Add model to track merges made while detecting conflicts

app/models/merge.rb

@@ -0,0 +1,35 @@
+class Merge < ActiveRecord::Base
+  fields do
+    timestamps
+  end
+
+  belongs_to :source_branch, class_name: Branch, required: true
+  belongs_to :target_branch, class_name: Branch, required: true
+  has_one :repository, through: :source_branch
+
+  validates :source_branch, :target_branch, presence: true
+  validates :source_branch, uniqueness: { scope: :target_branch, message: "Merges must be unique" }
+  validates_each :source_branch do |record, attr, value|
+    # specifically ignore nil branches, those will be caught by a different validator
+    if (value.present? && record.target_branch.present?)
+      if value.id == record.target_branch.id
+        record.errors.add(attr, 'Branch cannot merge with itself')
+      end
+      if value.repository.id != record.target_branch.repository.id
+        record.errors.add(attr, 'Branches from different repositories cannot be merged')
+      end
+    end
+  end
+
+  scope :by_target_user, lambda { |user|
+    joins(:target_branch).where(
+      '(branches.author_id = ?)',
+      user.id)
+  }
+
+  scope :created_after, lambda { |after_date|
+    where('created_at >= ?', after_date)
+  }
+
+  scope :from_repository, lambda { |repository_name| joins(:repository).where("repositories.name = ?", repository_name) }
+end

db/migrate/20151227045135_hobo_migration_14.rb

@@ -0,0 +1,16 @@
+class HoboMigration14 < ActiveRecord::Migration
+  def self.up
+    create_table :merges do |t|
+      t.datetime :created_at
+      t.datetime :updated_at
+      t.integer  :source_branch_id
+      t.integer  :target_branch_id
+    end
+    add_index :merges, [:source_branch_id]
+    add_index :merges, [:target_branch_id]
+  end
+
+  def self.down
+    drop_table :merges
+  end
+end

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: 20151220025330) do
+ActiveRecord::Schema.define(version: 20151227045135) do
 
   create_table "branches", force: :cascade do |t|
     t.datetime "git_tested_at"
@@ -39,6 +39,16 @@
   add_index "conflicts", ["branch_a_id"], name: "index_conflicts_on_branch_a_id"
   add_index "conflicts", ["branch_b_id"], name: "index_conflicts_on_branch_b_id"
 
+  create_table "merges", force: :cascade do |t|
+    t.datetime "created_at"
+    t.datetime "updated_at"
+    t.integer  "source_branch_id"
+    t.integer  "target_branch_id"
+  end
+
+  add_index "merges", ["source_branch_id"], name: "index_merges_on_source_branch_id"
+  add_index "merges", ["target_branch_id"], name: "index_merges_on_target_branch_id"
+
   create_table "notification_suppressions", force: :cascade do |t|
     t.datetime "suppress_until"
     t.datetime "created_at"

lib/conflict_detector.rb

@@ -105,7 +105,9 @@ def get_conflicts(target_branch, source_branches)
         Rails.logger.info("MERGED: #{source_branch.name} can be merged into #{target_branch.name} without conflicts")
         if should_push_merged_branch?(target_branch, source_branch)
           Rails.logger.info("PUSHING: #{target_branch.name} to origin")
-          @git.push
+          if @git.push
+            Merge.create!(source_branch: source_branch, target_branch: target_branch)
+          end
         end
       else
         if should_ignore_conflicts?(conflict.conflicting_files)
@@ -148,6 +150,9 @@ def exclude_tested_branches(branch_to_test, branches_to_test, tested_pairs)
   end
 
   def test_branches(untested_branches, start_time)
+    # destroy record of previous merges
+    Merge.destroy_all
+
     tested_pairs = []
     all_branches = Branch.all
     untested_branches.each do |branch|

spec/lib/conflict_detector_spec.rb

@@ -125,11 +125,16 @@ def expect_get_conflicts_equals(
         allow_any_instance_of(Git::Git).to receive(:detect_conflicts).and_return(nil)
       end
       if expected_push_count > 0
-        expect_any_instance_of(Git::Git).to receive(:push).exactly(expected_push_count).times
+        expect_any_instance_of(Git::Git).to receive(:push).exactly(expected_push_count).times.and_return(true)
       else
         expect_any_instance_of(Git::Git).not_to receive(:push)
       end
       expect(conflict_detector.send(:get_conflicts, target_branch, source_branches)).to match_array(expected_conflict_list)
+      if expected_push_count > 0
+        expect(Merge.count).to eq(expected_push_count)
+      else
+        expect(Merge.count).to eq(0)
+      end
     end
 
     it 'should include all conflicts when the "ignore files" list is empty' do

spec/models/merge_spec.rb

@@ -0,0 +1,71 @@
+require 'spec_helper'
+
+describe 'Merge' do
+
+  DIFFERENT_NAME = 'Different Name'
+
+  before do
+    @branches = create_test_branches(author_name: 'Author Name', count: 3)
+  end
+
+  it 'can be created' do
+    create_test_merge(@branches[0], @branches[1])
+    expect(Merge.all.size).to eq(1)
+  end
+
+  it 'does not allow duplicate merges' do
+    create_test_merge(@branches[0], @branches[1])
+    expect { create_test_merge(@branches[0], @branches[1]) }.to raise_exception(ActiveRecord::RecordInvalid)
+  end
+
+  it 'cannot merge with itself' do
+    expect { create_test_merge(@branches[0], @branches[0]) }.to raise_exception(ActiveRecord::RecordInvalid)
+  end
+
+  it 'requires two branches' do
+    expect { create_test_merge(@branches[0], nil) }.to raise_exception(ActiveRecord::RecordInvalid)
+    expect { create_test_merge(nil, @branches[0]) }.to raise_exception(ActiveRecord::RecordInvalid)
+    expect { create_test_merge(nil, nil) }.to raise_exception(ActiveRecord::RecordInvalid)
+  end
+
+  it 'does not allow merges between repositories' do
+    branch_in_different_repository = create_test_branch(repository_name: 'other_repository_name')
+    expect { create_test_merge(@branches[0], branch_in_different_repository) }.to raise_exception(ActiveRecord::RecordInvalid)
+  end
+
+  context 'with branches from multiple users' do
+    before do
+      @other_branches = create_test_branches(author_name: DIFFERENT_NAME, count: 2)
+      @merge_1 = create_test_merge(@branches[0], @branches[1])
+      @merge_2 = create_test_merge(@other_branches[0], @other_branches[1])
+    end
+
+    it 'can be looked up by user' do
+      merges = Merge.by_target_user(User.where(name: DIFFERENT_NAME).first)
+      expect(merges.size).to eq(1)
+      expect(merges[0].target_branch.author.name).to eq(DIFFERENT_NAME)
+    end
+
+    it 'can be filtered by status change date' do
+      merges = Merge.created_after(2.minutes.from_now)
+      expect(merges.size).to eq(0)
+
+      merges = Merge.created_after(2.minutes.ago)
+      expect(merges.size).to eq(2)
+    end
+  end
+
+  context 'with branches from multiple repositories' do
+    it 'returns branches from a repository' do
+      @merge_1 = create_test_merge(@branches[0], @branches[1])
+      @merge_2 = create_test_merge(
+          create_test_branch(repository_name: 'repository_b', name: 'name_a'),
+          create_test_branch(repository_name: 'repository_b', name: 'name_b'))
+
+      merges = Merge.from_repository('repository_b').all
+      expect(merges.size).to eq(1)
+      expect(merges[0].id).to eq(@merge_2.id)
+    end
+  end
+end
+

spec/spec_helper.rb

@@ -64,3 +64,7 @@ def create_test_branches(repository_name: 'repository_name', author_name: 'Autho
 def create_test_conflict(branch_a, branch_b, tested_at: Time.now, file_list: ['test/file.rb'])
   Conflict.create!(branch_a, branch_b, file_list, tested_at)
 end
+
+def create_test_merge(source_branch, target_branch)
+  Merge.create!(source_branch: source_branch, target_branch: target_branch)
+end