Merge when build succeeds

17 files changed, 219 insertions, 20 deletions

diff --git a/CHANGELOG b/CHANGELOG
index 0d89fca9fc1..195e53abd8b 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -14,6 +14,7 @@ v 8.2.0 (unreleased)
   - Fix: 500 error returned if destroy request without HTTP referer (Kazuki Shimizu)
   - Remove deprecated CI events from project settings page
   - Use issue editor as cross reference comment author when issue is edited with a new mention.
+  - Merge when build succeeds (Zeger-Jan van de Weg)
 
 v 8.1.1
   - Fix cloning Wiki repositories via HTTP (Stan Hu)
diff --git a/app/assets/stylesheets/pages/merge_requests.scss b/app/assets/stylesheets/pages/merge_requests.scss
index f0b3667acca..b5a8c893678 100644
--- a/app/assets/stylesheets/pages/merge_requests.scss
+++ b/app/assets/stylesheets/pages/merge_requests.scss
@@ -19,18 +19,20 @@
   .accept-merge-holder {
     .accept-action {
       display: inline-block;
+      float: left;
     }
 
     .accept-control {
       display: inline-block;
+      float: left;
       margin: 0;
       margin-left: 20px;
       padding: 5px;
+      padding-top: 12px;
       line-height: 20px;
 
       &.right {
         float: right;
-        padding-top: 12px;
         a {
           color: $gl-gray;
         }
diff --git a/app/controllers/projects/merge_requests_controller.rb b/app/controllers/projects/merge_requests_controller.rb
index 16c42386623..2f9b8a25edf 100644
--- a/app/controllers/projects/merge_requests_controller.rb
+++ b/app/controllers/projects/merge_requests_controller.rb
@@ -2,7 +2,7 @@ class Projects::MergeRequestsController < Projects::ApplicationController
   before_action :module_enabled
   before_action :merge_request, only: [
     :edit, :update, :show, :diffs, :commits, :merge, :merge_check,
-    :ci_status, :toggle_subscription
+    :ci_status, :toggle_subscription, :cancel_merge_when_build_succeeds
   ]
   before_action :closes_issues, only: [:edit, :update, :show, :diffs, :commits]
   before_action :validates_merge_request, only: [:show, :diffs, :commits]
@@ -149,15 +149,34 @@ class Projects::MergeRequestsController < Projects::ApplicationController
     render partial: "projects/merge_requests/widget/show.html.haml", layout: false
   end
 
+  def cancel_merge_when_build_succeeds
+    return access_denied! unless @merge_request.can_be_merged_by?(current_user)
+
+    if @merge_request.merge_when_build_succeeds?
+      @merge_request.reset_merge_when_build_succeeds
+      SystemNoteService.cancel_merge_when_build_succeeds(merge_request, @project, @current_user)
+    end
+  end
+
   def merge
     return access_denied! unless @merge_request.can_be_merged_by?(current_user)
 
-    if @merge_request.mergeable?
-      @merge_request.update(merge_error: nil)
-      MergeWorker.perform_async(@merge_request.id, current_user.id, params)
-      @status = true
+    unless @merge_request.mergeable?
+      @status = :failed
+      return
+    end
+
+    @merge_request.update(merge_error: nil)
+
+    if params[:merge_when_build_succeeds] && @merge_request.ci_commit.active?
+      MergeRequests::MergeWhenBuildSucceedsService.new(@project,
+                                                      current_user,
+                                                      merge_params: merge_params)
+                                                      .execute(@merge_request)
+      @status = :merge_when_build_succeeds
     else
-      @status = false
+      MergeWorker.perform_async(@merge_request.id, current_user.id, params)
+      @status = :success
     end
   end
 
@@ -282,6 +301,10 @@ class Projects::MergeRequestsController < Projects::ApplicationController
     )
   end
 
+  def merge_params
+    params.permit(:should_remove_source_branch, :commit_message)
+  end
+
   # Make sure merge requests created before 8.0
   # have head file in refs/merge-requests/
   def ensure_ref_fetched
diff --git a/app/models/ci/commit.rb b/app/models/ci/commit.rb
index 13437b2483f..ebe4bace3b5 100644
--- a/app/models/ci/commit.rb
+++ b/app/models/ci/commit.rb
@@ -164,6 +164,14 @@ module Ci
       status == 'canceled'
     end
 
+    def active?
+      running? || pending?
+    end
+
+    def complete?
+      canceled? || success? || failed?
+    end
+
     def duration
       duration_array = latest_statuses.map(&:duration).compact
       duration_array.reduce(:+).to_i
diff --git a/app/models/commit_status.rb b/app/models/commit_status.rb
index 0b73ab6d2eb..b1049fab788 100644
--- a/app/models/commit_status.rb
+++ b/app/models/commit_status.rb
@@ -1,3 +1,32 @@
+# == Schema Information
+#
+#  project_id            integer
+#  status                string
+#  finished_at           datetime
+#  trace                 text
+#  created_at            datetime
+#  updated_at            datetime
+#  started_at            datetime
+#  runner_id             integer
+#  coverage              float
+#  commit_id             integer
+#  commands              text
+#  job_id                integer
+#  name                  string
+#  deploy                boolean           default: false
+#  options               text
+#  allow_failure         boolean           default: false, null: false
+#  stage                 string
+#  trigger_request_id    integer
+#  stage_idx             integer
+#  tag                   boolean
+#  ref                   string
+#  user_id               integer
+#  type                  string
+#  target_url            string
+#  description           string
+#
+
 class CommitStatus < ActiveRecord::Base
   self.table_name = 'ci_builds'
 
@@ -46,6 +75,10 @@ class CommitStatus < ActiveRecord::Base
       build.update_attributes finished_at: Time.now
     end
 
+    after_transition running: :success do |build, transition|
+      MergeRequests::MergeWhenBuildSucceedsService.new(build.commit.gl_project, nil).trigger(build)
+    end
+
     state :pending, value: 'pending'
     state :running, value: 'running'
     state :failed, value: 'failed'
diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index 85f37e49e62..c5f04dbcf4c 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -34,9 +34,12 @@ class MergeRequest < ActiveRecord::Base
 
   belongs_to :target_project, foreign_key: :target_project_id, class_name: "Project"
   belongs_to :source_project, foreign_key: :source_project_id, class_name: "Project"
+  belongs_to :merge_user, class_name: "User"
 
   has_one :merge_request_diff, dependent: :destroy
 
+  serialize :merge_params, Hash
+
   after_create :create_merge_request_diff
   after_update :update_merge_request_diff
 
@@ -385,6 +388,16 @@ class MergeRequest < ActiveRecord::Base
     message
   end
 
+  def reset_merge_when_build_succeeds
+    return unless merge_when_build_succeeds?
+    
+    self.merge_when_build_succeeds = false
+    self.merge_user = nil
+    self.merge_params = nil
+
+    self.save
+  end
+
   # Return array of possible target branches
   # depends on target project of MR
   def target_branches
diff --git a/app/services/merge_requests/merge_when_build_succeeds_service.rb b/app/services/merge_requests/merge_when_build_succeeds_service.rb
new file mode 100644
index 00000000000..a4418360b8c
--- /dev/null
+++ b/app/services/merge_requests/merge_when_build_succeeds_service.rb
@@ -0,0 +1,43 @@
+module MergeRequests
+  class MergeWhenBuildSucceedsService < MergeRequests::BaseService
+    def execute(merge_request)
+      merge_request.merge_params.merge!(params[:merge_params])
+
+      # The service is also called when the merge params are updated.
+      already_approved = merge_request.merge_when_build_succeeds?
+
+      unless already_approved
+        merge_request.merge_when_build_succeeds = true
+        merge_request.merge_user                = @current_user
+      end
+
+      merge_request.save
+
+      unless already_approved
+        SystemNoteService.merge_when_build_succeeds(merge_request, @project, @current_user)
+      end
+    end
+
+    def trigger(build)
+      merge_requests = merge_request_from(build)
+
+      merge_requests.each do |merge_request|
+        next unless merge_request.merge_when_build_succeeds?
+
+        ci_commit = merge_request.ci_commit
+        if ci_commit && ci_commit.success? && merge_request.mergeable?
+          MergeWorker.perform_async(merge_request.id, merge_request.merge_user_id, merge_request.merge_params)
+        end
+      end
+    end
+
+    private
+
+    def merge_request_from(build)
+      merge_requests = @project.origin_merge_requests.opened.where(source_branch: build.ref).to_a
+      merge_requests += @project.fork_merge_requests.opened.where(source_branch: build.ref).to_a
+
+      merge_requests.uniq.select(&:source_project)
+    end
+  end
+end
diff --git a/app/services/merge_requests/refresh_service.rb b/app/services/merge_requests/refresh_service.rb
index d68bc79ecc0..335ef32abce 100644
--- a/app/services/merge_requests/refresh_service.rb
+++ b/app/services/merge_requests/refresh_service.rb
@@ -8,6 +8,7 @@ module MergeRequests
 
       find_new_commits
       reload_merge_requests
+      reset_merge_when_build_succeeds
 
       # Leave a system note if a branch was deleted/added
       if branch_added? || branch_removed?
@@ -57,7 +58,6 @@ module MergeRequests
       merge_requests = filter_merge_requests(merge_requests)
 
       merge_requests.each do |merge_request|
-
         if merge_request.source_branch == @branch_name || force_push?
           merge_request.reload_code
           merge_request.mark_as_unchecked
@@ -76,6 +76,12 @@ module MergeRequests
       end
     end
 
+    def reset_merge_when_build_succeeds
+      merge_requests_for_source_branch.each do |merge_request|
+        merge_request.reset_merge_when_build_succeeds
+      end
+    end
+
     def find_new_commits
       if branch_added?
         @commits = []
diff --git a/app/services/system_note_service.rb b/app/services/system_note_service.rb
index 708c2f00486..c9846e9f26f 100644
--- a/app/services/system_note_service.rb
+++ b/app/services/system_note_service.rb
@@ -130,6 +130,20 @@ class SystemNoteService
     create_note(noteable: noteable, project: project, author: author, note: body)
   end
 
+  # Called when 'merge when build succeeds' is executed
+  def self.merge_when_build_succeeds(noteable, project, author)
+    body = "Approved this request to be merged automatically when the build succeeds"
+
+    create_note(noteable: noteable, project: project, author: author, note: body)
+  end
+
+  # Called when 'merge when build succeeds' is canceled
+  def self.cancel_merge_when_build_succeeds(noteable, project, author)
+    body = "Canceled the automatic merge"
+
+    create_note(noteable: noteable, project: project, author: author, note: body)
+  end
+
   # Called when the title of a Noteable is changed
   #
   # noteable  - Noteable object that responds to `title`
diff --git a/app/views/projects/merge_requests/cancel_merge_when_build_succeeds.js.haml b/app/views/projects/merge_requests/cancel_merge_when_build_succeeds.js.haml
new file mode 100644
index 00000000000..eab5be488b5
--- /dev/null
+++ b/app/views/projects/merge_requests/cancel_merge_when_build_succeeds.js.haml
@@ -0,0 +1,2 @@
+:plain
+  $('.mr-widget-body').html("#{escape_javascript(render('projects/merge_requests/widget/open/accept'))}");
diff --git a/app/views/projects/merge_requests/merge.js.haml b/app/views/projects/merge_requests/merge.js.haml
index 33321651e32..89aae17a606 100644
--- a/app/views/projects/merge_requests/merge.js.haml
+++ b/app/views/projects/merge_requests/merge.js.haml
@@ -1,6 +1,10 @@
-- if @status
+- case @status
+- when :success 
   :plain
     merge_request_widget.mergeInProgress();
+- when :merge_when_build_succeeds
+  :plain
+    $('.mr-widget-body').html("#{escape_javascript(render('projects/merge_requests/widget/open/merge_when_build_succeeds'))}");
 - else
   :plain
     $('.mr-widget-body').html("#{escape_javascript(render('projects/merge_requests/widget/open/reload'))}");
diff --git a/app/views/projects/merge_requests/widget/_open.html.haml b/app/views/projects/merge_requests/widget/_open.html.haml
index 0aad9bb3e88..e0013fb769a 100644
--- a/app/views/projects/merge_requests/widget/_open.html.haml
+++ b/app/views/projects/merge_requests/widget/_open.html.haml
@@ -13,6 +13,8 @@
       = render 'projects/merge_requests/widget/open/conflicts'
     - elsif @merge_request.work_in_progress?
       = render 'projects/merge_requests/widget/open/wip'
+    - elsif @merge_request.merge_when_build_succeeds?
+      = render 'projects/merge_requests/widget/open/merge_when_build_succeeds'
     - elsif !@merge_request.can_be_merged_by?(current_user)
       = render 'projects/merge_requests/widget/open/not_allowed'
     - elsif @merge_request.can_be_merged?
diff --git a/app/views/projects/merge_requests/widget/open/_accept.html.haml b/app/views/projects/merge_requests/widget/open/_accept.html.haml
index 613525437ab..2afc5f81251 100644
--- a/app/views/projects/merge_requests/widget/open/_accept.html.haml
+++ b/app/views/projects/merge_requests/widget/open/_accept.html.haml
@@ -2,8 +2,15 @@
   = hidden_field_tag :authenticity_token, form_authenticity_token
   .accept-merge-holder.clearfix.js-toggle-container
     .accept-action
-      = f.button class: "btn btn-create accept_merge_request" do
-        Accept Merge Request
+      - ci_commit = @merge_request.ci_commit
+      - if ci_commit && ci_commit.active?
+        = f.button class: "btn btn-create btn-grouped merge_when_build_succeeds", name: "merge_when_build_succeeds" do
+          Merge when Build Succeeds
+        = f.button class: "btn btn-warning btn-grouped accept_merge_request" do
+          Accept Merge Request Now
+      - else
+        = f.button class: "btn btn-create btn-grouped accept_merge_request" do
+          Accept Merge Request
     - if can_remove_branch?(@merge_request.source_project, @merge_request.source_branch) && !@merge_request.for_fork?
       .accept-control.checkbox
         = label_tag :should_remove_source_branch, class: "remove_source_checkbox" do
@@ -19,7 +26,8 @@
           rows: 14, hint: true
 
   :coffeescript
-    $('.accept-mr-form').on 'ajax:before', ->
-      btn = $('.accept_merge_request')
-      btn.disable()
+    $('.accept_merge_request').on 'click', ->
+      btn = $(this)
       btn.html("<i class='fa fa-spinner fa-spin'></i> Merge in progress")
+    $('.accept-mr-form').on 'ajax:sen', ->
+      $(".accept-mr-form :input").disable()
diff --git a/app/views/projects/merge_requests/widget/open/_merge_when_build_succeeds.html.haml b/app/views/projects/merge_requests/widget/open/_merge_when_build_succeeds.html.haml
new file mode 100644
index 00000000000..7e5385cf8b9
--- /dev/null
+++ b/app/views/projects/merge_requests/widget/open/_merge_when_build_succeeds.html.haml
@@ -0,0 +1,27 @@
+%h4
+  Approved by #{link_to_member(@project, @merge_request.merge_user, avatar: true)}
+  to be merged automatically when
+  #{link_to "the build", ci_status_path(@merge_request.ci_commit)} succeeds
+%div
+  - if @merge_request.merge_params["should_remove_source_branch"]
+    = succeed '.' do
+      The changes will be merged into
+      %span.label-branch= @merge_request.target_branch
+    The source branch will be removed.
+  - elsif can_remove_branch?(@merge_request.source_project, @merge_request.source_branch)
+    - remove_source_branch_button = true
+    %p
+      = succeed '.' do
+        The changes will be merged into
+        %span.label-branch= @merge_request.target_branch
+      The source branch will not be removed.
+
+- if remove_source_branch_button || @merge_request.can_be_merged_by?(current_user)
+  .clearfix.prepend-top-10
+    - if remove_source_branch_button
+      = link_to merge_namespace_project_merge_request_path(@merge_request.source_project.namespace, @merge_request.source_project, @merge_request, merge_when_build_succeeds: true, should_remove_source_branch: true), remote: true, method: :post, class: "btn btn-grouped btn-primary btn-sm remove_source_branch" do
+        = icon('times')
+        Remove Source Branch When Merged
+    - if @merge_request.can_be_merged_by?(current_user)
+      = link_to merge_namespace_project_merge_request_path(@merge_request.source_project.namespace, @merge_request.source_project, @merge_request), remote: true, method: :delete, class: "btn btn-grouped btn-warning btn-sm" do
+        Cancel Automatic Merge
diff --git a/config/routes.rb b/config/routes.rb
index 0458f538eb6..917c3d3f1ed 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -556,6 +556,7 @@ Gitlab::Application.routes.draw do
             get :diffs
             get :commits
             post :merge
+            delete :merge, action: :cancel_merge_when_build_succeeds
             get :merge_check
             get :ci_status
             post :toggle_subscription
diff --git a/db/migrate/20151028152939_add_merge_when_build_succeeds_to_merge_request.rb b/db/migrate/20151028152939_add_merge_when_build_succeeds_to_merge_request.rb
new file mode 100644
index 00000000000..ceb52f0c222
--- /dev/null
+++ b/db/migrate/20151028152939_add_merge_when_build_succeeds_to_merge_request.rb
@@ -0,0 +1,7 @@
+class AddMergeWhenBuildSucceedsToMergeRequest < ActiveRecord::Migration
+  def change
+    add_column :merge_requests, :merge_params, :text
+    add_column :merge_requests, :merge_when_build_succeeds, :boolean, default: false, null: false
+    add_column :merge_requests, :merge_user_id, :integer
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 4bde9f0b748..825d95565be 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20151026182941) do
+ActiveRecord::Schema.define(version: 20151028152939) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -418,6 +418,7 @@ ActiveRecord::Schema.define(version: 20151026182941) do
   end
 
   add_index "labels", ["project_id"], name: "index_labels_on_project_id", using: :btree
+  add_index "labels", ["title"], name: "index_labels_on_title", using: :btree
 
   create_table "members", force: true do |t|
     t.integer  "access_level",       null: false
@@ -453,9 +454,9 @@ ActiveRecord::Schema.define(version: 20151026182941) do
   add_index "merge_request_diffs", ["merge_request_id"], name: "index_merge_request_diffs_on_merge_request_id", unique: true, using: :btree
 
   create_table "merge_requests", force: true do |t|
-    t.string   "target_branch",                 null: false
-    t.string   "source_branch",                 null: false
-    t.integer  "source_project_id",             null: false
+    t.string   "target_branch",                             null: false
+    t.string   "source_branch",                             null: false
+    t.integer  "source_project_id",                         null: false
     t.integer  "author_id"
     t.integer  "assignee_id"
     t.string   "title"
@@ -464,13 +465,16 @@ ActiveRecord::Schema.define(version: 20151026182941) do
     t.integer  "milestone_id"
     t.string   "state"
     t.string   "merge_status"
-    t.integer  "target_project_id",             null: false
+    t.integer  "target_project_id",                         null: false
     t.integer  "iid"
     t.text     "description"
-    t.integer  "position",          default: 0
+    t.integer  "position",                  default: 0
     t.datetime "locked_at"
     t.integer  "updated_by_id"
     t.string   "merge_error"
+    t.text     "merge_params"
+    t.boolean  "merge_when_build_succeeds", default: false, null: false
+    t.integer  "merge_user_id"
   end
 
   add_index "merge_requests", ["assignee_id"], name: "index_merge_requests_on_assignee_id", using: :btree
@@ -499,6 +503,7 @@ ActiveRecord::Schema.define(version: 20151026182941) do
   add_index "milestones", ["due_date"], name: "index_milestones_on_due_date", using: :btree
   add_index "milestones", ["project_id", "iid"], name: "index_milestones_on_project_id_and_iid", unique: true, using: :btree
   add_index "milestones", ["project_id"], name: "index_milestones_on_project_id", using: :btree
+  add_index "milestones", ["title"], name: "index_milestones_on_title", using: :btree
 
   create_table "namespaces", force: true do |t|
     t.string   "name",                     null: false