thoughtbot defaults with suspenders

Transcript

1. thoughtbot defaults with suspenders
   Dimiter Petrov
   

   View Slide

2. View Slide

3. Suspenders
   

   View Slide

4. Suspenders is an opinionated platform for adding functionality to a Rails app.
   It encodes thoughtbot's opinions and decisions in tooling and best practices.
   

   View Slide

5. Examples
   Project setup script
   Code linting and formatting with Standard Ruby
   Background jobs performed with Sidekiq
   N+1 query warnings with Bullet, with a custom configuration
   (and many more)
   

   View Slide

6. View Slide

7. In this talk
   Motivation for suspenders
     Current status
     Future plans
     Implementation
     Tests
   

   View Slide

8. History & future
   Previous: clone from a repository
   Current: suspenders
   executable runs an app generator which augments Rails'
   Next: development dependency with no executable, run generators on demand
   

   View Slide

9. Current usage
   1. gem install suspenders
   2. suspenders my-project
   

   View Slide

10. Goal usage
    1. rails new my-project && cd my-project
    2. echo 'gem "suspenders", group: :development' >> Gemfile && bundle
    3. rails g suspenders:ci
    4. Repeat with other generators as needed.
    

    View Slide

11. Implementation
    

    View Slide

12. App generator
    module Suspenders
    class AppGenerator < Rails::Generators::AppGenerator
    # overrides and extensions
    end
    end
    # bin/suspenders
    Suspenders::AppGenerator.start
    

    View Slide

13. class_option :database, type: :string, aliases: "-d", default: "postgresql",
    desc: "Configure for selected database (options: #{DATABASES.join("/")})"
    

    View Slide

14. def finish_template
    invoke :suspenders_customization
    super
    end
    def suspenders_customization
    invoke :customize_gemfile
    invoke :setup_development_environment
    invoke :setup_production_environment
    invoke :setup_secret_token
    invoke :configure_app
    invoke :copy_miscellaneous_files
    invoke :setup_database
    invoke :create_github_repo
    invoke :generate_default
    invoke :create_heroku_apps
    invoke :generate_deployment_default
    invoke :remove_config_comment_lines
    invoke :remove_routes_comment_lines
    invoke :run_database_migrations
    invoke :generate_views
    end
    

    View Slide

15. module Suspenders
    class AppGenerator < Rails::Generators::AppGenerator
    def setup_development_environment
    say "Setting up the development environment"
    # ...
    build :raise_on_delivery_errors
    # ...
    end
    end
    end
    module Suspenders
    class AppBuilder < Rails::AppBuilder
    include Suspenders::Actions
    def raise_on_delivery_errors
    replace_in_file "config/environments/development.rb",
    "raise_delivery_errors = false", "raise_delivery_errors = true"
    end
    end
    end
    

    View Slide

16. Work in progress: focused generators
    module Suspenders
    class CiGenerator < Generators::Base
    def simplecov_gem
    gem "simplecov", require: false, group: [:test]
    Bundler.with_unbundled_env { run "bundle install" }
    end
    def simplecov_test_integration
    prepend_template_to_file(test_helper_file, "partials/ci_simplecov.rb")
    end
    end
    end
    

    View Slide

17. Testing generators
    

    View Slide

18. Testing new app generation
    RSpec.describe "Suspend a new project with default configuration", type: :feature do
    before(:all) do
    drop_dummy_database
    clear_tmp_directory
    run_suspenders
    setup_app_dependencies
    end
    it "uses custom Gemfile"
    it "ensures project specs pass"
    it "adds bin/setup file"
    it "makes bin/setup executable"
    it "includes the bundle:audit task"
    # ...
    end
    

    View Slide

19. Example test of generated project
    it "configures production environment to enforce SSL" do
    production_config = read_project_file %w[config environments production.rb]
    expect(production_config).to match(
    /^ +config.force_ssl = true/
    )
    end
    def read_project_file(path)
    IO.read(File.join(project_path, *path))
    end
    

    View Slide

20. Testing a single generator
    RSpec.describe Suspenders::LintGenerator, type: :generator do
    describe "invoke" do
    it "bundles the standardrb gem" do
    with_fake_app do
    invoke! Suspenders::LintGenerator
    expect("Gemfile")
    .to match_contents(/gem .standard./)
    .and have_no_syntax_error
    end
    end
    end
    end
    

    View Slide

21. Setup for single generator tests
    def with_fake_app
    EnvPath.with_prepended_env_path(fake_bundler_bin_path) do |path|
    FakeBundler.stub_unbundled_env!(self, path: path)
    execute = lambda do
    clear_tmp_directory
    create_fake_app_dir
    Dir.chdir(app_path) { yield }
    end
    if @no_silence
    execute.call
    else
    OutputStub.silence { execute.call }
    end
    end
    end
    

    View Slide

22. Testing command output
    it "adds the standardrb rake tasks to rake" do
    with_fake_app do
    invoke! Suspenders::LintGenerator
    rake_output = `rake -T`
    expect(rake_output.lines.size).to eq 3
    expect(rake_output.lines[0]).to start_with("rake standard")
    expect(rake_output.lines[1]).to start_with("rake standard:fix")
    expect(rake_output.lines[2]).to start_with("rake standard:fix_unsafely")
    end
    end
    

    View Slide

23. Undoing a generator's work
    describe "revoke" do
    it "removes the standardrb gem from Gemfile" do
    with_fake_app do
    invoke_then_revoke! Suspenders::LintGenerator
    expect("Gemfile")
    .to not_match_contents(/gem .standard./)
    .and have_no_syntax_error
    end
    end
    it "removes the standardrb rake tasks from rake" do
    with_fake_app do
    invoke_then_revoke! Suspenders::LintGenerator
    expect(`rake -T`).to be_empty
    end
    end
    end
    

    View Slide

24. In this talk
    Motivation for suspenders
    Current status
    Future plans
    Implementation
    Tests
    

    View Slide

25. Resources
    github.com/thoughtbot/suspenders
    guides.rubyonrails.org/generators.html
    Rails::Generators::AppGenerator
    source code
    api.rubyonrails.org/classes/Rails/AppBuilder.html
    github.com/rails/thor
    

    View Slide

26. @crackofdusk@ruby.social
    

    View Slide

27. View Slide

28. View Slide

29. Helvetic Ruby
    24th November 2023 in Bern
    1 day
    8 speakers
    helvetic-ruby.ch
    

    View Slide