Simple tests for relationships, following and unfollowing added.

app/models/relationship.rb

@@ -1,2 +1,6 @@
 class Relationship < ActiveRecord::Base
+  belongs_to :follower, class_name: "User"
+  belongs_to :followed, class_name: "User"
+  validates :follower_id, presence: true
+  validates :followed_id, presence: true
 end

app/models/user.rb

@@ -1,5 +1,9 @@
 class User < ActiveRecord::Base
 	has_many :microposts, dependent: :destroy
+	has_many :active_relationships, class_name: "Relationship",
+																	foreign_key: "follower_id",
+																	dependent: :destroy
+	has_many :following, through: :active_relationships, source: :followed
 	attr_accessor :remember_token, :activation_token, :reset_token
 	before_save   :downcase_email
 	before_create :create_activation_digest
@@ -76,6 +80,21 @@ def feed
 		Micropost.where("user_id = ?", id)
 	end
 
+	# Follows a user.
+	def follow(other_user)
+		active_relationships.create(followed_id: other_user.id)
+	end
+
+	# Unfollows a user.
+	def unfollow(other_user)
+		active_relationships.find_by(followed_id: other_user.id).destroy
+	end
+
+	# Returns true if the current user is following the other user.
+	def following?(other_user)
+		following.include?(other_user)
+	end
+
 	private
 
 	# Converts email to all lower case.

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: 20150817184927) do
+ActiveRecord::Schema.define(version: 20150903200654) do
 
   create_table "microposts", force: :cascade do |t|
     t.text     "content"
@@ -24,6 +24,17 @@
   add_index "microposts", ["user_id", "created_at"], name: "index_microposts_on_user_id_and_created_at"
   add_index "microposts", ["user_id"], name: "index_microposts_on_user_id"
 
+  create_table "relationships", force: :cascade do |t|
+    t.integer  "follower_id"
+    t.integer  "followed_id"
+    t.datetime "created_at",  null: false
+    t.datetime "updated_at",  null: false
+  end
+
+  add_index "relationships", ["followed_id"], name: "index_relationships_on_followed_id"
+  add_index "relationships", ["follower_id", "followed_id"], name: "index_relationships_on_follower_id_and_followed_id", unique: true
+  add_index "relationships", ["follower_id"], name: "index_relationships_on_follower_id"
+
   create_table "users", force: :cascade do |t|
     t.string   "name"
     t.string   "email"

test/fixtures/relationships.yml

@@ -1,9 +1,2 @@
-# Read about fixtures at http://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html
 
-one:
-  follower_id: 1
-  followed_id: 1
 
-two:
-  follower_id: 1
-  followed_id: 1

test/models/relationship_test.rb

@@ -1,7 +1,22 @@
 require 'test_helper'
 
 class RelationshipTest < ActiveSupport::TestCase
-  # test "the truth" do
-  #   assert true
-  # end
+
+  def setup
+    @relationship = Relationship.new(follower_id: 1, followed_id: 2)
+  end
+
+  test "should be valid" do
+    assert @relationship.valid?
+  end
+
+  test "should require a follower_id" do
+    @relationship.follower_id = nil
+    assert @relationship.invalid?
+  end
+
+  test "should require a followed_id" do
+    @relationship.followed_id = nil
+    assert @relationship.invalid?
+  end
 end

test/models/user_test.rb

@@ -84,4 +84,14 @@ def setup
   		@user.destroy
   	end
   end
+
+  test "should follow and unfollow a user" do
+    testuser = users(:testuser)
+    archer = users(:archer)
+    assert_not testuser.following?(archer)
+    testuser.follow(archer)
+    assert testuser.following?(archer)
+    testuser.unfollow(archer)
+    assert_not testuser.following?(archer)
+  end
 end