Introduce suspenders:ci generator

Creates CI template to be run via [GitHub Actions][ga] based on a
[similar template][ci template] that will be generated in an upcoming
Release of Rails.

Raises if the application is not using PostgreSQL, since our CI template
assumes that adapter.

Because this generator can be run in an existing application, we add
conditional checks for some jobs. However, this generator is intended
to be run as part of our holistic `suspenders:install:web` which will be
introduced in #1152.

Once Rails is released to contain a CI template, we will need to
consider how we want to handle conflicts between its file and ours, but
for now, we do not need to worry about that.

[ga]: https://docs.github.com/en/actions
[ci template]: rails/rails#50508

NEWS.md

@@ -16,6 +16,7 @@ Unreleased
 * Introduce `suspenders:email` generator
 * Introduce `suspenders:testing` generator
 * Introduce `suspenders:prerequisites` generator
+* Introduce `suspenders:ci` generator
 
 20230113.0 (January, 13, 2023)
 

README.md

@@ -188,6 +188,14 @@ Configures prerequisites. Currently Node.
 bin/rails g suspenders:prerequisites
 ```
 
+### CI
+
+CI
+
+```
+bin/rails g suspenders:ci
+```
+
 ## Contributing
 
 See the [CONTRIBUTING] document.

lib/generators/suspenders/ci_generator.rb

@@ -0,0 +1,50 @@
+module Suspenders
+  module Generators
+    class CiGenerator < Rails::Generators::Base
+      include Suspenders::Generators::DatabaseUnsupported
+      include Suspenders::Generators::Helpers
+
+      source_root File.expand_path("../../templates/ci", __FILE__)
+
+      def ci_files
+        empty_directory ".github/workflows"
+        template "ci.yml", ".github/workflows/ci.yml"
+      end
+
+      private
+
+      def scan_ruby?
+        has_gem? "bundler-audit"
+      end
+
+      def scan_js?
+        File.exist?("bin/importmap") && using_node?
+      end
+
+      def lint?
+        using_node? && has_gem?("standard") && has_yarn_script?("lint")
+      end
+
+      def using_node?
+        File.exist? "package.json"
+      end
+
+      def has_gem?(name)
+        Bundler.rubygems.find_name(name).any?
+      end
+
+      def using_rspec?
+        File.exist? "spec"
+      end
+
+      def has_yarn_script?(name)
+        return false if !using_node?
+
+        content = File.read("package.json")
+        json = JSON.parse(content)
+
+        json.dig("scripts", name)
+      end
+    end
+  end
+end

lib/generators/templates/ci/ci.yml.tt

@@ -0,0 +1,148 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+
+jobs:
+<%- if scan_ruby? -%>
+  scan_ruby:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: .ruby-version
+          bundler-cache: true
+
+      - name: Scan for security vulnerabilities in Ruby dependencies
+        run: |
+          bin/rails bundle:audit:update
+          bin/rails bundle:audit
+<% end -%>
+
+<%- if scan_js? -%>
+  scan_js:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: .ruby-version
+          bundler-cache: true
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version-file: .node-version
+
+      - name: Install modules
+        run: yarn install
+
+      - name: Scan for security vulnerabilities in JavaScript dependencies
+        run: |
+          bin/importmap audit
+          yarn audit
+<% end -%>
+
+<%- if lint? -%>
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: .ruby-version
+          bundler-cache: true
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version-file: .node-version
+
+      - name: Install modules
+        run: yarn install
+
+      - name: Lint Ruby code for consistent style
+        run: bin/rails standard
+
+      - name: Lint front-end code for consistent style
+        run: yarn lint
+<% end -%>
+
+  test:
+    runs-on: ubuntu-latest
+
+    services:
+      postgres:
+        image: postgres
+        env:
+          POSTGRES_USER: postgres
+          POSTGRES_PASSWORD: postgres
+        ports:
+          - 5432:5432
+        options: --health-cmd="pg_isready" --health-interval=10s --health-timeout=5s --health-retries=3
+
+      # redis:
+      #   image: redis
+      #   ports:
+      #     - 6379:6379
+      #   options: --health-cmd "redis-cli ping" --health-interval 10s --health-timeout 5s --health-retries 5
+
+    steps:
+      - name: Install packages
+        run: sudo apt-get update && sudo apt-get install --no-install-recommends -y google-chrome-stable curl libjemalloc2 libvips postgresql-client libpq-dev
+
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: .ruby-version
+          bundler-cache: true
+
+      <%- if using_node? -%>
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version-file: .node-version
+
+      - name: Install modules
+        run: yarn install
+      <%- end -%>
+
+      - name: Run tests
+        env:
+          RAILS_ENV: test
+          DATABASE_URL: postgres://postgres:postgres@localhost:5432
+          # REDIS_URL: redis://localhost:6379/0
+        <%- if using_rspec? -%>
+          run: bin/rails db:setup spec
+        <%- else -%>
+          run: bin/rails db:setup test test:system
+        <%- end -%>
+
+      - name: Keep screenshots from failed system tests
+        uses: actions/upload-artifact@v4
+        if: failure()
+        with:
+          name: screenshots
+        <%- if using_rspec? -%>
+          path: ${{ github.workspace }}/tmp/capybara
+        <%- else -%>
+          path: ${{ github.workspace }}/tmp/screenshots
+        <%- end -%>
+          if-no-files-found: ignore

lib/suspenders/generators.rb

@@ -44,5 +44,33 @@ def api_only_app?
           .match?(/^\s*config\.api_only\s*=\s*true/i)
       end
     end
+
+    module DatabaseUnsupported
+      class Error < StandardError
+        def message
+          "This generator requires PostgreSQL"
+        end
+      end
+
+      extend ActiveSupport::Concern
+
+      included do
+        def raise_if_database_unsupported
+          if database_unsupported?
+            raise Suspenders::Generators::DatabaseUnsupported::Error
+          end
+        end
+
+        private
+
+        def database_unsupported?
+          configuration = File.read(Rails.root.join("config/database.yml"))
+          configuration = YAML.load(configuration, aliases: true)
+          adapter = configuration["default"]["adapter"]
+
+          adapter != "postgresql"
+        end
+      end
+    end
   end
 end

test/generators/suspenders/ci_generator_test.rb

@@ -0,0 +1,38 @@
+require "test_helper"
+require "generators/suspenders/ci_generator"
+
+module Suspenders
+  module Generators
+    class CiGeneratorTest < Rails::Generators::TestCase
+      include Suspenders::TestHelpers
+
+      tests Suspenders::Generators::CiGenerator
+      destination Rails.root
+      teardown :restore_destination
+
+      test "generates CI template" do
+        with_database "postgresql" do
+          run_generator
+
+          assert_file app_root(".github/workflows/ci.yml")
+        end
+      end
+
+      test "raises if PostgreSQL is not the adapter" do
+        with_database "unsupported" do
+          assert_raises Suspenders::Generators::DatabaseUnsupported::Error, match: "This generator requires PostgreSQL" do
+            run_generator
+
+            assert_no_file app_root(".github/workflows/ci.yml")
+          end
+        end
+      end
+
+      private
+
+      def restore_destination
+        remove_dir_if_exists ".github"
+      end
+    end
+  end
+end

test/suspenders/generators_test.rb

@@ -8,4 +8,12 @@ class APIAppUnsupportedTest < Suspenders::GeneratorsTest
       assert_equal expected, Suspenders::Generators::APIAppUnsupported::Error.new.message
     end
   end
+
+  class DatabaseUnsupportedTest < Suspenders::GeneratorsTest
+    test "message returns a custom message" do
+      expected = "This generator requires PostgreSQL"
+
+      assert_equal expected, Suspenders::Generators::DatabaseUnsupported::Error.new.message
+    end
+  end
 end

test/test_helper.rb

@@ -100,6 +100,18 @@ def with_test_suite(test_suite, &block)
     remove_dir_if_exists "spec"
   end
 
+  def with_database(database, &block)
+    backup_file "config/database.yml"
+    configuration = File.read app_root("config/database.yml")
+    configuration = YAML.load(configuration, aliases: true)
+    configuration["default"]["adapter"] = database
+    File.open(app_root("config/database.yml"), "w") { _1.write configuration.to_yaml }
+
+    yield
+  ensure
+    restore_file "config/database.yml"
+  end
+
   def backup_file(file)
     FileUtils.copy app_root(file), app_root("#{file}.bak")
   end