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.

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

---

**To Do**

 - [ ] Consider returning early and raising if the application is not
   using PostgreSQL.

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 +1,12 @@
+module Suspenders
+  module Generators
+    class CiGenerator < Rails::Generators::Base
+      source_root File.expand_path("../../templates/ci", __FILE__)
+
+      def cifiles
+        empty_directory ".github/workflows"
+        template "ci.yml", ".github/workflows/ci.yml"
+      end
+    end
+  end
+end

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

@@ -0,0 +1,146 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+
+jobs:
+<%- if Bundler.rubygems.find_name("bundler-audit").any? -%>
+  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 File.exist?("bin/importmap") && File.exist?("package.json") -%>
+  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 Bundler.rubygems.find_name("standard").any? && File.exist?(".prettierrc") -%>
+  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
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version-file: .node-version
+
+      - name: Install modules
+        run: yarn install
+
+      - name: Run tests
+        env:
+          RAILS_ENV: test
+          DATABASE_URL: postgres://postgres:postgres@localhost:5432
+          # REDIS_URL: redis://localhost:6379/0
+        <%- if File.exist? "spec" -%>
+          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 File.exist? "spec" -%>
+          path: ${{ github.workspace }}/tmp/capybara
+        <%- else -%>
+          path: ${{ github.workspace }}/tmp/screenshots
+        <%- end -%>
+          if-no-files-found: ignore

test/generators/suspenders/ci_generator_test.rb

@@ -0,0 +1,26 @@
+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
+        run_generator
+
+        assert_file app_root(".github/workflows/ci.yml")
+      end
+
+      private
+
+      def restore_destination
+        remove_dir_if_exists ".github"
+      end
+    end
+  end
+end