boards-search {

app/finders/issuable_finder.rb

@@ -231,6 +231,17 @@ class IssuableFinder
     klass.all
   end
 
+  def by_scope(items)
+    case params[:scope]
+    when 'created-by-me', 'authored'
+      items.where(author_id: current_user.id)
+    when 'assigned-to-me'
+      items.assigned_to(current_user)
+    else
+      items
+    end
+  end
+
   def by_state(items)
     case params[:state].to_s
     when 'closed'

app/finders/issues_finder.rb

@@ -28,40 +28,26 @@ class IssuesFinder < IssuableFinder
 
   def by_assignee(items)
     if assignee
-      items = items.where("issue_assignees.user_id = ?", assignee.id)
+      items.assigned_to(assignee)
     elsif no_assignee?
-      items = items.where("issue_assignees.user_id is NULL")
+      items.unassigned
     elsif assignee_id? || assignee_username? # assignee not found
-      items = items.none
-    end
-
-    items
-  end
-
-  def by_scope(items)
-    case params[:scope]
-    when 'created-by-me', 'authored'
-      items.where(author_id: current_user.id)
-    when 'assigned-to-me'
-      items.where("issue_assignees.user_id = ?", current_user.id)
+      items.none
     else
       items
     end
   end
 
   def self.not_restricted_by_confidentiality(user)
-    issues = Issue.with_assignees
-
-    return issues.where('issues.confidential IS NULL OR issues.confidential IS FALSE') if user.blank?
+    return Issue.where('issues.confidential IS NOT TRUE') if user.blank?
 
-    return issues.all if user.admin_or_auditor?
+    return Issue.all if user.admin_or_auditor?
 
-    issues.where('
-      issues.confidential IS NULL
-      OR issues.confidential IS FALSE
+    Issue.where('
+      issues.confidential IS NOT TRUE
       OR (issues.confidential = TRUE
         AND (issues.author_id = :user_id
-          OR issue_assignees.user_id = :user_id
+          OR EXISTS (SELECT TRUE FROM issue_assignees WHERE user_id = :user_id AND issue_id = issues.id)
           OR issues.project_id IN(:project_ids)))',
       user_id: user.id,
       project_ids: user.authorized_projects(Gitlab::Access::REPORTER).select(:id))

app/finders/merge_requests_finder.rb

@@ -23,17 +23,6 @@ class MergeRequestsFinder < IssuableFinder
 
   private
 
-  def by_scope(items)
-    case params[:scope]
-    when 'created-by-me', 'authored'
-      items.where(author_id: current_user.id)
-    when 'assigned-to-me'
-      items.where(assignee_id: current_user.id)
-    else
-      items
-    end
-  end
-
   def item_project_ids(items)
     items&.reorder(nil)&.select(:target_project_id)
   end

app/models/concerns/milestoneish.rb

@@ -40,7 +40,7 @@ module Milestoneish
   def issues_visible_to_user(user)
     memoize_per_user(user, :issues_visible_to_user) do
       IssuesFinder.new(user, issues_finder_params)
-        .execute.where(milestone_id: milestoneish_ids)
+        .execute.includes(:assignees).where(milestone_id: milestoneish_ids)
     end
   end
 

app/models/global_milestone.rb

@@ -36,7 +36,7 @@ class GlobalMilestone
     closed = count_by_state(milestones_by_state_and_title, 'closed')
     all = milestones_by_state_and_title.map { |(_, title), _| title }.uniq.count
 
-    { 
+    {
       opened: opened,
       closed: closed,
       all: all
@@ -94,7 +94,7 @@ class GlobalMilestone
   end
 
   def participants
-    @participants ||= milestones.includes(:participants).map(&:participants).flatten.compact.uniq
+    @participants ||= milestones.map(&:participants).flatten.uniq
   end
 
   def labels

app/models/issue.rb

@@ -34,13 +34,11 @@ class Issue < ActiveRecord::Base
 
   validates :project, presence: true
 
-  scope :cared, ->(user) { with_assignees.where("issue_assignees.user_id IN(?)", user.id) }
   scope :open_for, ->(user) { opened.assigned_to(user) }
   scope :in_projects, ->(project_ids) { where(project_id: project_ids) }
-  scope :with_assignees, -> { joins("LEFT JOIN issue_assignees ON issue_id = issues.id") }
-  scope :assigned, -> { with_assignees.where('issue_assignees.user_id IS NOT NULL') }
-  scope :unassigned, -> { with_assignees.where('issue_assignees.user_id IS NULL') }
-  scope :assigned_to, ->(u) { with_assignees.where('issue_assignees.user_id = ?', u.id)}
+  scope :assigned, -> { where('EXISTS (SELECT TRUE FROM issue_assignees WHERE issue_id = issues.id)') }
+  scope :unassigned, -> { where('NOT EXISTS (SELECT TRUE FROM issue_assignees WHERE issue_id = issues.id)') }
+  scope :assigned_to, ->(u) { where('EXISTS (SELECT TRUE FROM issue_assignees WHERE user_id = ? AND issue_id = issues.id)', u.id)}
 
   scope :without_due_date, -> { where(due_date: nil) }
   scope :due_before, ->(date) { where('issues.due_date < ?', date) }

app/models/user.rb

@@ -106,7 +106,7 @@ class User < ActiveRecord::Base
   has_many :protected_branch_push_access_levels, dependent: :destroy, class_name: ProtectedBranch::PushAccessLevel
   has_many :triggers,                 dependent: :destroy, class_name: 'Ci::Trigger', foreign_key: :owner_id
 
-  has_many :issue_assignees, dependent: :destroy
+  has_many :issue_assignees
   has_many :assigned_issues, class_name: "Issue", through: :issue_assignees, source: :issue
   has_many :assigned_merge_requests,  dependent: :nullify, foreign_key: :assignee_id, class_name: "MergeRequest"
 

app/services/issues/base_service.rb

@@ -22,9 +22,9 @@ module Issues
     end
 
     def filter_assignee(issuable)
-      return if params[:assignee_ids].to_a.empty?
+      return if params[:assignee_ids].blank?
 
-      assignee_ids = params[:assignee_ids].select{ |assignee_id| assignee_can_read?(issuable, assignee_id)}
+      assignee_ids = params[:assignee_ids].select { |assignee_id| assignee_can_read?(issuable, assignee_id) }
 
       if params[:assignee_ids].map(&:to_s) == [IssuableFinder::NONE]
         params[:assignee_ids] = []

app/services/issues/export_csv_service.rb

@@ -21,7 +21,7 @@ module Issues
 
     def csv_builder
       @csv_builder ||=
-        CsvBuilder.new(@issues.includes(:author), header_to_value_hash)
+        CsvBuilder.new(@issues.includes(:author, :assignees), header_to_value_hash)
     end
 
     private
@@ -35,8 +35,8 @@ module Issues
        'Description' => 'description',
        'Author' => 'author_name',
        'Author Username' => -> (issue) { issue.author&.username },
-       'Assignee' => -> (issue) { issue.assignees.pluck(:name).join(', ') },
-       'Assignee Username' => -> (issue) { issue.assignees.pluck(:username).join(', ') },
+       'Assignee' => -> (issue) { issue.assignees.map(&:name).join(', ') },
+       'Assignee Username' => -> (issue) { issue.assignees.map(&:username).join(', ') },
        'Confidential' => -> (issue) { issue.confidential? ? 'Yes' : 'No' },
        'Due Date' => -> (issue) { issue.due_date&.to_s(:csv) },
        'Created At (UTC)' => -> (issue) { issue.created_at&.to_s(:csv) },

app/services/issues/update_service.rb

@@ -22,7 +22,7 @@ module Issues
       end
 
       if issue.previous_changes.include?('title') ||
-        issue.previous_changes.include?('description')
+          issue.previous_changes.include?('description')
         todo_service.update_issue(issue, current_user)
       end
 

app/services/merge_requests/assign_issues_service.rb

@@ -4,7 +4,7 @@ module MergeRequests
       @assignable_issues ||= begin
         if current_user == merge_request.author
           closes_issues.select do |issue|
-            !issue.is_a?(ExternalIssue) && !issue.assignees.any? && can?(current_user, :admin_issue, issue)
+            !issue.is_a?(ExternalIssue) && !issue.assignees.present? && can?(current_user, :admin_issue, issue)
           end
         else
           []

app/services/notification_recipient_service.rb

@@ -29,7 +29,7 @@ class NotificationRecipientService
       recipients << target.assignee
     when :reassign_issue
       previous_assignees = Array(previous_assignee)
-      recipients.concat(previous_assignees) if previous_assignees.any?
+      recipients.concat(previous_assignees)
       recipients.concat(target.assignees)
     end
 

app/services/slash_commands/interpret_service.rb

@@ -86,15 +86,18 @@ module SlashCommands
       current_user.can?(:"admin_#{issuable.to_ability_name}", project)
     end
     command :assign do |assignee_param|
-      user = extract_references(assignee_param, :user).first
-      user ||= User.find_by(username: assignee_param)
+      user_ids = extract_references(assignee_param, :user).map(&:id)
 
-      next unless user
+      if user_ids.empty?
+        user_ids = User.where(username: assignee_param.split(' ').map(&:strip)).pluck(:id)
+      end
+
+      next if user_ids.empty?
 
       if issuable.is_a?(Issue)
-        @updates[:assignee_ids] = [user.id]
+        @updates[:assignee_ids] = user_ids
       else
-        @updates[:assignee_id] = user.id
+        @updates[:assignee_id] = user_ids.last
       end
     end
 

app/services/system_note_service.rb

@@ -54,7 +54,7 @@ module SystemNoteService
   # issue - Issue object
   # project  - Project owning noteable
   # author   - User performing the change
-  # assignees - User being assigned, or nil
+  # assignees - Users being assigned, or nil
   #
   # Example Note text:
   #

app/views/notify/_reassigned_issuable_email.text.erb

-Reassigned Issue <%= @issue.iid %>
-
-<%= url_for([@issue.project.namespace.becomes(Namespace), @issue.project, @issue, { only_path: false }]) %>
-
-Assignee changed <%= "from #{@previous_assignees.map(&:name).to_sentence}" if @previous_assignees.any? -%>
- to <%= "#{@issue.assignees.any? ? @issue.assignee_list : 'Unassigned'}" %>

app/views/notify/new_mention_in_issue_email.html.haml

@@ -7,6 +7,6 @@
 - if @issue.description
   = markdown(@issue.description, pipeline: :email, author: @issue.author)
 
-- if @issue.assignees.any?
+- if @issue.assignees.present?
   %p
     Assignee: #{@issue.assignee_list}

app/views/notify/reassigned_issue_email.html.haml

@@ -8,4 +8,3 @@
     %strong= @issue.assignee_list
   - else
     %strong Unassigned
-

app/views/notify/reassigned_issue_email.text.erb

-<%= render 'reassigned_issuable_email', issuable: @issue %>
+Reassigned Issue <%= @issue.iid %>
+
+<%= url_for([@issue.project.namespace.becomes(Namespace), @issue.project, @issue, { only_path: false }]) %>
+
+Assignee changed <%= "from #{@previous_assignees.map(&:name).to_sentence}" if @previous_assignees.any? -%>
+ to <%= "#{@issue.assignees.any? ? @issue.assignee_list : 'Unassigned'}" %>

app/views/notify/reassigned_merge_request_email.html.haml

-= render 'reassigned_issuable_email', issuable: @merge_request
+Reassigned Merge Request #{ @merge_request.iid }
+
+= url_for([@merge_request.project.namespace.becomes(Namespace), @merge_request.project, @merge_request, { only_path: false }])
+
+Assignee changed
+- if @previous_assignee
+  from #{@previous_assignee.name}
+to
+= @merge_request.assignee_id ? @merge_request.assignee_name : 'Unassigned'

changelogs/unreleased/update-issue-board-cards-design.yml

+---
+title: Update issue board cards design
+merge_request: 10353
+author:

db/migrate/20170320171632_create_issue_assignees_table.rb

@@ -26,7 +26,7 @@ class CreateIssueAssigneesTable < ActiveRecord::Migration
   # disable_ddl_transaction!
 
   def up
-    create_table :issue_assignees do |t|
+    create_table :issue_assignees, id: false do |t|
       t.references :user, foreign_key: { on_delete: :cascade }, index: true, null: false
       t.references :issue, foreign_key: { on_delete: :cascade }, null: false
     end
@@ -35,10 +35,6 @@ class CreateIssueAssigneesTable < ActiveRecord::Migration
   end
 
   def down
-    if index_exists?(:issue_assignees, name: INDEX_NAME)
-      remove_index :issue_assignees, name: INDEX_NAME
-    end
-
     drop_table :issue_assignees
   end
 end

db/migrate/20170320173259_migrate_assignees.rb

@@ -21,9 +21,23 @@ class MigrateAssignees < ActiveRecord::Migration
   #
   # To disable transactions uncomment the following line and remove these
   # comments:
-  # disable_ddl_transaction!
+  disable_ddl_transaction!
 
   def up
+    # Optimisation: this accounts for most of the invalid assignee IDs on GitLab.com
+    update_column_in_batches(:issues, :assignee_id, nil) do |table, query|
+      query.where(table[:assignee_id].eq(0))
+    end
+
+    users = Arel::Table.new(:users)
+
+    update_column_in_batches(:issues, :assignee_id, nil) do |table, query|
+      query.where(table[:assignee_id].not_eq(nil)\
+        .and(
+          users.project("true").where(users[:id].eq(table[:assignee_id])).exists.not
+        ))
+    end
+
     execute <<-EOF
       INSERT INTO issue_assignees(issue_id, user_id)
       SELECT id, assignee_id FROM issues WHERE assignee_id IS NOT NULL

db/schema.rb

@@ -495,7 +495,7 @@ ActiveRecord::Schema.define(version: 20170320173259) do
 
   add_index "index_statuses", ["project_id"], name: "index_index_statuses_on_project_id", unique: true, using: :btree
 
-  create_table "issue_assignees", force: :cascade do |t|
+  create_table "issue_assignees", id: false, force: :cascade do |t|
     t.integer "user_id", null: false
     t.integer "issue_id", null: false
   end

doc/api/issues.md

@@ -68,14 +68,14 @@ Example response:
          "updated_at" : "2016-01-04T15:31:39.996Z"
       },
       "project_id" : 1,
-      "assignee" : {
+      "assignees" : [{
          "state" : "active",
          "id" : 1,
          "name" : "Administrator",
          "web_url" : "https://gitlab.example.com/root",
          "avatar_url" : null,
          "username" : "root"
-      },
+      }],
       "updated_at" : "2016-01-04T15:31:51.081Z",
       "id" : 76,
       "title" : "Consequatur vero maxime deserunt laboriosam est voluptas dolorem.",
@@ -150,14 +150,14 @@ Example response:
       "description" : "Omnis vero earum sunt corporis dolor et placeat.",
       "state" : "closed",
       "iid" : 1,
-      "assignee" : {
+      "assignees" : [{
          "avatar_url" : null,
          "web_url" : "https://gitlab.example.com/lennie",
          "state" : "active",
          "username" : "lennie",
          "id" : 9,
          "name" : "Dr. Luella Kovacek"
-      },
+      }],
       "labels" : [],
       "id" : 41,
       "title" : "Ut commodi ullam eos dolores perferendis nihil sunt.",
@@ -231,14 +231,14 @@ Example response:
       "description" : "Omnis vero earum sunt corporis dolor et placeat.",
       "state" : "closed",
       "iid" : 1,
-      "assignee" : {
+      "assignees" : [{
          "avatar_url" : null,
          "web_url" : "https://gitlab.example.com/lennie",
          "state" : "active",
          "username" : "lennie",
          "id" : 9,
          "name" : "Dr. Luella Kovacek"
-      },
+      }],
       "labels" : [],
       "id" : 41,
       "title" : "Ut commodi ullam eos dolores perferendis nihil sunt.",
@@ -297,14 +297,14 @@ Example response:
    "description" : "Omnis vero earum sunt corporis dolor et placeat.",
    "state" : "closed",
    "iid" : 1,
-   "assignee" : {
+   "assignees" : [{
       "avatar_url" : null,
       "web_url" : "https://gitlab.example.com/lennie",
       "state" : "active",
       "username" : "lennie",
       "id" : 9,
       "name" : "Dr. Luella Kovacek"
-   },
+   }],
    "labels" : [],
    "id" : 41,
    "title" : "Ut commodi ullam eos dolores perferendis nihil sunt.",
@@ -333,7 +333,7 @@ POST /projects/:id/issues
 | `title`                                   | string  | yes      | The title of an issue                                                                                                                                                                                                                                |
 | `description`                             | string  | no       | The description of an issue                                                                                                                                                                                                                          |
 | `confidential`                            | boolean | no       | Set an issue to be confidential. Default is `false`.                                                                                                                                                                                                 |
-| `assignee_id`                             | integer | no       | The ID of a user to assign issue                                                                                                                                                                                                                     |
+| `assignee_ids`                             | Array[integer] | no       | The ID of a user to assign issue                                                                                                                                                                                                                     |
 | `milestone_id`                            | integer | no       | The ID of a milestone to assign issue                                                                                                                                                                                                                |
 | `labels`                                  | string  | no       | Comma-separated label names for an issue                                                                                                                                                                                                             |
 | `created_at`                              | string  | no       | Date time string, ISO 8601 formatted, e.g. `2016-03-11T03:45:40Z` (requires admin or project owner rights)                                                                                                                                           |
@@ -356,7 +356,7 @@ Example response:
    "iid" : 14,
    "title" : "Issues with auth",
    "state" : "opened",
-   "assignee" : null,
+   "assignees" : [],
    "labels" : [
       "bug"
    ],
@@ -396,7 +396,7 @@ PUT /projects/:id/issues/:issue_iid
 | `title`        | string  | no       | The title of an issue                                                                                      |
 | `description`  | string  | no       | The description of an issue                                                                                |
 | `confidential` | boolean | no       | Updates an issue to be confidential                                                                        |
-| `assignee_id`  | integer | no       | The ID of a user to assign the issue to                                                                    |
+| `assignee_ids`  | Array[integer] | no       | The ID of a user to assign the issue to                                                                    |
 | `milestone_id` | integer | no       | The ID of a milestone to assign the issue to                                                               |
 | `labels`       | string  | no       | Comma-separated label names for an issue                                                                   |
 | `state_event`  | string  | no       | The state event of an issue. Set `close` to close the issue and `reopen` to reopen it                      |
@@ -431,7 +431,7 @@ Example response:
       "bug"
    ],
    "id" : 85,
-   "assignee" : null,
+   "assignees" : [],
    "milestone" : null,
    "subscribed" : true,
    "user_notes_count": 0,
@@ -496,14 +496,14 @@ Example response:
   "updated_at": "2016-04-07T12:20:17.596Z",
   "labels": [],
   "milestone": null,
-  "assignee": {
+  "assignees": [{
     "name": "Miss Monserrate Beier",
     "username": "axel.block",
     "id": 12,
     "state": "active",
     "avatar_url": "http://www.gravatar.com/avatar/46f6f7dc858ada7be1853f7fb96e81da?s=80&d=identicon",
     "web_url": "https://gitlab.example.com/axel.block"
-  },
+  }],
   "author": {
     "name": "Kris Steuber",
     "username": "solon.cremin",
@@ -552,14 +552,14 @@ Example response:
   "updated_at": "2016-04-07T12:20:17.596Z",
   "labels": [],
   "milestone": null,
-  "assignee": {
+  "assignees": [{
     "name": "Miss Monserrate Beier",
     "username": "axel.block",
     "id": 12,
     "state": "active",
     "avatar_url": "http://www.gravatar.com/avatar/46f6f7dc858ada7be1853f7fb96e81da?s=80&d=identicon",
     "web_url": "https://gitlab.example.com/axel.block"
-  },
+  }],
   "author": {
     "name": "Kris Steuber",
     "username": "solon.cremin",
@@ -656,14 +656,14 @@ Example response:
       "updated_at": "2016-06-17T07:47:33.832Z",
       "due_date": null
     },
-    "assignee": {
+    "assignees": [{
       "name": "Jarret O'Keefe",
       "username": "francisca",
       "id": 14,
       "state": "active",
       "avatar_url": "http://www.gravatar.com/avatar/a7fa515d53450023c83d62986d0658a8?s=80&d=identicon",
       "web_url": "https://gitlab.example.com/francisca"
-    },
+    }],
     "author": {
       "name": "Maxie Medhurst",
       "username": "craig_rutherford",

doc/user/project/integrations/webhooks.md

@@ -232,7 +232,7 @@ X-Gitlab-Event: Issue Hook
   "object_attributes": {
     "id": 301,
     "title": "New API: create/update/delete file",
-    "assignee_id": 51,
+    "assignee_ids": [51],
     "author_id": 51,
     "project_id": 14,
     "created_at": "2013-12-03T17:15:43Z",
@@ -246,11 +246,11 @@ X-Gitlab-Event: Issue Hook
     "url": "http://example.com/diaspora/issues/23",
     "action": "open"
   },
-  "assignee": {
+  "assignees": [{
     "name": "User1",
     "username": "user1",
     "avatar_url": "http://www.gravatar.com/avatar/e64c7d89f26bd1972efa854d13d7dd61?s=40\u0026d=identicon"
-  },
+  }],
   "labels": [{
     "id": 206,
     "title": "API",
@@ -544,7 +544,7 @@ X-Gitlab-Event: Note Hook
   "issue": {
     "id": 92,
     "title": "test",
-    "assignee_id": null,
+    "assignee_ids": [],
     "author_id": 1,
     "project_id": 5,
     "created_at": "2015-04-12 14:53:17 UTC",

lib/api/v3/entities.rb

@@ -295,6 +295,13 @@ module API
         expose :project_id, :issues_events, :merge_requests_events
         expose :note_events, :build_events, :pipeline_events, :wiki_page_events
       end
+
+      class Issue < ::API::Entities::Issue
+        unexpose :assignees
+        expose :assignee do |issue, options|
+          ::API::Entities::UserBasic.represent(issue.assignees.first, options)
+        end
+      end
     end
   end
 end

lib/api/v3/helpers.rb

@@ -14,6 +14,14 @@ module API
         authorize! access_level, merge_request
         merge_request
       end
+
+      def convert_parameters_from_legacy_format(params)
+        if params[:assignee_id].present?
+          params[:assignee_ids] = [params.delete(:assignee_id)]
+        end
+
+        params
+      end
     end
   end
 end

lib/api/v3/issues.rb

@@ -8,6 +8,7 @@ module API
       helpers do
         def find_issues(args = {})
           args = params.merge(args)
+          args = convert_parameters_from_legacy_format(args)
 
           args.delete(:id)
           args[:milestone_title] = args.delete(:milestone)
@@ -53,7 +54,7 @@ module API
 
       resource :issues do
         desc "Get currently authenticated user's issues" do
-          success ::API::Entities::Issue
+          success ::API::V3::Entities::Issue
         end
         params do
           optional :state, type: String, values: %w[opened closed all], default: 'all',
@@ -62,7 +63,7 @@ module API
         end
         get do
           issues = find_issues(scope: 'authored')
-          present paginate(issues), with: ::API::Entities::Issue, current_user: current_user
+          present paginate(issues), with: ::API::V3::Entities::Issue, current_user: current_user
         end
       end
 
@@ -71,7 +72,7 @@ module API
       end
       resource :groups, requirements: { id: %r{[^/]+} } do
         desc 'Get a list of group issues' do
-          success ::API::Entities::Issue
+          success ::API::V3::Entities::Issue
         end
         params do
           optional :state, type: String, values: %w[opened closed all], default: 'opened',
@@ -83,7 +84,7 @@ module API
 
           issues = find_issues(group_id: group.id, state: params[:state] || 'opened', match_all_labels: true)
 
-          present paginate(issues), with: ::API::Entities::Issue, current_user: current_user
+          present paginate(issues), with: ::API::V3::Entities::Issue, current_user: current_user
         end
       end
 
@@ -95,7 +96,7 @@ module API
 
         desc 'Get a list of project issues' do
           detail 'iid filter is deprecated have been removed on V4'
-          success ::API::Entities::Issue
+          success ::API::V3::Entities::Issue
         end
         params do
           optional :state, type: String, values: %w[opened closed all], default: 'all',
@@ -108,22 +109,22 @@ module API
 
           issues = find_issues(project_id: project.id)
 
-          present paginate(issues), with: ::API::Entities::Issue, current_user: current_user, project: user_project
+          present paginate(issues), with: ::API::V3::Entities::Issue, current_user: current_user, project: user_project
         end
 
         desc 'Get a single project issue' do
-          success ::API::Entities::Issue
+          success ::API::V3::Entities::Issue
         end
         params do
           requires :issue_id, type: Integer, desc: 'The ID of a project issue'
         end
         get ":id/issues/:issue_id" do
           issue = find_project_issue(params[:issue_id])
-          present issue, with: ::API::Entities::Issue, current_user: current_user, project: user_project
+          present issue, with: ::API::V3::Entities::Issue, current_user: current_user, project: user_project
         end
 
         desc 'Create a new project issue' do
-          success ::API::Entities::Issue
+          success ::API::V3::Entities::Issue
         end
         params do
           requires :title, type: String, desc: 'The title of an issue'
@@ -141,6 +142,7 @@ module API
 
           issue_params = declared_params(include_missing: false)
           issue_params = issue_params.merge(merge_request_to_resolve_discussions_of: issue_params.delete(:merge_request_for_resolving_discussions))
+          issue_params = convert_parameters_from_legacy_format(issue_params)
 
           issue = ::Issues::CreateService.new(user_project,
                                               current_user,
@@ -148,14 +150,14 @@ module API
           render_spam_error! if issue.spam?
 
           if issue.valid?
-            present issue, with: ::API::Entities::Issue, current_user: current_user, project: user_project
+            present issue, with: ::API::V3::Entities::Issue, current_user: current_user, project: user_project
           else
             render_validation_error!(issue)
           end
         end
 
         desc 'Update an existing issue' do
-          success ::API::Entities::Issue
+          success ::API::V3::Entities::Issue
         end
         params do
           requires :issue_id, type: Integer, desc: 'The ID of a project issue'
@@ -178,6 +180,7 @@ module API
           end
 
           update_params = declared_params(include_missing: false).merge(request: request, api: true)
+          update_params = convert_parameters_from_legacy_format(update_params)
 
           issue = ::Issues::UpdateService.new(user_project,
                                               current_user,
@@ -186,14 +189,14 @@ module API
           render_spam_error! if issue.spam?
 
           if issue.valid?
-            present issue, with: ::API::Entities::Issue, current_user: current_user, project: user_project
+            present issue, with: ::API::V3::Entities::Issue, current_user: current_user, project: user_project
           else
             render_validation_error!(issue)
           end
         end
 
         desc 'Move an existing issue' do
-          success ::API::Entities::Issue
+          success ::API::V3::Entities::Issue
         end
         params do
           requires :issue_id, type: Integer, desc: 'The ID of a project issue'
@@ -208,7 +211,7 @@ module API
 
           begin
             issue = ::Issues::MoveService.new(user_project, current_user).execute(issue, new_project)
-            present issue, with: ::API::Entities::Issue, current_user: current_user, project: user_project
+            present issue, with: ::API::V3::Entities::Issue, current_user: current_user, project: user_project
           rescue ::Issues::MoveService::MoveError => error
             render_api_error!(error.message, 400)
           end

lib/api/v3/merge_requests.rb

@@ -32,7 +32,7 @@ module API
             if project.has_external_issue_tracker?
               ::API::Entities::ExternalIssue
             else
-              ::API::Entities::Issue
+              ::API::V3::Entities::Issue
             end
           end
 

lib/api/v3/milestones.rb

@@ -39,7 +39,7 @@ module API
         end
 
         desc 'Get all issues for a single project milestone' do
-          success ::API::Entities::Issue
+          success ::API::V3::Entities::Issue
         end
         params do
           requires :milestone_id, type: Integer, desc: 'The ID of a project milestone'
@@ -56,7 +56,7 @@ module API
           }
 
           issues = IssuesFinder.new(current_user, finder_params).execute
-          present paginate(issues), with: ::API::Entities::Issue, current_user: current_user, project: user_project
+          present paginate(issues), with: ::API::V3::Entities::Issue, current_user: current_user, project: user_project
         end
       end
     end

spec/controllers/projects/merge_requests_controller_spec.rb

@@ -1329,7 +1329,7 @@ describe Projects::MergeRequestsController do
     end
 
     it 'correctly pluralizes flash message on success' do
-      issue2.update!(assignees: [user])
+      issue2.assignees = [user]
 
       post_assign_issues
 

spec/features/atom/dashboard_issues_spec.rb

@@ -41,7 +41,7 @@ describe "Dashboard Issues Feed", feature: true  do
 
           expect(entry).to be_present
           expect(entry).to have_selector('author email', text: issue2.author_public_email)
-          expect(entry).to have_selector('assignees email', text: issue2.assignees.first.public_email)
+          expect(entry).to have_selector('assignees email', text: assignee.public_email)
           expect(entry).not_to have_selector('labels')
           expect(entry).not_to have_selector('milestone')
           expect(entry).to have_selector('description', text: issue2.description)
@@ -64,7 +64,7 @@ describe "Dashboard Issues Feed", feature: true  do
 
           expect(entry).to be_present
           expect(entry).to have_selector('author email', text: issue1.author_public_email)
-          expect(entry).to have_selector('assignees email', text: issue1.assignees.first.public_email)
+          expect(entry).to have_selector('assignees email', text: assignee.public_email)
           expect(entry).to have_selector('labels label', text: label1.title)
           expect(entry).to have_selector('milestone', text: milestone1.title)
           expect(entry).not_to have_selector('description')

spec/features/atom/issues_spec.rb

@@ -22,7 +22,7 @@ describe 'Issues Feed', feature: true  do
           to have_content('application/atom+xml')
         expect(body).to have_selector('title', text: "#{project.name} issues")
         expect(body).to have_selector('author email', text: issue.author_public_email)
-        expect(body).to have_selector('assignee email', text: issue.author_public_email)
+        expect(body).to have_selector('assignees email', text: issue.author_public_email)
         expect(body).to have_selector('entry summary', text: issue.title)
       end
     end
@@ -36,7 +36,7 @@ describe 'Issues Feed', feature: true  do
           to have_content('application/atom+xml')
         expect(body).to have_selector('title', text: "#{project.name} issues")
         expect(body).to have_selector('author email', text: issue.author_public_email)
-        expect(body).to have_selector('assignee email', text: issue.author_public_email)
+        expect(body).to have_selector('assignees email', text: issue.author_public_email)
         expect(body).to have_selector('entry summary', text: issue.title)
       end
     end

spec/features/boards/add_issues_modal_spec.rb

@@ -131,7 +131,7 @@ describe 'Issue Boards add issue modal', :feature, :js do
     context 'selecing issues' do
       it 'selects single issue' do
         page.within('.add-issues-modal') do
-          first('.card').click
+          first('.card .card-number').click
 
           page.within('.nav-links') do
             expect(page).to have_content('Selected issues 1')
@@ -141,7 +141,7 @@ describe 'Issue Boards add issue modal', :feature, :js do
 
       it 'changes button text' do
         page.within('.add-issues-modal') do
-          first('.card').click
+          first('.card .card-number').click
 
           expect(first('.add-issues-footer .btn')).to have_content('Add 1 issue')
         end
@@ -149,7 +149,7 @@ describe 'Issue Boards add issue modal', :feature, :js do
 
       it 'changes button text with plural' do
         page.within('.add-issues-modal') do
-          all('.card').each do |el|
+          all('.card .card-number').each do |el|
             el.click
           end
 
@@ -159,7 +159,7 @@ describe 'Issue Boards add issue modal', :feature, :js do
 
       it 'shows only selected issues on selected tab' do
         page.within('.add-issues-modal') do
-          first('.card').click
+          first('.card .card-number').click
 
           click_link 'Selected issues'
 
@@ -189,7 +189,7 @@ describe 'Issue Boards add issue modal', :feature, :js do
 
       it 'selects all that arent already selected' do
         page.within('.add-issues-modal') do
-          first('.card').click
+          first('.card .card-number').click
 
           expect(page).to have_selector('.is-active', count: 1)
 
@@ -201,11 +201,11 @@ describe 'Issue Boards add issue modal', :feature, :js do
 
       it 'unselects from selected tab' do
         page.within('.add-issues-modal') do
-          first('.card').click
+          first('.card .card-number').click
 
           click_link 'Selected issues'
 
-          first('.card').click
+          first('.card .card-number').click
 
           expect(page).not_to have_selector('.is-active')
         end
@@ -215,7 +215,7 @@ describe 'Issue Boards add issue modal', :feature, :js do
     context 'adding issues' do
       it 'adds to board' do
         page.within('.add-issues-modal') do
-          first('.card').click
+          first('.card .card-number').click
 
           click_button 'Add 1 issue'
         end
@@ -227,7 +227,7 @@ describe 'Issue Boards add issue modal', :feature, :js do
 
       it 'adds to second list' do
         page.within('.add-issues-modal') do
-          first('.card').click
+          first('.card .card-number').click
 
           click_button planning.title
 

spec/features/issues/csv_spec.rb

@@ -80,6 +80,6 @@ describe 'Issues csv', feature: true do
                 author: user,
                 milestone: milestone,
                 labels: [feature_label, idea_label])
-    expect{ request_csv }.not_to exceed_query_limit(control_count + 23)
+    expect{ request_csv }.not_to exceed_query_limit(control_count + 5)
   end
 end

spec/features/unsubscribe_links_spec.rb

@@ -6,7 +6,7 @@ describe 'Unsubscribe links', feature: true do
   let(:recipient) { create(:user) }
   let(:author) { create(:user) }
   let(:project) { create(:empty_project, :public) }
-  let(:params) { { title: 'A bug!', description: 'Fix it!', assignee: recipient } }
+  let(:params) { { title: 'A bug!', description: 'Fix it!', assignees: [recipient] } }
   let(:issue) { Issues::CreateService.new(project, author, params).execute }
 
   let(:mail) { ActionMailer::Base.deliveries.last }

spec/models/concerns/elastic/issue_spec.rb

@@ -31,13 +31,14 @@ describe Issue, elastic: true do
   end
 
   it "returns json with all needed elements" do
-    issue = create :issue, project: project
+    assignee = create(:user)
+    issue = create :issue, project: project, assignees: [assignee]
 
     expected_hash = issue.attributes.extract!('id', 'iid', 'title', 'description', 'created_at',
                                                 'updated_at', 'state', 'project_id', 'author_id',
                                                 'confidential')
 
-    expected_hash['assignee_id'] = []
+    expected_hash['assignee_id'] = [assignee.id]
 
     expect(issue.as_indexed_json).to eq(expected_hash)
   end

spec/models/concerns/issuable_spec.rb

@@ -56,84 +56,6 @@ describe Issue, "Issuable" do
     end
   end
 
-  describe "before_save" do
-    describe "#update_cache_counts when an issue is reassigned" do
-      context "when previous assignee exists" do
-        before do
-          assignee = create(:user)
-          issue.project.team << [assignee, :developer]
-          issue.assignees << assignee
-        end
-
-        it "updates cache counts for new assignee" do
-          user = create(:user)
-
-          expect(user).to receive(:update_cache_counts)
-
-          issue.assignees << user
-        end
-
-        it "updates cache counts for previous assignee" do
-          old_assignee = issue.assignees.first
-
-          expect_any_instance_of(User).to receive(:update_cache_counts)
-
-          issue.assignees.destroy_all
-        end
-      end
-
-      context "when previous assignee does not exist" do
-        before{ issue.assignees = [] }
-
-        it "updates cache count for the new assignee" do
-          expect_any_instance_of(User).to receive(:update_cache_counts)
-
-          issue.assignees << user
-        end
-      end
-    end
-
-    describe "#update_cache_counts when a merge request is reassigned" do
-      let(:project) { create :project }
-      let(:merge_request) { create(:merge_request, source_project: project, target_project: project) }
-
-      context "when previous assignee exists" do
-        before do
-          assignee = create(:user)
-          project.team << [assignee, :developer]
-          merge_request.update(assignee: assignee)
-        end
-
-        it "updates cache counts for new assignee" do
-          user = create(:user)
-
-          expect(user).to receive(:update_cache_counts)
-
-          merge_request.update(assignee: user)
-        end
-
-        it "updates cache counts for previous assignee" do
-          old_assignee = merge_request.assignee
-          allow(User).to receive(:find_by_id).with(old_assignee.id).and_return(old_assignee)
-
-          expect(old_assignee).to receive(:update_cache_counts)
-
-          merge_request.update(assignee: nil)
-        end
-      end
-
-      context "when previous assignee does not exist" do
-        before { merge_request.update(assignee: nil) }
-
-        it "updates cache count for the new assignee" do
-          expect_any_instance_of(User).to receive(:update_cache_counts)
-
-          merge_request.update(assignee: user)
-        end
-      end
-    end
-  end
-
   describe ".search" do
     let!(:searchable_issue) { create(:issue, title: "Searchable issue") }
 

spec/models/issue_spec.rb

@@ -38,6 +38,46 @@ describe Issue, models: true do
     end
   end
 
+  describe "before_save" do
+    describe "#update_cache_counts when an issue is reassigned" do
+      let(:issue) { create(:issue) }
+      let(:assignee) { create(:user) }
+
+      context "when previous assignee exists" do
+        before do
+          issue.project.team << [assignee, :developer]
+          issue.assignees << assignee
+        end
+
+        it "updates cache counts for new assignee" do
+          user = create(:user)
+
+          expect(user).to receive(:update_cache_counts)
+
+          issue.assignees << user
+        end
+
+        it "updates cache counts for previous assignee" do
+          issue.assignees.first
+
+          expect_any_instance_of(User).to receive(:update_cache_counts)
+
+          issue.assignees.destroy_all
+        end
+      end
+
+      context "when previous assignee does not exist" do
+        it "updates cache count for the new assignee" do
+          issue.assignees = []
+
+          expect_any_instance_of(User).to receive(:update_cache_counts)
+
+          issue.assignees << assignee
+        end
+      end
+    end
+  end
+
   describe '#card_attributes' do
     it 'includes the author name' do
       allow(subject).to receive(:author).and_return(double(name: 'Robert'))

spec/models/merge_request_spec.rb

@@ -88,6 +88,48 @@ describe MergeRequest, models: true do
     end
   end
 
+  describe "before_save" do
+    describe "#update_cache_counts when a merge request is reassigned" do
+      let(:project) { create :project }
+      let(:merge_request) { create(:merge_request, source_project: project, target_project: project) }
+      let(:assignee) { create :user }
+
+      context "when previous assignee exists" do
+        before do
+          project.team << [assignee, :developer]
+          merge_request.update(assignee: assignee)
+        end
+
+        it "updates cache counts for new assignee" do
+          user = create(:user)
+
+          expect(user).to receive(:update_cache_counts)
+
+          merge_request.update(assignee: user)
+        end
+
+        it "updates cache counts for previous assignee" do
+          old_assignee = merge_request.assignee
+          allow(User).to receive(:find_by_id).with(old_assignee.id).and_return(old_assignee)
+
+          expect(old_assignee).to receive(:update_cache_counts)
+
+          merge_request.update(assignee: nil)
+        end
+      end
+
+      context "when previous assignee does not exist" do
+        it "updates cache count for the new assignee" do
+          merge_request.update(assignee: nil)
+
+          expect_any_instance_of(User).to receive(:update_cache_counts)
+
+          merge_request.update(assignee: assignee)
+        end
+      end
+    end
+  end
+
   describe '#card_attributes' do
     it 'includes the author name' do
       allow(subject).to receive(:author).and_return(double(name: 'Robert'))

spec/services/merge_requests/assign_issues_service_spec.rb

@@ -15,14 +15,14 @@ describe MergeRequests::AssignIssuesService, services: true do
     expect(service.assignable_issues.map(&:id)).to include(issue.id)
   end
 
-  it 'ignores issues already assigned to any user' do
-    issue.assignees = [create(:user)]
+  it 'ignores issues the user cannot update assignee on' do
+    project.team.truncate
 
     expect(service.assignable_issues).to be_empty
   end
 
-  it 'ignores issues the user cannot update assignee on' do
-    project.team.truncate
+  it 'ignores issues already assigned to any user' do
+    issue.assignees = [create(:user)]
 
     expect(service.assignable_issues).to be_empty
   end

spec/services/notification_service_spec.rb

@@ -460,7 +460,7 @@ describe NotificationService, services: true do
       it do
         notification.new_issue(issue, @u_disabled)
 
-        should_email(issue.assignees.first)
+        should_email(assignee)
         should_email(@u_watcher)
         should_email(@u_guest_watcher)
         should_email(@u_guest_custom)

spec/services/slash_commands/interpret_service_spec.rb

@@ -3,6 +3,7 @@ require 'spec_helper'
 describe SlashCommands::InterpretService, services: true do
   let(:project) { create(:project, :public) }
   let(:developer) { create(:user) }
+  let(:developer2) { create(:user) }
   let(:issue) { create(:issue, project: project) }
   let(:milestone) { create(:milestone, project: project, title: '9.10') }
   let(:inprogress) { create(:label, project: project, title: 'In Progress') }
@@ -388,6 +389,28 @@ describe SlashCommands::InterpretService, services: true do
       end
     end
 
+    context 'assign command with multiple assignees' do
+      let(:content) { "/assign @#{developer.username} @#{developer2.username}" }
+
+      before{ project.team << [developer2, :developer] }
+
+      context 'Issue' do
+        it 'fetches assignee and populates assignee_id if content contains /assign' do
+          _, updates = service.execute(content, issue)
+
+          expect(updates[:assignee_ids]).to match_array([developer.id, developer2.id])
+        end
+      end
+
+      context 'Merge Request' do
+        it 'fetches assignee and populates assignee_id if content contains /assign' do
+          _, updates = service.execute(content, merge_request)
+
+          expect(updates).to eq(assignee_id: developer.id)
+        end
+      end
+    end
+
     it_behaves_like 'empty command' do
       let(:content) { '/assign @abcd1234' }
       let(:issuable) { issue }

spec/support/features/issuable_slash_commands_shared_examples.rb

@@ -63,7 +63,7 @@ shared_examples 'issuable record that supports slash commands in its description
         note = issuable.notes.user.first
 
         expect(note.note).to eq "Awesome!"
-        expect(issuable.assignee).to eq assignee
+        expect(issuable.assignees).to eq [assignee]
         expect(issuable.labels).to eq [label_bug]
         expect(issuable.milestone).to eq milestone
       end
@@ -81,7 +81,7 @@ shared_examples 'issuable record that supports slash commands in its description
         issuable.reload
 
         expect(issuable.notes.user).to be_empty
-        expect(issuable.assignee).to eq assignee
+        expect(issuable.assignees).to eq [assignee]
         expect(issuable.labels).to eq [label_bug]
         expect(issuable.milestone).to eq milestone
       end