Add model Followship

app/models/followship.rb

@@ -0,0 +1,9 @@
+class Followship < ApplicationRecord
+  belongs_to :subject_profile, class_name: 'Profile'
+
+  belongs_to :object_profile, class_name: 'Profile'
+
+  validates :object_profile,
+            exclusion: { in: ->(followship) { [followship.subject_profile] } },
+            uniqueness: { scope: :subject_profile }
+end

db/migrate/20210310102531_create_followships.rb

@@ -0,0 +1,15 @@
+class CreateFollowships < ActiveRecord::Migration[6.1]
+  def change
+    create_table :followships do |t|
+      t.timestamps
+      t.references :subject_profile,
+                   null: false,
+                   foreign_key: { to_table: :profiles }
+      t.references :object_profile,
+                   null: false,
+                   foreign_key: { to_table: :profiles }
+
+      t.index %i[subject_profile_id object_profile_id], unique: true
+    end
+  end
+end

db/schema.rb

@@ -10,7 +10,17 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2021_03_10_092955) do
+ActiveRecord::Schema.define(version: 2021_03_10_102531) do
+
+  create_table "followships", force: :cascade do |t|
+    t.datetime "created_at", precision: 6, null: false
+    t.datetime "updated_at", precision: 6, null: false
+    t.integer "subject_profile_id", null: false
+    t.integer "object_profile_id", null: false
+    t.index ["object_profile_id"], name: "index_followships_on_object_profile_id"
+    t.index ["subject_profile_id", "object_profile_id"], name: "index_followships_on_subject_profile_id_and_object_profile_id", unique: true
+    t.index ["subject_profile_id"], name: "index_followships_on_subject_profile_id"
+  end
 
   create_table "posts", force: :cascade do |t|
     t.datetime "created_at", precision: 6, null: false
@@ -29,5 +39,7 @@ ActiveRecord::Schema.define(version: 2021_03_10_092955) do
     t.string "description"
   end
 
+  add_foreign_key "followships", "profiles", column: "object_profile_id"
+  add_foreign_key "followships", "profiles", column: "subject_profile_id"
   add_foreign_key "posts", "profiles"
 end

test/fixtures/followships.yml

@@ -0,0 +1,9 @@
+# Read about fixtures at https://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html
+
+one:
+  subject_profile: one
+  object_profile: two
+
+two:
+  subject_profile: two
+  object_profile: one

test/models/followship_test.rb

@@ -0,0 +1,7 @@
+require "test_helper"
+
+class FollowshipTest < ActiveSupport::TestCase
+  # test "the truth" do
+  #   assert true
+  # end
+end