generator-for-devise-jwt: Implement the generator for devise-jwt

CHANGELOG.md

@@ -13,6 +13,7 @@
 * Adds Honeybadger generator. ([@mausamp][])
 * Adds Rails ERD generator. ([@mausamp][])
 * Adds Annotate Generator. ([@TheZero0-ctrl][])
+* Adds Devise JWT generator. ([@TheZero0-ctrl][])
 
 ## 0.13.0 (March 26th, 2024)
 * Adds Letter Opener generator. ([@coolprobn][])

README.md

@@ -96,6 +96,7 @@ The boring generator introduces following generators:
 - Install Honeybadger: `rails generate boring:honeybadger:install`
 - Install Rails ERD: `rails generate boring:rails_erd:install`
 - Install Annotate: `rails generate boring:annotate:install`
+- Install Devise JWT: `rails generate boring:devise:jwt:install`
 
 ## Screencasts
 

lib/generators/boring/devise/jwt/install/install_generator.rb

@@ -0,0 +1,189 @@
+# frozen_string_literal: true
+
+require 'boring_generators/generator_helper'
+
+module Boring
+  module Devise
+    module Jwt
+      class InstallGenerator < Rails::Generators::Base
+        include Rails::Generators::Migration
+        include BoringGenerators::GeneratorHelper
+
+        desc "Add devise-jwt to the application"
+        source_root File.expand_path('templates', __dir__)
+
+        class_option :model_name, type: :string, aliases: "-m",
+                     default: "User",
+                     desc: "Tell us the user model name which will be used for authentication. Defaults to User"
+        class_option :use_env_variable, type: :boolean, aliases: "-ev",
+                     desc: "Use ENV variable for devise_jwt_secret_key. By default Rails credentials will be used."
+        class_option :revocation_strategy, type: :string, aliases: "-rs",
+                     enum: %w[JTIMatcher Denylist Allowlist],
+                     default: "Denylist",
+                     desc: "Tell us the revocation strategy to be used. Defaults to Denylist"
+        class_option :expiration_time_in_days, type: :numeric, aliases: "-et",
+                      default: 15,
+                      desc: "Tell us the expiration time on days for the JWT token. Defaults to 15 days"
+
+        def self.next_migration_number(dirname)
+          next_migration_number = current_migration_number(dirname) + 1
+          ActiveRecord::Migration.next_migration_number(next_migration_number)
+        end
+
+        def verify_presence_of_devise_gem
+          return if gem_installed?("devise")
+
+          say "We couldn't find devise gem. Please configure devise gem and rerun the generator. Consider running `rails generate boring:devise:install` to set up Devise.",
+              :red
+
+          abort
+        end
+
+        def verify_presence_of_devise_initializer
+          return if File.exist?("config/initializers/devise.rb")
+
+          say "We couldn't find devise initializer. Please configure devise gem and rerun the generator. Consider running `rails generate boring:devise:install` to set up Devise.",
+              :red
+
+          abort
+        end
+
+        def verify_presence_of_devise_model
+          return if File.exist?("app/models/#{options[:model_name].underscore}.rb")
+
+          say "We couldn't find the #{options[:model_name]} model. Maybe there is a typo? Please provide the correct model name and run the generator again.", :red
+
+          abort
+        end
+
+        def add_devise_jwt_gem
+          say "Adding devise-jwt gem", :green
+          check_and_install_gem("devise-jwt")
+          bundle_install
+        end
+
+        def add_devise_jwt_config_to_devise_initializer
+          say "Adding devise-jwt configurations to a file `config/initializers/devise.rb`", :green
+
+          jwt_config = <<~RUBY
+            config.jwt do |jwt|
+              jwt.secret = #{devise_jwt_secret_key}
+              jwt.dispatch_requests = [
+                ['POST', %r{^/sign_in$}]
+              ]
+              jwt.revocation_requests = [
+                ['DELETE', %r{^/sign_out$}]
+              ]
+              jwt.expiration_time = #{options[:expiration_time_in_days]}.day.to_i
+            end
+          RUBY
+
+          inject_into_file "config/initializers/devise.rb",
+                            optimize_indentation(jwt_config, 2),
+                            before: /^end\s*\Z/m
+
+          say "❗️❗️\nValue for jwt.secret will be used from `#{devise_jwt_secret_key}`. You can change this values if they don't match with your app.\n",
+              :yellow
+        end
+
+        def configure_revocation_strategies
+          say "Configuring #{options[:revocation_strategy]} revocation strategy",
+              :green
+
+          case options[:revocation_strategy]
+          when "JTIMatcher"
+            configure_jti_matcher_strategy
+          when "Denylist"
+            configure_denylist_strategy
+          when "Allowlist"
+            configure_allowlist_strategy
+          end
+        end
+
+        private
+
+        def devise_jwt_secret_key
+          if options[:use_env_variable]
+            "ENV['DEVISE_JWT_SECRET_KEY']"
+          else
+            "Rails.application.credentials.devise_jwt_secret_key"
+          end
+        end
+
+        def configure_jti_matcher_strategy
+          @model_db_table = options[:model_name].tableize
+          @model_class = @model_db_table.camelcase
+
+          migration_template "add_jti_to_users.rb", "db/migrate/add_jti_to_#{@model_db_table}.rb"
+
+          add_devise_jwt_module(
+            strategy: "self",
+            include_content: "include Devise::JWT::RevocationStrategies::JTIMatcher"
+          )
+        end
+
+        def configure_denylist_strategy
+          Bundler.with_unbundled_env do
+            run "bundle exec rails generate model jwt_denylist --skip-migration"
+          end
+
+          migration_template "create_jwt_denylist.rb", "db/migrate/create_jwt_denylist.rb"
+
+          add_devise_jwt_module(strategy: "JwtDenylist")
+
+          jwt_denylist_content = <<~RUBY
+            include Devise::JWT::RevocationStrategies::Denylist
+            self.table_name = 'jwt_denylist'
+          RUBY
+
+          inject_into_file "app/models/jwt_denylist.rb",
+                           optimize_indentation(jwt_denylist_content, 2),
+                           after: /ApplicationRecord\n/,
+                           verbose: false
+        end
+
+        def configure_allowlist_strategy
+          @model_underscore = options[:model_name].underscore
+          Bundler.with_unbundled_env do
+            run "bundle exec rails generate model allowlisted_jwt --skip-migration"
+          end
+
+          migration_template "create_allowlisted_jwts.rb", "db/migrate/create_allowlisted_jwts.rb"
+
+          add_devise_jwt_module(
+            strategy: "self",
+            include_content: "include Devise::JWT::RevocationStrategies::Allowlist"
+          )
+        end
+
+        def add_devise_jwt_module(strategy:, include_content: nil)
+          model_name = options[:model_name].underscore
+          model_content = File.read("app/models/#{model_name}.rb")
+          devise_module_pattern = /devise\s*(?:(?:(?::\w+)|(?:\w+:\s*\w+))(?:(?:,\s*:\w+)|(?:,\s*\w+:\s*\w+))*)/
+
+          if model_content.match?(devise_module_pattern)
+            inject_into_file "app/models/#{model_name}.rb",
+                              ", :jwt_authenticatable, jwt_revocation_strategy: #{strategy}",
+                              after: devise_module_pattern
+          else
+            inject_into_file "app/models/#{model_name}.rb",
+                             optimize_indentation(
+                               "devise :jwt_authenticatable, jwt_revocation_strategy: #{strategy}",
+                               2
+                             ),
+                             after: /ApplicationRecord\n/
+            say "Successfully added the devise-jwt module to #{model_name} model. However, it looks like the devise module is missing from the #{model_name} model. Please configure the devise module to ensure everything functions correctly.",
+                :yellow
+          end
+
+          if include_content
+            inject_into_file "app/models/#{model_name}.rb",
+                             optimize_indentation(include_content, 2),
+                             after: /ApplicationRecord\n/,
+                             verbose: false
+          end
+        end
+      end
+    end
+  end
+end

lib/generators/boring/devise/jwt/install/templates/add_jti_to_users.rb.tt

@@ -0,0 +1,6 @@
+class AddJtiTo<%= @model_class %> < ActiveRecord::Migration[<%= ActiveRecord::Migration.current_version %>]
+  def change
+    add_column :<%= @model_db_table %>, :jti, :string, null: false
+    add_index :<%= @model_db_table %>, :jti, unique: true
+  end
+end

lib/generators/boring/devise/jwt/install/templates/create_allowlisted_jwts.rb.tt

@@ -0,0 +1,15 @@
+class CreateAllowlistedJwts < ActiveRecord::Migration[<%= ActiveRecord::Migration.current_version %>] 
+  def change
+    create_table :allowlisted_jwts do |t|
+      t.string :jti, null: false
+      t.string :aud
+      # If you want to leverage the `aud` claim, add to it a `NOT NULL` constraint:
+      # t.string :aud, null: false
+      t.datetime :exp, null: false
+      t.references :<%= @model_underscore %>, foreign_key: { on_delete: :cascade }, null: false
+
+      t.timestamps
+    end
+    add_index :allowlisted_jwts, :jti
+  end
+end

lib/generators/boring/devise/jwt/install/templates/create_jwt_denylist.rb.tt

@@ -0,0 +1,11 @@
+class CreateJwtDenylist < ActiveRecord::Migration[<%= ActiveRecord::Migration.current_version %>]
+  def change
+    create_table :jwt_denylist do |t|
+      t.string :jti, null: false
+      t.datetime :exp, null: false
+
+      t.timestamps
+    end
+    add_index :jwt_denylist, :jti
+  end
+end

test/generators/devise/devise_jwt_install_generator_test.rb

@@ -0,0 +1,136 @@
+# frozen_string_literal: true
+
+require "test_helper"
+require "generators/boring/devise/jwt/install/install_generator"
+
+class DeviseInstallGeneratorTest < Rails::Generators::TestCase
+  tests Boring::Devise::Jwt::InstallGenerator
+  setup :build_app
+  teardown :teardown_app
+
+  include GeneratorHelper
+  include ActiveSupport::Testing::Isolation
+
+  def destination_root
+    app_path
+  end
+
+  def test_should_exit_if_devise_is_not_installed
+    assert_raises SystemExit do
+      quietly { generator.verify_presence_of_devise_gem }
+    end
+  end
+
+  def test_should_exit_if_devise_initializer_is_not_present
+    assert_raises SystemExit do
+      quietly { generator.verify_presence_of_devise_initializer }
+    end
+  end
+
+  def test_should_exit_if_devise_model_is_not_present
+    assert_raises SystemExit do
+      quietly { generator.verify_presence_of_devise_model }
+    end
+  end
+
+  def test_should_configure_devise_jwt
+    Dir.chdir(app_path) do
+      setup_devise
+      quietly { run_generator }
+      assert_gem "devise-jwt"
+      assert_file "config/initializers/devise.rb" do |content|
+        assert_match(/config.jwt do |jwt|/, content)
+        assert_match(/jwt.secret = Rails.application.credentials.devise_jwt_secret/, content)
+        assert_match(/jwt\.dispatch_requests\s*=\s*\[\s*/, content)
+        assert_match(/jwt\.revocation_requests\s*=\s*\[\s*/, content)
+        assert_match(/jwt\.expiration_time\s*=\s*/, content)
+      end
+      assert_migration "db/migrate/create_jwt_denylist.rb"
+      assert_file "app/models/user.rb" do |content|
+        assert_match(
+          /devise\s*(?:(?:(?::\w+)|(?:\w+:\s*\w+))(?:(?:,\s*:\w+)|(?:,\s*\w+:\s*\w+))*)*(?:,\s*:jwt_authenticatable, jwt_revocation_strategy: JwtDenylist)/,
+          content
+        )
+      end
+
+      assert_file "app/models/jwt_denylist.rb" do |content|
+        assert_match(/include Devise::JWT::RevocationStrategies::Denylist/, content)
+        assert_match(/self\.table_name = 'jwt_denylist'/, content)
+      end
+    end
+  end
+
+  def test_should_use_env_variable_for_devise_jwt_secret
+    Dir.chdir(app_path) do
+      setup_devise
+      quietly { run_generator [destination_root, "--use_env_variable"] }
+      assert_file "config/initializers/devise.rb" do |content|
+        assert_match(/jwt\.secret\s*=\s*ENV\['DEVISE_JWT_SECRET_KEY'\]/, content)
+      end
+    end
+  end
+
+  def test_should_configure_jti_matcher_revocation_strategy
+    Dir.chdir(app_path) do
+      setup_devise
+      quietly { run_generator [destination_root, "--revocation_strategy=JTIMatcher"] }
+      assert_migration "db/migrate/add_jti_to_users.rb"
+      assert_file "app/models/user.rb" do |content|
+        assert_match(/include Devise::JWT::RevocationStrategies::JTIMatcher/, content)
+        assert_match(
+          /devise\s*(?:(?:(?::\w+)|(?:\w+:\s*\w+))(?:(?:,\s*:\w+)|(?:,\s*\w+:\s*\w+))*)*(?:,\s*:jwt_authenticatable, jwt_revocation_strategy: self)/,
+          content
+        )
+      end
+    end
+  end
+
+  def test_should_configure_allowlist_revocation_strategy
+    Dir.chdir(app_path) do
+      setup_devise
+      quietly { run_generator [destination_root, "--revocation_strategy=Allowlist"] }
+      assert_migration "db/migrate/create_allowlisted_jwts.rb"
+      assert_file "app/models/user.rb" do |content|
+        assert_match(/include Devise::JWT::RevocationStrategies::Allowlist/, content)
+        assert_match(
+          /devise\s*(?:(?:(?::\w+)|(?:\w+:\s*\w+))(?:(?:,\s*:\w+)|(?:,\s*\w+:\s*\w+))*)*(?:,\s*:jwt_authenticatable, jwt_revocation_strategy: self)/,
+          content
+        )
+      end
+      assert_file "app/models/allowlisted_jwt.rb"
+    end
+  end
+
+  private
+
+  def setup_devise(model_name: "User")
+    Bundler.with_unbundled_env do
+      `bundle add devise`
+    end
+
+    create_devise_initializer
+    create_devise_model(model_name)
+  end
+
+  def create_devise_initializer
+    FileUtils.mkdir_p("#{app_path}/config/initializers")
+    content = <<~RUBY
+      Devise.setup do |config|
+      end
+    RUBY
+
+    File.write("#{app_path}/config/initializers/devise.rb", content)
+  end
+
+  def create_devise_model(model_name)
+    FileUtils.mkdir_p("#{app_path}/app/models")
+    content = <<~RUBY
+      class #{model_name} < ApplicationRecord
+         devise :database_authenticatable, :registerable,
+                :recoverable, :rememberable, :validatable
+      end
+    RUBY
+
+    File.write("#{app_path}/app/models/#{model_name.underscore}.rb", content)
+  end
+end