bismuth1991/zing-lite-rails-api

Rails JSON API

A standalone Rails/PostgreSQL back-end server which:

• Serves JSON music data to my front-end music web application Zing Lite - live - github
• Has a full User Authentication cycle with proper secured password (via BCrypt); selective CORS management; Rails' session token stored in database, and CSRF Token served to front-end

Features:

Test-driven-development, models and controller tests with RSpec:

RSpec.describe User, type: :model do
  describe 'password encryption' do
    it 'does not save passwords to the database' do
      User.create!(username: 'chuck_norris', password: 'password')
      user = User.find_by_username('chuck_norris')
      expect(user.password).not_to be('password')
    end

    it 'encrypts the password using BCrypt' do
      expect(BCrypt::Password).to receive(:create)
      User.new(username: 'chuck_norris', password: 'password')
    end
  end
# ...
end

RSpec.describe 'Songs API', type: :request do
  describe 'GET #index' do
    before(:each) do 
      # ...
      get '/api/songs/'
    end

    it 'responses with status code of 200' do
      expect(response).to have_http_status(200)
    end

    it 'fetches songs with corresponding artists and albums' do 
      expect(response.body).to match_response_schema('all_songs')
    end
    # ...
  end
end

Avoid N + 1 queries while fectching complicated JSON data for front-end

// Required JSON data

{
  "type": "object",
  "required": [
    "songs",
    "artists",
    "albums"
  ],
  "properties": {
    "songs": { "type": "object" },
    "artists": { "type": "object" },
    "albums": { "type": "object" }
  }
}

{
  "type": "object",
  "required": [
    "id",
    "title",
    "url",
    "artistId",
    "albumId"
  ],
  "properties": {
    "id": { "type": "integer" },
    "title": { "type": "string" },
    "url": { "type": "string" },
    "artistId": { "type": "integer" },
    "albumId": { "type": "integer" }
  }
}

{
  "type": "object",
  "required": [
    "id",
    "name",
    "avatarUrl"
  ],
  "properties": {
    "id": { "type": "integer" },
    "name": { "type": "string" },
    "avatarUrl": { "type": "string" }
  }
}

{
  "type": "object",
  "required": [
    "id",
    "name",
    "coverImageUrl"
  ],
  "properties": {
    "id": { "type": "integer" },
    "name": { "type": "string" },
    "coverImageUrl": { "type": "string" }
  }
}

# ActiveRecords' query

class Api::SongsController < ApplicationController
  def index 
    @songs = Song.includes(:artist, :album).limit(20).offset(params[:off_set]).order(:id)

    artist_set = Set.new
    album_set = Set.new

    @songs.each do |song|
      artist_set.add(song.artist)
      album_set.add(song.album)
    end

    @artists = artist_set.to_a
    @albums = album_set.to_a

    render :index
  end
end

Normalized schemas:

users

column name	data type	details
id	integer	primary key, not null
email	string	not null, unique, indexed
password_digest	string	not null
session_token	string	not null, unique, indexed
created_at	datetime	not null
updated_at	datetime	not null

songs

column name	data type	details
id	integer	primary key, not null
title	string	not null, indexed
url	string	not null
album_id	integer	indexed, foreign key
artist_id	integer	indexed, foreign key
created_at	datetime	not null
updated_at	datetime	not null

artists

column name	data type	details
id	integer	primary key, not null
name	string	not null, indexed
avatar_url	string	not null
created_at	datetime	not null
updated_at	datetime	not null

albums

column name	data type	details
id	integer	primary key, not null
name	string	not null, indexed
cover_image_url	string	not null
created_at	datetime	not null
updated_at	datetime	not null

playlists

column name	data type	details
id	integer	primary key, not null
name	string	not null, unique, indexed
created_at	datetime	not null
updated_at	datetime	not null

song_playlists

column name	data type	details
id	integer	primary key, not null
song_id	integer	foreign key, not null, indexed
playlist_id	integer	foreign key, not null, indexed
created_at	datetime	not null
updated_at	datetime	not null

• indexed on [:song_id, :playlist_id], unique: true