Test with Rails main (#207)

This adds gemfiles for Rails `main` branch so that CI can provide early
warnings regarding compatibility with the upcoming version of Rails.
The corresponding `Gemfile.lock` files are excluded from version control
since they would quickly become stale.

.github/workflows/ci.yml

@@ -14,8 +14,10 @@ jobs:
           - Gemfile
           - gemfiles/rails_7_0_propshaft.gemfile
           - gemfiles/rails_7_1_propshaft.gemfile
+          - gemfiles/rails_main_propshaft.gemfile
           - gemfiles/rails_7_0_sprockets.gemfile
           - gemfiles/rails_7_1_sprockets.gemfile
+          - gemfiles/rails_main_sprockets.gemfile
         continue-on-error: [ false ]
 
     name: ${{ format('Tests (Ruby {0}, {1})', matrix.ruby-version, matrix.gemfile) }}
@@ -30,7 +32,7 @@ jobs:
 
       - name: Remove Gemfile lock
         run: |
-          rm $BUNDLE_GEMFILE.lock
+          rm -f $BUNDLE_GEMFILE.lock
 
       - name: Install Ruby
         uses: ruby/setup-ruby@v1

.gitignore

@@ -20,3 +20,6 @@
 /test/dummy/public/assets
 .byebug_history
 *.gem
+
+# Ignore Gemfile.lock files for Rails main branch.
+/gemfiles/rails_main*.gemfile.lock

Appraisals

@@ -17,3 +17,13 @@ appraise "rails_7_1_propshaft" do
   gem "rails", "~> 7.1.0"
   gem "propshaft"
 end
+
+appraise "rails_main_sprockets" do
+  gem "rails", github: "rails/rails", branch: "main"
+  gem "sprockets-rails"
+end
+
+appraise "rails_main_propshaft" do
+  gem "rails", github: "rails/rails", branch: "main"
+  gem "propshaft"
+end

gemfiles/rails_main_propshaft.gemfile

@@ -0,0 +1,23 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "rails", branch: "main", git: "https://github.com/rails/rails.git"
+gem "sqlite3"
+gem "propshaft"
+
+group :development do
+  gem "appraisal"
+end
+
+group :test do
+  gem "turbo-rails"
+  gem "stimulus-rails"
+  gem "byebug"
+  gem "rexml"
+  gem "capybara"
+  gem "selenium-webdriver"
+  gem "webdrivers"
+end
+
+gemspec path: "../"

gemfiles/rails_main_sprockets.gemfile

@@ -0,0 +1,23 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "rails", branch: "main", git: "https://github.com/rails/rails.git"
+gem "sqlite3"
+gem "sprockets-rails"
+
+group :development do
+  gem "appraisal"
+end
+
+group :test do
+  gem "turbo-rails"
+  gem "stimulus-rails"
+  gem "byebug"
+  gem "rexml"
+  gem "capybara"
+  gem "selenium-webdriver"
+  gem "webdrivers"
+end
+
+gemspec path: "../"

test/installer_test.rb

@@ -46,6 +46,10 @@ def with_new_rails_app
           gemfile = File.read("Gemfile")
           gemfile.gsub!(/^gem "importmap-rails".*/, "")
           gemfile << %(gem "importmap-rails", path: #{File.expand_path("..", __dir__).inspect}\n)
+          if Rails::VERSION::PRE == "alpha"
+            gemfile.gsub!(/^gem "rails".*/, "")
+            gemfile << %(gem "rails", path: #{Gem.loaded_specs["rails"].full_gem_path.inspect}\n)
+          end
           File.write("Gemfile", gemfile)
 
           run_command("bundle", "install")