Add likes to merge requests.

Thsi fix the issue #85.

app/controllers/merge_requests_controller.rb

@@ -12,6 +12,7 @@ def update
     when 'accept' then accept
     when 'abandon' then abandon
     else
+      @mr.likes.create(user: current_user) if params[:mr_action] == 'like'
       redirect_to(redir_params)
     end
   rescue RuntimeError => e

app/helpers/merge_requests_helper.rb

@@ -13,8 +13,11 @@ def patch_linter_status(patch)
   end
 
   def author_sentence(mr)
-    closed_info = mr.closed? ? ", #{@mr.status} by <strong>#{@mr.reviewer.name}</strong>." : ''
-    "Authored by <strong>#{mr.author.name}</strong>#{closed_info}".html_safe
+    closed_info = mr.closed? ? ", #{@mr.status} by <strong>#{@mr.reviewer.name}</strong>" : ''
+    likes = User.joins(:likes).where(likes: { merge_request: mr }).pluck(:name).to_sentence
+    likes = "<br>Looks good to: <em>#{likes}</em>." if likes.present?
+
+    "Authored by <strong>#{mr.author.name}</strong>#{closed_info}.#{likes}".html_safe
   end
 
   def search_request?

app/models/like.rb

@@ -0,0 +1,6 @@
+class Like < ApplicationRecord
+  belongs_to :merge_request
+  belongs_to :user
+
+  validates :user_id, uniqueness: { scope: :merge_request_id }
+end

app/models/merge_request.rb

@@ -11,6 +11,7 @@ class MergeRequest < ApplicationRecord
 
   has_many :patches, -> { order(:created_at) }, dependent: :destroy
   has_many :history_events, -> { order(:when) }, dependent: :destroy
+  has_many :likes, dependent: :destroy
 
   enum status: %i(open integrating needs_rebase accepted abandoned)
 

app/models/patch.rb

@@ -11,6 +11,7 @@ class Patch < ApplicationRecord
   validates :commit_message, length: { minimum: 0 }, allow_nil: false
 
   after_create :update_jira_ticket
+  after_create :reset_likes
   after_commit :really_push_to_ci, on: :create, unless: :canceled?
 
   delegate :author, to: :merge_request
@@ -88,4 +89,8 @@ def update_jira_ticket(silent: false)
     merge_request.notify_jira if !silent && merge_request.jira_ticket_changed?
     merge_request.save!
   end
+
+  def reset_likes
+    merge_request.likes.delete_all
+  end
 end

app/models/user.rb

@@ -7,6 +7,7 @@ class User < ApplicationRecord
 
   before_create :generate_api_token
   has_many :comments
+  has_many :likes
   has_many :merge_requests, foreign_key: :author_id
   has_many :patches, through: :merge_requests
   has_many :locked_branches, foreign_key: :who_id

app/views/merge_requests/_summary.html.haml

@@ -1,6 +1,7 @@
 .ui.top.attached.segment
   .markdown= @patch.commit_message
-.ui.bottom.attached.warning.message= author_sentence(@mr)
+.ui.bottom.attached.warning.message
+  = author_sentence(@mr)
 
 #summary-bar.ui.statistics{ class: @project.gitlab_ci? ? 'five' : 'four' }
   - if @project.gitlab_ci?

app/views/merge_requests/show.html.haml

@@ -48,6 +48,9 @@
         %button#accept.ui.button{ type: 'button'} Accept
       %button#abandon.ui.red.button{ type: 'button'} Abandon
     %input#mr_action.ui.primary.button.push-comments{ name: 'mr_action', type: 'submit', value: 'Just push comments' }
+    #like.ui.icon.button.primary.push-comments
+      %i.thumbs.up.icon
+
 
   #accept-modal.ui.basic.modal
     .ui.icon.header

app/webpacker/src/javascript/merge_requests.js

@@ -18,6 +18,7 @@ export default function merge_requests() {
     });
     $('#accept').on('click', function(event) { showSubmitModal('accept'); });
     $('#abandon').on('click', function(event) { showSubmitModal('abandon'); });
+    $('#like').on('click', function(event) { like(event); });
     $('#accept-model-button').on('mouseover', function(event) { $('.js-tada').transition('tada'); });
     if ($('textarea').length > 0)
         new_editor($('textarea').get(0), false);
@@ -33,6 +34,12 @@ function showSubmitModal(action) {
     }}).modal('show')
 }
 
+function like(event) {
+    $('#mr_action').val('like');
+    $('#mr-form').submit();
+    return false;
+}
+
 function request_patch_diff(event) {
     var form = $(event.target.form)
     var query = '?';

db/migrate/20190824211848_add_likes_to_merge_requests.rb

@@ -0,0 +1,11 @@
+class AddLikesToMergeRequests < ActiveRecord::Migration[5.2]
+  def change
+    create_table :likes do |t|
+      t.references :user, null: false
+      t.references :merge_request, null: false
+      t.timestamps null: false
+    end
+
+    add_index :likes, %i(user_id merge_request_id), unique: true
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2019_08_24_052620) do
+ActiveRecord::Schema.define(version: 2019_08_24_211848) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "hstore"
@@ -37,6 +37,16 @@
     t.index ["who_id"], name: "index_history_events_on_who_id"
   end
 
+  create_table "likes", force: :cascade do |t|
+    t.bigint "user_id", null: false
+    t.bigint "merge_request_id", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["merge_request_id"], name: "index_likes_on_merge_request_id"
+    t.index ["user_id", "merge_request_id"], name: "index_likes_on_user_id_and_merge_request_id", unique: true
+    t.index ["user_id"], name: "index_likes_on_user_id"
+  end
+
   create_table "locked_branches", id: :serial, force: :cascade do |t|
     t.integer "project_id", null: false
     t.integer "who_id", null: false

spec/models/merge_request_spec.rb

@@ -0,0 +1,22 @@
+describe MergeRequest do
+  let(:user) { create(:user) }
+  let(:mr)   { create(:merge_request) }
+  let(:mr2)  { create(:merge_request) }
+
+  it 'do reset likes from a merge request after a patch being added to it' do
+    mr2.likes.create(user: user)
+    mr.likes.create(user: user)
+    expect(mr.likes.count).to eq(1)
+    expect(mr2.likes.count).to eq(1)
+
+    create(:patch, merge_request: mr)
+    expect(mr.likes.count).to eq(0)
+    expect(mr2.likes.count).to eq(1)
+  end
+
+  it 'forbid more than one like per merge request' do
+    mr.likes.create(user: user)
+    like = mr.likes.build(user: user)
+    expect(like.save).to eq(false)
+  end
+end