Add generator test (#300)

* Add base rails dummy app for test

* Add test for bin/setup and peer dependencies

* Add e2e test after installation

---------

Co-authored-by: Judah Meek <judah.meek@gmail.com>

.github/workflows/generator.yml

@@ -0,0 +1,37 @@
+name: Generator specs
+
+on: [push]
+
+jobs:
+  test:
+    name: Generator specs
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest]
+        ruby: ['2.6', '2.7', '3.0']
+        gemfile:
+          - gemfiles/Gemfile-rails.6.0.x
+          - gemfiles/Gemfile-rails.6.1.x
+          - gemfiles/Gemfile-rails.7.0.x
+          # Uncomment the following line only to ensure compatibility with the
+          # upcomming Rails versions, maybe before a release.
+          #- gemfiles/Gemfile-rails-edge
+        exclude:
+          - ruby: 2.6
+            os: ubuntu-latest
+            gemfile: gemfiles/Gemfile-rails.7.0.x
+          - ruby: 2.6
+            os: ubuntu-latest
+            gemfile: gemfiles/Gemfile-rails-edge
+    env:
+      BUNDLE_GEMFILE: ${{ matrix.gemfile }}
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby }}
+      - name: Install dependencies
+        run: bundle install
+      - run: bundle exec rake run_spec:generator

CONTRIBUTING.md

@@ -78,15 +78,17 @@ For this, you need `yalc` to be installed on your local machine
 bundle exec rake run_spec:dummy
 ```
 
-## Testing the generator
-If you change the generator, check that install instructions work.
+#### 4.6 Testing the installer
+To ensure that your installer works as expected, either you can run `bundle exec rake run_spec:install`, or take the following manual testing steps:
 
-1. Update the Gemfile so that gem "shakapacker" has a line like this, pointing to your install of Shakapacker
+1. Update the `Gemfile` so that gem `shakapacker` has a line like this, pointing to your developing Shakapacker:
    ```ruby
-   gem 'shakapacker', path: "~/shakacode/forks/shakapacker"
+   gem 'shakapacker', path: "relative_or_absolute_path_to_the_gem"
    ```
-2. `bundle`
-3. Run the generator to confirm that you got the right changes. 
+2. Run `bundle install` to install the updated gem.
+3. Run `bundle exec rails shakapacker:install` to confirm that you got the right changes.
+
+ **Note:** Ensure that you use bundle exec otherwise the installed shakapacker gem will run and not the one you are working on.
 
 ## Find existing issues
 You may look at the issues list to find existing known issues to be addressed. In this, we recommend looking at closed issues, particularly with the "[help wanted](https://github.com/shakacode/shakapacker/issues?q=is%3Aissue+label%3A%22help+wanted%22+is%3Aclosed+)" label.

Rakefile

@@ -11,13 +11,13 @@ namespace :run_spec do
   desc "Run shakapacker specs"
   task :gem do
     puts "Running Shakapacker gem specs"
-    system("bundle exec rspec spec/shakapacker/*_spec.rb")
+    sh("bundle exec rspec spec/shakapacker/*_spec.rb")
   end
 
   desc "Run backward compatibility specs"
   task :gem_bc do
     puts "Running Shakapacker gem specs for backward compatibility"
-    system("bundle exec rspec spec/backward_compatibility_specs/*_spec_bc.rb")
+    sh("bundle exec rspec spec/backward_compatibility_specs/*_spec_bc.rb")
   end
 
   desc "Run specs in the dummy app"
@@ -35,12 +35,17 @@ namespace :run_spec do
     end
   end
 
+  desc "Run generator specs"
+  task :generator do
+    sh("bundle exec rspec spec/generator_specs/*_spec.rb")
+  end
+
   desc "Run all specs"
-  task all_specs: %i[gem gem_bc dummy] do
+  task all_specs: %i[gem gem_bc dummy generator] do
     puts "Completed all RSpec tests"
   end
 end
 
 def sh_in_dir(dir, *shell_commands)
-  shell_commands.flatten.each { |shell_command| sh %(cd #{dir} && #{shell_command.strip}) }
+  Shakapacker::Utils::Misc.sh_in_dir(dir, *shell_commands)
 end

spec/generator_specs/e2e_template/files/app/controllers/home_controller.rb

@@ -0,0 +1,4 @@
+class HomeController < ApplicationController
+  def index
+  end
+end

spec/generator_specs/e2e_template/files/app/javascript/components/App.js

@@ -0,0 +1,12 @@
+import React from 'react'
+
+function App() {
+  return (
+    <div className="App">
+      <h1>App component</h1>
+      <p>Text from react component!</p>
+    </div>
+  )
+}
+
+export default App

spec/generator_specs/e2e_template/files/app/javascript/packs/application.js

@@ -0,0 +1,10 @@
+import React from 'react'
+import ReactDOM from 'react-dom/client'
+import App from '../components/App'
+
+const root = ReactDOM.createRoot(document.getElementById('root'))
+root.render(
+  <React.StrictMode>
+    <App />
+  </React.StrictMode>
+)

spec/generator_specs/e2e_template/files/app/views/home/index.html.erb

@@ -0,0 +1,2 @@
+<h1>Home#index</h1>
+<p>Find me in app/views/home/index.html.erb</p>

spec/generator_specs/e2e_template/files/app/views/layouts/application.html.erb

@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>Sh7InstallTest</title>
+    <meta name="viewport" content="width=device-width,initial-scale=1">
+    <%= csrf_meta_tags %>
+    <%= csp_meta_tag %>
+
+    <%= stylesheet_link_tag "application" %>
+    <%= javascript_pack_tag "application" %>
+  </head>
+
+  <body>
+    <%= yield %>
+    <div id="root"></div>
+  </body>
+</html>

spec/generator_specs/e2e_template/files/config/routes.rb

@@ -0,0 +1,3 @@
+Rails.application.routes.draw do
+  get "home/index"
+end

spec/generator_specs/e2e_template/files/spec/system/test_react_component_renders_spec.rb

@@ -0,0 +1,13 @@
+require "rails_helper"
+
+RSpec.describe "home/index", type: :system, js: true do
+  before do
+    driven_by(:selenium_headless)
+  end
+
+  it "renders the App component" do
+    visit "home/index"
+
+    expect(page.body).to match "App component"
+  end
+end

spec/generator_specs/e2e_template/template.rb

@@ -0,0 +1,21 @@
+# install react
+system("yarn add react react-dom @babel/preset-react")
+
+# update webpack presets for react
+package_json_path = Rails.root.join("./package.json")
+insert_into_file(
+  package_json_path,
+  %(      "@babel/preset-react",\n),
+  after: /"presets": \[\n/
+)
+
+# install rspec-rails
+system("bundle add rspec-rails --group development,test")
+system("bundle exec rails g rspec:install")
+
+# copy files
+directory(
+  Rails.root.join("../e2e_template/files"),
+  Rails.root,
+  force: true
+)

spec/generator_specs/generator_spec.rb

@@ -0,0 +1,169 @@
+require "pathname"
+require "rake"
+require "json"
+require "shakapacker/utils/misc"
+require "shakapacker/utils/version_syntax_converter"
+
+GEM_ROOT = Pathname.new(File.expand_path("../../..", __FILE__))
+SPEC_PATH = Pathname.new(File.expand_path("../", __FILE__))
+BASE_RAILS_APP_PATH = SPEC_PATH.join("base-rails-app")
+TEMP_RAILS_APP_PATH = SPEC_PATH.join("temp-rails-app")
+
+describe "Generator" do
+  before :all do
+    # Don't use --skip-git because we want .gitignore file to exist in the project
+    sh_in_dir(SPEC_PATH, %(
+      rails new base-rails-app --skip-javascript --skip-bundle --skip-spring
+      rm -rf base-rails-app/.git
+    ))
+
+    Bundler.with_unbundled_env do
+      sh_in_dir(BASE_RAILS_APP_PATH, %(
+        gem update bundler
+        bundle add shakapacker --path "#{GEM_ROOT}"
+      ))
+    end
+  end
+
+  after :all do
+    Dir.chdir(SPEC_PATH)
+    FileUtils.rm_rf(BASE_RAILS_APP_PATH)
+  end
+
+  describe "shakapacker:install" do
+    context "in a normal Rails project" do
+      before :all do
+        sh_in_dir(SPEC_PATH, "cp -r #{BASE_RAILS_APP_PATH} #{TEMP_RAILS_APP_PATH}")
+
+        Bundler.with_unbundled_env do
+          sh_in_dir(TEMP_RAILS_APP_PATH, "FORCE=true bundle exec rails shakapacker:install")
+        end
+      end
+
+      after :all do
+        Dir.chdir(SPEC_PATH)
+        FileUtils.rm_rf(TEMP_RAILS_APP_PATH)
+      end
+
+      it "creates `config/shakapacker.yml`" do
+        config_file_relative_path = "config/shakapacker.yml"
+        actual_content = read(path_in_the_app(config_file_relative_path))
+        expected_content = read(path_in_the_gem(config_file_relative_path))
+
+        expect(actual_content).to eq expected_content
+      end
+
+      it "replaces package.json with template file" do
+        actual_content = read(path_in_the_app("package.json"))
+
+        expect(actual_content).to match /"name": "app",/
+      end
+
+      it "creates webpack config directory and its files" do
+        expected_files = [
+          "webpack.config.js"
+        ]
+
+        Dir.chdir(path_in_the_app("config/webpack")) do
+          exisiting_files_in_config_webpack_dir = Dir.glob("*")
+          expect(exisiting_files_in_config_webpack_dir).to eq expected_files
+        end
+      end
+
+      it "adds binstubs" do
+        expected_binstubs = []
+        Dir.chdir(File.join(GEM_ROOT, "lib/install/bin")) do
+          expected_binstubs = Dir.glob("bin/*")
+        end
+
+        Dir.chdir(File.join(TEMP_RAILS_APP_PATH, "bin")) do
+          actual_binstubs = Dir.glob("*")
+          expect(actual_binstubs).to include(*expected_binstubs)
+        end
+      end
+
+      it "modifies .gitignore" do
+        actual_content = read(path_in_the_app(".gitignore"))
+
+        expect(actual_content).to match ".yarn-integrity"
+      end
+
+      it 'adds <%= javascript_pack_tag "application" %>' do
+        actual_content = read(path_in_the_app("app/views/layouts/application.html.erb"))
+
+        expect(actual_content).to match '<%= javascript_pack_tag "application" %>'
+      end
+
+      it "updates `bin/setup" do
+        setup_file_content = read(path_in_the_app("bin/setup"))
+        expect(setup_file_content).to match %r(^\s*system!\(['"]bin/yarn['"]\))
+      end
+
+      it "adds relevant shakapacker version in package.json depending on gem version," do
+        npm_version = Shakapacker::Utils::VersionSyntaxConverter.new.rubygem_to_npm(Shakapacker::VERSION)
+
+        actual_content = read(path_in_the_app("package.json"))
+
+        expect(actual_content).to match /"shakapacker": "#{npm_version}",/
+      end
+
+      it "adds Shakapacker peer dependencies to package.json" do
+        package_json = JSON.parse(File.read(path_in_the_app("package.json")))
+        actual_dependencies = package_json["dependencies"]&.keys
+
+        expected_dependencies = %w(
+          @babel/core
+          @babel/plugin-transform-runtime
+          @babel/preset-env
+          @babel/runtime
+          babel-loader
+          compression-webpack-plugin
+          terser-webpack-plugin
+          webpack
+          webpack-assets-manifest
+          webpack-cli
+          webpack-merge
+        )
+
+        expect(actual_dependencies).to include(*expected_dependencies)
+      end
+
+      it "adds Shakapacker peer dev dependencies to package.json" do
+        package_json = JSON.parse(File.read(path_in_the_app("package.json")))
+        actual_dev_dependencies = package_json["devDependencies"]&.keys
+
+        expected_dev_dependencies = %w(
+          webpack-dev-server
+        )
+
+        expect(actual_dev_dependencies).to include(*expected_dev_dependencies)
+      end
+
+      context "with a basic react app setup" do
+        it "passes the test for rendering react component on the page" do
+          Bundler.with_unbundled_env do
+            sh_in_dir(TEMP_RAILS_APP_PATH, "./bin/rails app:template LOCATION=../e2e_template/template.rb")
+            expect(sh_in_dir(TEMP_RAILS_APP_PATH, "bundle exec rspec")).to be_truthy
+          end
+        end
+      end
+    end
+  end
+
+  private
+    def path_in_the_app(relative_path = nil)
+      Pathname.new(File.join([TEMP_RAILS_APP_PATH, relative_path].compact))
+    end
+
+    def path_in_the_gem(relative_path = nil)
+      Pathname.new(File.join([GEM_ROOT, "lib/install" , relative_path].compact))
+    end
+
+    def read(path)
+      File.read(path)
+    end
+
+    def sh_in_dir(dir, *shell_commands)
+      Shakapacker::Utils::Misc.sh_in_dir(dir, *shell_commands)
+    end
+end