Add uniq index for Repository and Team in TeamRepositories

app/models/team_repository.rb

@@ -7,4 +7,5 @@ class TeamRepository < ApplicationRecord
   belongs_to :repository
 
   validates :permission_level, presence: true
+  validates :repository, uniqueness: { scope: :team_id }
 end

db/migrate/20190715150326_add_unique_index_to_team_repositories.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class AddUniqueIndexToTeamRepositories < ActiveRecord::Migration[5.2]
+  def change
+    add_index :team_repositories, %i(team_id repository_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_07_11_125513) do
+ActiveRecord::Schema.define(version: 2019_07_15_150326) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "btree_gist"
@@ -725,6 +725,7 @@ ActiveRecord::Schema.define(version: 2019_07_11_125513) do
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.index ["repository_id"], name: "index_team_repositories_on_repository_id"
+    t.index ["team_id", "repository_id"], name: "index_team_repositories_on_team_id_and_repository_id", unique: true
     t.index ["team_id"], name: "index_team_repositories_on_team_id"
   end
 

spec/models/team_repository_spec.rb

@@ -13,6 +13,9 @@ describe TeamRepository, type: :model do
     describe '#permission_level' do
       it { is_expected.to validate_presence_of(:permission_level) }
     end
+    describe '#repository' do
+      it { expect(team_repository).to validate_uniqueness_of(:repository).scoped_to(:team_id) }
+    end
   end
 
   describe 'Associations' do