test: add controller and filter tests

test/test_controller.rb

@@ -0,0 +1,116 @@
+require 'minitest/autorun'
+require 'prism'
+require 'support'
+require 'tmpdir'
+require 'fileutils'
+
+class ControllerTest < Minitest::Test
+  include TestSupport
+
+  def setup
+    @views_dir = Dir.mktmpdir('prism-controller-views')
+    write_views
+    define_controller
+    define_app
+  end
+
+  def teardown
+    FileUtils.remove_entry(@views_dir)
+    %i[PostsController PostsApp].each { |name| Object.send(:remove_const, name) if Object.const_defined?(name) }
+  end
+
+  def write_views
+    FileUtils.mkdir_p(File.join(@views_dir, 'posts'))
+    FileUtils.mkdir_p(File.join(@views_dir, 'layouts'))
+    File.write(File.join(@views_dir, 'layouts', 'application.erb'), <<~ERB)
+      <!doctype html><html><body><%== content %></body></html>
+    ERB
+    File.write(File.join(@views_dir, 'posts', 'index.erb'), <<~ERB)
+      <ul><% posts.each do |title| %><%== partial('post', locals: { title: title }) %><% end %></ul>
+    ERB
+    File.write(File.join(@views_dir, 'posts', '_post.erb'), '<li><%= title %></li>')
+    File.write(File.join(@views_dir, 'posts', 'show.erb'), '<h1><%= id %></h1>')
+  end
+
+  def define_controller
+    views_dir = @views_dir
+    controller_class = Class.new(Prism::Controller) do
+      layout :application
+      views_root views_dir
+
+      before_action :set_common, only: %i[index show]
+      after_action :mark_served
+
+      def self.served_log
+        @served_log ||= []
+      end
+
+      def set_common
+        @posts = ['first post', 'second post']
+      end
+
+      def index
+        render(:index, locals: { posts: @posts })
+      end
+
+      def show
+        render(:show, layout: nil, locals: { id: params['id'] })
+      end
+
+      def create
+        halt(201, JSON.generate(created: params['title']))
+      end
+
+      def mark_served
+        self.class.served_log << action_name
+      end
+    end
+    Object.const_set(:PostsController, controller_class)
+  end
+
+  def define_app
+    app_class = Class.new(Prism::Application) do
+      get '/posts', to: 'posts#index', as: :posts
+      get '/posts/:id', to: 'posts#show', as: :post
+      post '/posts', to: 'posts#create'
+    end
+    Object.const_set(:PostsApp, app_class)
+  end
+
+  def call(method, path, **opts)
+    PostsApp.call(env_for(method, path, **opts))
+  end
+
+  def test_index_renders_with_layout_and_partials
+    _, _, body = call('GET', '/posts')
+    html = body.join
+    assert_includes html, '<!doctype html>'
+    assert_includes html, '<li>first post</li>'
+    assert_includes html, '<li>second post</li>'
+  end
+
+  def test_show_renders_action_template
+    _, _, body = call('GET', '/posts/42')
+    assert_equal '<h1>42</h1>', body.join
+  end
+
+  def test_before_action_runs_with_only_filter
+    PostsController.served_log.clear
+    call('GET', '/posts')
+    call('GET', '/posts/1')
+    call('POST', '/posts')
+    assert_equal %w[index show create], PostsController.served_log
+  end
+
+  def test_create_action_uses_halt
+    status, _, body = call('POST', '/posts', headers: { 'Content-Type' => 'application/x-www-form-urlencoded' }, body: 'title=hello')
+    assert_equal 201, status
+    assert_equal 'hello', JSON.parse(body.join)['created']
+  end
+
+  def test_named_route_url_for
+    status, _, body = call('GET', '/posts/9')
+    assert_equal 200, status
+    assert_equal PostsApp.router.path_to(:post, id: 9), '/posts/9'
+  end
+end