Test dartsass:install command

This adds test coverage for the `dartsass:install` command.  The command
is tested against a freshly generated Rails app using the version of
Rails that is currently loaded.  Thus the installer can be tested with
different versions of Rails in CI.

test/installer_test.rb

@@ -0,0 +1,71 @@
+require "test_helper"
+
+class InstallerTest < ActiveSupport::TestCase
+ include RailsAppHelpers
+
+ test "installer" do
+ with_new_rails_app do
+ out, _err = run_command("bin/rails", "dartsass:install")
+
+ assert_match "<DONE>", out
+ assert_equal 0, File.size("app/assets/builds/.keep")
+ assert_match "/app/assets/builds/*\n!/app/assets/builds/.keep", File.read(".gitignore")
+ assert_equal File.read("#{__dir__}/../lib/install/application.scss"), File.read("app/assets/stylesheets/application.scss")
+ assert_equal File.read("#{__dir__}/../lib/install/Procfile.dev"), File.read("Procfile.dev")
+ assert_equal File.read("#{__dir__}/../lib/install/dev"), File.read("bin/dev")
+ assert_equal 0700, File.stat("bin/dev").mode & 0700
+
+ if sprockets?
+ assert_match "//= link_tree ../builds", File.read("app/assets/config/manifest.js")
+ assert_no_match "//= link_directory ../stylesheets .css", File.read("app/assets/config/manifest.js")
+ end
+ end
+ end
+
+ test "installer with missing .gitignore" do
+ with_new_rails_app do
+ FileUtils.rm(".gitignore")
+ out, _err = run_command("bin/rails", "dartsass:install")
+
+ assert_match "<DONE>", out
+ assert_not File.exist?(".gitignore")
+ end
+ end
+
+ test "installer with pre-existing application.scss" do
+ with_new_rails_app do
+ File.write("app/assets/stylesheets/application.scss", "// pre-existing")
+ out, _err = run_command("bin/rails", "dartsass:install")
+
+ assert_match "<DONE>", out
+ assert_equal "// pre-existing", File.read("app/assets/stylesheets/application.scss")
+ end
+ end
+
+ test "installer with pre-existing Procfile" do
+ with_new_rails_app do
+ File.write("Procfile.dev", "pre: existing\n")
+ out, _err = run_command("bin/rails", "dartsass:install")
+
+ assert_match "<DONE>", out
+ assert_equal "pre: existing\ncss: bin/rails dartsass:watch\n", File.read("Procfile.dev")
+ end
+ end
+
+ private
+ def with_new_rails_app(&block)
+ super do
+ # Override `dartsass:build` to check that installation completed and to reduce test run time.
+ File.write("Rakefile", <<~RAKEFILE, mode: "a+")
+ Rake::Task["dartsass:build"].clear
+ namespace :dartsass do
+ task build: :environment do
+ puts "<DONE>"
+ end
+ end
+ RAKEFILE
+
+ block.call
+ end
+ end
+end

test/test_helper.rb

@@ -4,3 +4,74 @@
 require "fileutils"
 require "rails"
 require "rails/test_help"
+
+module RailsAppHelpers
+ def self.included(base)
+ base.include ActiveSupport::Testing::Isolation
+ end
+
+ private
+ def sprockets?
+ Gem.loaded_specs.key?("sprockets-rails")
+ end
+
+ def propshaft?
+ Gem.loaded_specs.key?("propshaft")
+ end
+
+ def asset_pipeline_option
+ if Rails::VERSION::MAJOR > 7
+ if propshaft?
+ "--asset-pipeline=propshaft"
+ elsif sprockets?
+ "--asset-pipeline=sprockets"
+ end
+ end
+ end
+
+ def create_new_rails_app(app_dir)
+ require "rails/generators/rails/app/app_generator"
+ Rails::Generators::AppGenerator.start([app_dir, *asset_pipeline_option, "--skip-bundle", "--skip-bootsnap", "--quiet"])
+
+ Dir.chdir(app_dir) do
+ gemfile = File.read("Gemfile")
+
+ gemfile.gsub!(/^gem ["']sassc?-rails["'].*/, "") # for Rails 6.1 and 7.0
+ gemfile.gsub!(/^gem ["']dartsass-rails["'].*/, "")
+ gemfile << %(gem "dartsass-rails", path: #{File.expand_path("..", __dir__).inspect}\n)
+
+ if Rails::VERSION::PRE == "alpha"
+ gemfile.gsub!(/^gem ["']rails["'].*/, "")
+ gemfile << %(gem "rails", path: #{Gem.loaded_specs["rails"].full_gem_path.inspect}\n)
+ end
+
+ File.write("Gemfile", gemfile)
+
+ run_command("bundle", "install")
+ end
+ end
+
+ def with_new_rails_app(&block)
+ require "digest/sha1"
+ variant = [Gem.loaded_specs["rails"].full_gem_path, asset_pipeline_option]
+ app_name = "app_#{Digest::SHA1.hexdigest(variant.to_s)}"
+ cache_dir = "#{__dir__}/../tmp"
+
+ Dir.mktmpdir do |tmpdir|
+ if Dir.exist?("#{cache_dir}/#{app_name}")
+ FileUtils.cp_r("#{cache_dir}/#{app_name}", tmpdir)
+ else
+ create_new_rails_app("#{tmpdir}/#{app_name}")
+ FileUtils.cp_r("#{tmpdir}/#{app_name}", cache_dir) # Cache app for future runs.
+ end
+
+ Dir.chdir("#{tmpdir}/#{app_name}", &block)
+ end
+ end
+
+ def run_command(*command)
+ Bundler.with_unbundled_env do
+ capture_subprocess_io { system(*command, exception: true) }
+ end
+ end
+end