Add DiffNote model

app/models/diff_note.rb

+class DiffNote < Note
+  include NoteOnDiff
+
+  serialize :original_position, Gitlab::Diff::Position
+  serialize :position, Gitlab::Diff::Position
+
+  validates :original_position, presence: true
+  validates :position, presence: true
+  validates :diff_line, presence: true
+  validates :line_code, presence: true, line_code: true
+  validates :noteable_type, inclusion: { in: ['Commit', 'MergeRequest'] }
+  validate :positions_complete
+  validate :verify_supported
+
+  before_validation :set_original_position, on: :create
+  before_validation :set_line_code
+
+  class << self
+    def build_discussion_id(noteable_type, noteable_id, position)
+      [super(noteable_type, noteable_id), *position.key].join("-")
+    end
+  end
+
+  def new_diff_note?
+    true
+  end
+
+  def diff_attributes
+    { position: position.to_json }
+  end
+
+  def discussion_id
+    @discussion_id ||= self.class.build_discussion_id(noteable_type, noteable_id || commit_id, position)
+  end
+
+  def original_discussion_id
+    @original_discussion_id ||= self.class.build_discussion_id(noteable_type, noteable_id || commit_id, original_position)
+  end
+
+  def position=(new_position)
+    if new_position.is_a?(String)
+      new_position = JSON.parse(new_position) rescue nil
+    end
+
+    if new_position.is_a?(Hash)
+      new_position = new_position.with_indifferent_access
+      new_position = Gitlab::Diff::Position.new(new_position)
+    end
+
+    super(new_position)
+  end
+
+  def diff_file
+    @diff_file ||= self.original_position.diff_file(self.project.repository)
+  end
+
+  def diff_line
+    @diff_line ||= diff_file.line_for_position(self.original_position) if diff_file
+  end
+
+  def for_line?(line)
+    diff_file.position(line) == self.original_position
+  end
+
+  def active?(diff_refs = nil)
+    return false unless supported?
+    return true if for_commit?
+
+    diff_refs ||= self.noteable.diff_refs
+
+    self.position.diff_refs == diff_refs
+  end
+
+  private
+
+  def supported?
+    !self.for_merge_request?
+  end
+
+  def set_original_position
+    self.original_position = self.position.dup
+  end
+
+  def set_line_code
+    self.line_code = self.position.line_code(self.project.repository)
+  end
+
+  def verify_supported
+    return if supported?
+
+    errors.add(:noteable, "doesn't support new-style diff notes")
+  end
+
+  def positions_complete
+    return if self.original_position.complete? && self.position.complete?
+
+    errors.add(:position, "is invalid")
+  end
+end

app/models/note.rb

@@ -56,7 +56,7 @@ class Note < ActiveRecord::Base
   scope :inc_author, ->{ includes(:author) }
   scope :inc_author_project_award_emoji, ->{ includes(:project, :author, :award_emoji) }
 
-  scope :legacy_diff_notes, ->{ where(type: 'LegacyDiffNote') }
+  scope :diff_notes, ->{ where(type: ['LegacyDiffNote', 'DiffNote']) }
   scope :non_diff_notes, ->{ where(type: ['Note', nil]) }
 
   scope :with_associations, -> do
@@ -82,7 +82,7 @@ class Note < ActiveRecord::Base
     end
 
     def grouped_diff_notes
-      legacy_diff_notes.select(&:active?).sort_by(&:created_at).group_by(&:line_code)
+      diff_notes.select(&:active?).sort_by(&:created_at).group_by(&:line_code)
     end
 
     # Searches for notes matching the given query.
@@ -115,6 +115,10 @@ class Note < ActiveRecord::Base
     false
   end
 
+  def new_diff_note?
+    false
+  end
+
   def active?
     true
   end

db/migrate/20160508215920_add_positions_to_diff_notes.rb

+class AddPositionsToDiffNotes < ActiveRecord::Migration
+  def change
+    add_column :notes, :position, :text
+    add_column :notes, :original_position, :text
+  end
+end

features/steps/project/merge_requests.rb

@@ -272,10 +272,9 @@ class Spinach::Features::ProjectMergeRequests < Spinach::FeatureSteps
 
   step 'user "John Doe" leaves a comment like "Line is wrong" on diff' do
     mr = MergeRequest.find_by(title: "Bug NS-05")
-    create(:note_on_merge_request_diff, project: project,
+    create(:diff_note_on_merge_request, project: project,
                                         noteable: mr,
                                         author: user_exists("John Doe"),
-                                        line_code: sample_commit.line_code,
                                         note: 'Line is wrong')
   end
 

spec/factories/notes.rb

@@ -10,21 +10,46 @@ FactoryGirl.define do
     on_issue
 
     factory :note_on_commit,             traits: [:on_commit]
-    factory :note_on_commit_diff,        traits: [:on_commit, :on_diff], class: LegacyDiffNote
     factory :note_on_issue,              traits: [:on_issue], aliases: [:votable_note]
     factory :note_on_merge_request,      traits: [:on_merge_request]
-    factory :note_on_merge_request_diff, traits: [:on_merge_request, :on_diff], class: LegacyDiffNote
     factory :note_on_project_snippet,    traits: [:on_project_snippet]
     factory :system_note,                traits: [:system]
 
+    factory :legacy_diff_note_on_commit, traits: [:on_commit, :legacy_diff_note], class: LegacyDiffNote
+    factory :legacy_diff_note_on_merge_request, traits: [:on_merge_request, :legacy_diff_note], class: LegacyDiffNote
+
+    factory :diff_note_on_merge_request, traits: [:on_merge_request], class: DiffNote do
+      position do
+        Gitlab::Diff::Position.new(
+          old_path: "files/ruby/popen.rb",
+          new_path: "files/ruby/popen.rb",
+          old_line: nil,
+          new_line: 14,
+          diff_refs: noteable.diff_refs
+        )
+      end
+    end
+
+    factory :diff_note_on_commit, traits: [:on_commit], class: DiffNote do
+      position do
+        Gitlab::Diff::Position.new(
+          old_path: "files/ruby/popen.rb",
+          new_path: "files/ruby/popen.rb",
+          old_line: nil,
+          new_line: 14,
+          diff_refs: project.commit(commit_id).try(:diff_refs)
+        )
+      end
+    end
+
     trait :on_commit do
       noteable nil
-      noteable_id nil
       noteable_type 'Commit'
+      noteable_id nil
       commit_id RepoHelpers.sample_commit.id
     end
 
-    trait :on_diff do
+    trait :legacy_diff_note do
       line_code "0_184_184"
     end
 

spec/lib/gitlab/note_data_builder_spec.rb

@@ -27,7 +27,7 @@ describe 'Gitlab::NoteDataBuilder', lib: true do
   end
 
   describe 'When asking for a note on commit diff' do
-    let(:note) { create(:note_on_commit_diff, project: project) }
+    let(:note) { create(:diff_note_on_commit, project: project) }
 
     it 'returns the note and commit-specific data' do
       expect(data).to have_key(:commit)
@@ -90,7 +90,7 @@ describe 'Gitlab::NoteDataBuilder', lib: true do
     end
 
     let(:note) do
-      create(:note_on_merge_request_diff, noteable: merge_request,
+      create(:diff_note_on_merge_request, noteable: merge_request,
                                           project: project)
     end
 

spec/lib/gitlab/url_builder_spec.rb

@@ -43,9 +43,9 @@ describe Gitlab::UrlBuilder, lib: true do
         end
       end
 
-      context 'on a CommitDiff' do
+      context 'on a Commit Diff' do
         it 'returns a proper URL' do
-          note = build_stubbed(:note_on_commit_diff)
+          note = build_stubbed(:diff_note_on_commit)
 
           url = described_class.build(note)
 
@@ -75,10 +75,10 @@ describe Gitlab::UrlBuilder, lib: true do
         end
       end
 
-      context 'on a MergeRequestDiff' do
+      context 'on a MergeRequest Diff' do
         it 'returns a proper URL' do
           merge_request = create(:merge_request, iid: 42)
-          note = build_stubbed(:note_on_merge_request_diff, noteable: merge_request)
+          note = build_stubbed(:diff_note_on_merge_request, noteable: merge_request)
 
           url = described_class.build(note)
 

spec/models/legacy_diff_note_spec.rb

@@ -2,7 +2,7 @@ require 'spec_helper'
 
 describe LegacyDiffNote, models: true do
   describe "Commit diff line notes" do
-    let!(:note) { create(:note_on_commit_diff, note: "+1 from me") }
+    let!(:note) { create(:legacy_diff_note_on_commit, note: "+1 from me") }
     let!(:commit) { note.noteable }
 
     it "should save a valid note" do
@@ -17,7 +17,7 @@ describe LegacyDiffNote, models: true do
 
   describe '#active?' do
     it 'is always true when the note has no associated diff' do
-      note = build(:note_on_merge_request_diff)
+      note = build(:legacy_diff_note_on_merge_request)
 
       expect(note).to receive(:diff).and_return(nil)
 
@@ -25,7 +25,7 @@ describe LegacyDiffNote, models: true do
     end
 
     it 'is never true when the note has no noteable associated' do
-      note = build(:note_on_merge_request_diff)
+      note = build(:legacy_diff_note_on_merge_request)
 
       expect(note).to receive(:diff).and_return(double)
       expect(note).to receive(:noteable).and_return(nil)
@@ -34,7 +34,7 @@ describe LegacyDiffNote, models: true do
     end
 
     it 'returns the memoized value if defined' do
-      note = build(:note_on_merge_request_diff)
+      note = build(:legacy_diff_note_on_merge_request)
 
       note.instance_variable_set(:@active, 'foo')
       expect(note).not_to receive(:find_noteable_diff)
@@ -45,7 +45,7 @@ describe LegacyDiffNote, models: true do
     context 'for a merge request noteable' do
       it 'is false when noteable has no matching diff' do
         merge = build_stubbed(:merge_request, :simple)
-        note = build(:note_on_merge_request_diff, noteable: merge)
+        note = build(:legacy_diff_note_on_merge_request, noteable: merge)
 
         allow(note).to receive(:diff).and_return(double)
         expect(note).to receive(:find_noteable_diff).and_return(nil)
@@ -63,9 +63,9 @@ describe LegacyDiffNote, models: true do
         code = Gitlab::Diff::LineCode.generate(diff.new_path, line.new_pos, line.old_pos)
 
         # We're persisting in order to trigger the set_diff callback
-        note = create(:note_on_merge_request_diff, noteable: merge,
-                                                   line_code: code,
-                                                   project: merge.source_project)
+        note = create(:legacy_diff_note_on_merge_request,  noteable: merge,
+                                                           line_code: code,
+                                                           project: merge.source_project)
 
         # Make sure we don't get a false positive from a guard clause
         expect(note).to receive(:find_noteable_diff).and_call_original