wip: test generators

.rubocop.yml

@@ -3,6 +3,7 @@ AllCops:
   DisabledByDefault: true
   Exclude:
     - lib/generators/**/templates/**/*
+    - tmp/**/*
 
 Gemspec/OrderedDependencies:
   Enabled: true

spec/generators/decorator_generator_spec.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+RSpec.describe "decorator", type: :generator do
+  before { with_app { generate("dekorator:install") } }
+
+  it "generates a Decorator file for a simple Object" do
+    generate("decorator User")
+
+    expect("app/decorators/user_decorator.rb").to match_contents(%r{UserDecorator})
+  end
+
+  it "generates a Decorator file for a namespaced Object" do
+    generate("decorator Product::Attribute")
+
+    expect("app/decorators/product/attribute_decorator.rb").to match_contents(%r{Product::AttributeDecorator})
+  end
+end

spec/generators/dekorator_install_generator_spec.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+RSpec.describe "dekorator:install", type: :generator do
+  it "creates ApplicationDecorator file" do
+    with_app { generate("dekorator:install") }
+
+    expect("app/decorators/application_decorator.rb").to match_contents(%r{ApplicationDecorator})
+  end
+end

spec/lib/dekorator/decorators_helper.rb

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+require "active_support/core_ext/module/delegation"
+require "dekorator/decorators_helper"
+
+require File.expand_path("../fixtures/models.rb", __dir__)
+require File.expand_path("../fixtures/decorators.rb", __dir__)
+
+RSpec.describe DecoratorsHelper do
+  let(:comment) { Comment.new(author_name: "john.doe", body: "comment message") }
+  let(:post)    { Post.new(name: "post title", body: "a" * 200, comments: [comment]) }
+
+  describe "#decorate" do
+    context "with object" do
+      it { expect(described_class.decorate(post)).to be_a(PostDecorator) }
+      it { expect(described_class.decorate(post)).to be_a(PostDecorator) }
+    end
+
+    context "with enumerable" do
+      it { expect(described_class.decorate([post, post, post])).to all(be_a(PostDecorator)) }
+      it { expect(described_class.decorate([post, post, post])).to all(be_a(PostDecorator)) }
+      it { expect(described_class.decorate([post, post, post])).to be_a(Enumerable) }
+    end
+  end
+end

spec/lib/dekorator_base_spec.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
-#
+
 require File.expand_path("../fixtures/models.rb", __dir__)
 require File.expand_path("../fixtures/decorators.rb", __dir__)
 

spec/spec_helper.rb

@@ -4,8 +4,12 @@
 SimpleCov.start
 
 require "bundler/setup"
+Bundler.require(:default, :test)
+
 require "dekorator"
 
+Dir["./spec/support/**/*.rb"].each { |file| require file }
+
 RSpec.configure do |config|
   # Enable flags like --only-failures and --next-failure
   config.example_status_persistence_file_path = ".rspec_status"

spec/support/generators.rb

@@ -0,0 +1,135 @@
+# frozen_string_literal: true
+
+module GeneratorTestHelpers
+  APP_NAME = "dummy_app"
+
+  def remove_project_directory
+    FileUtils.rm_rf(project_path)
+  end
+
+  def create_tmp_directory
+    FileUtils.mkdir_p(tmp_path)
+  end
+
+  def remove_decorators_directory
+    FileUtils.rm_rf(decorators_path)
+    FileUtils.rm_rf(decorators_spec_path)
+    FileUtils.rm_rf(decorators_test_path)
+  end
+
+  def with_app
+    remove_project_directory
+    rails_new
+
+    yield
+  end
+
+  def rails_new
+    run_in_tmp do
+      debug `#{system_rails_bin} new #{APP_NAME} --skip-webpack-install`
+
+      Dir.chdir(APP_NAME) do
+        File.open("Gemfile", "a") do |file|
+          file.puts %{gem "dekorator", path: #{root_path.inspect}}
+        end
+      end
+    end
+  end
+
+  def generate(generator)
+    run_in_project do
+      debug `bin/spring stop`
+      debug `#{project_rails_bin} generate #{generator}`
+    end
+  end
+
+  def destroy(generator)
+    run_in_project do
+      `bin/spring stop`
+      `#{project_rails_bin} destroy #{generator}`
+    end
+  end
+
+  def project_path
+    @project_path ||= Pathname.new("#{tmp_path}/#{APP_NAME}")
+  end
+
+  def decorators_path
+    @decorators_path ||= Pathname.new("#{tmp_path}/#{APP_NAME}/app/decorators")
+  end
+
+  def decorators_spec_path
+    @decorators_path ||= Pathname.new("#{tmp_path}/#{APP_NAME}/spec/decorators")
+  end
+
+  def decorators_test_path
+    @decorators_path ||= Pathname.new("#{tmp_path}/#{APP_NAME}/test/decorators")
+  end
+
+  private
+
+  def tmp_path
+    @tmp_path ||= Pathname.new("#{root_path}/tmp")
+  end
+
+  def system_rails_bin
+    "rails"
+  end
+
+  def project_rails_bin
+    "bin/rails"
+  end
+
+  def root_path
+    File.expand_path('../../../', __FILE__)
+  end
+
+  def with_env(name, new_value)
+    had_key = ENV.has_key?(name)
+    prior = ENV[name]
+    ENV[name] = new_value.to_s
+
+    yield
+
+  ensure
+    ENV.delete(name)
+
+    if had_key
+      ENV[name] = prior
+    end
+  end
+
+  def run_in_tmp
+    create_tmp_directory
+
+    Dir.chdir(tmp_path) do
+      Bundler.with_clean_env do
+        yield
+      end
+    end
+  end
+
+  def run_in_project
+    Dir.chdir(project_path) do
+      Bundler.with_clean_env do
+        yield
+      end
+    end
+  end
+
+  def debug(output)
+    if ENV["DEBUG"]
+      warn output
+    end
+
+    output
+  end
+end
+
+RSpec.configure do |config|
+  config.include GeneratorTestHelpers
+
+  config.before(:each, type: :generator) do
+    remove_project_directory
+  end
+end

spec/support/match_contents_matcher.rb

@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+RSpec::Matchers.define :match_contents do |regexp|
+  match do |filename|
+    contents = IO.read(File.join(project_path, filename))
+    contents =~ regexp
+  end
+end