Introduce suspenders:advisories generator

Uses the [bundler-audit][] gem to update the local security database and
show any relevant issues with the app's dependencies. This generator is
only responsible for installing the gem and adding the Rake task.

The [original implementation][] was written in 2014, and is no longer
relevant. This is because the gem ships [with a Rake task][] that can be
set as the default task, which will be addressed in #1144

Also exposes `backup_file` and `restore_file` test helpers into the
public API.

[bundler-audit]: https://github.com/rubysec/bundler-audit
[original implementation]: e23157e
[with a Rake task]: https://github.com/rubysec/bundler-audit#rake-tasks

NEWS.md

@@ -4,6 +4,7 @@ Unreleased
 * Introduce `suspenders:accessibility` generator
 * Introduce `suspenders:inline_svg` generator
 * Introduce `suspenders:factories` generator
+* Introduce `suspenders:advisories` generator
 
 20230113.0 (January, 13, 2023)
 

README.md

@@ -30,6 +30,18 @@ Installs [capybara_accessibility_audit] and [capybara_accessible_selectors]
   [capybara_accessibility_audit]: https://github.com/thoughtbot/capybara_accessibility_audit
   [capybara_accessible_selectors]: https://github.com/citizensadvice/capybara_accessible_selectors
 
+### Advisories
+
+Show security advisories during development.
+
+Uses the [bundler-audit][] gem to update the local security database and
+show any relevant issues with the app's dependencies. This generator is
+only responsible for installing the gem and adding the Rake task.
+
+`bin/rails g suspenders:advisories`
+
+  [bundler-audit]: https://github.com/rubysec/bundler-audit
+
 ### Factories
 
 Build test data with clarity and ease.

lib/generators/suspenders/advisories_generator.rb

@@ -0,0 +1,27 @@
+module Suspenders
+  module Generators
+    class AdvisoriesGenerator < Rails::Generators::Base
+      source_root File.expand_path("../../templates/advisories", __FILE__)
+      desc(<<~TEXT)
+        Show security advisories during development.
+
+        Uses the `bundler-audit` gem to update the local security database and
+        show any relevant issues with the app's dependencies via a Rake task.
+      TEXT
+
+      def add_bundler_audit
+        gem_group :development, :test do
+          gem "bundler-audit", ">= 0.7.0", require: false
+        end
+        Bundler.with_unbundled_env { run "bundle install" }
+      end
+
+      def modify_rakefile
+        insert_into_file "Rakefile", "\nrequire \"bundler/audit/task\"",
+          after: 'require_relative "config/application"'
+        insert_into_file "Rakefile", "\nBundler::Audit::Task.new",
+          after: 'require "bundler/audit/task"'
+      end
+    end
+  end
+end

test/generators/suspenders/advisories_generator_test.rb

@@ -0,0 +1,81 @@
+require "test_helper"
+require "generators/suspenders/advisories_generator"
+
+module Suspenders
+  module Generators
+    class AdvisoriesGeneratorTest < Rails::Generators::TestCase
+      include Suspenders::TestHelpers
+
+      tests Suspenders::Generators::AdvisoriesGenerator
+      destination Rails.root
+      setup :prepare_destination
+      teardown :restore_destination
+
+      test "adds gems to Gemfile" do
+        expected_output = <<~RUBY
+          group :development, :test do
+            gem "bundler-audit", ">= 0.7.0", require: false
+          end
+        RUBY
+
+        run_generator
+
+        assert_file app_root("Gemfile") do |file|
+          assert_match(expected_output, file)
+        end
+      end
+
+      test "installs gems with Bundler" do
+        output = run_generator
+
+        assert_match(/bundle install/, output)
+      end
+
+      test "generator has a description" do
+        description = <<~TEXT
+          Show security advisories during development.
+
+          Uses the `bundler-audit` gem to update the local security database and
+          show any relevant issues with the app's dependencies via a Rake task.
+        TEXT
+
+        assert_equal description, Suspenders::Generators::AdvisoriesGenerator.desc
+      end
+
+      test "modifies Rakefile" do
+        touch "Rakefile"
+        content = <<~TEXT
+          require_relative "config/application"
+
+          Rails.application.load_tasks
+        TEXT
+        File.open(app_root("Rakefile"), "w") { _1.write content }
+        expected_rakefile = <<~TEXT
+          require_relative "config/application"
+          require "bundler/audit/task"
+          Bundler::Audit::Task.new
+
+          Rails.application.load_tasks
+        TEXT
+
+        run_generator
+
+        assert_file app_root("Rakefile") do |file|
+          assert_equal expected_rakefile, file
+        end
+      end
+
+      private
+
+      def prepare_destination
+        touch "Gemfile"
+        backup_file "Rakefile"
+      end
+
+      def restore_destination
+        remove_file_if_exists "Gemfile"
+        restore_file "Rakefile"
+      end
+    end
+  end
+end

test/test_helper.rb

@@ -68,8 +68,6 @@ class Application < Rails::Application
     restore_file "config/application.rb"
   end
 
-  private
-
   def backup_file(file)
     FileUtils.mv app_root(file), app_root("#{file}.bak")
     touch file