Merge pull request rails#47492 from Shopify/bundle-add-platform

rails new: add x86_64-linux and aarch64-linux platforms by default

Author: byroot

railties/lib/rails/generators/app_base.rb

@@ -644,7 +644,17 @@ def target_rails_prerelease(self_command = "new")
       end
 
       def run_bundle
-        bundle_command("install", "BUNDLE_IGNORE_MESSAGES" => "1") if bundle_install?
+        if bundle_install?
+          bundle_command("install", "BUNDLE_IGNORE_MESSAGES" => "1")
+
+          # The vast majority of Rails apps will be deployed on `x86_64-linux`.
+          platform = ["--add-platform=x86_64-linux"]
+
+          # Users that develop on M1 mac may use docker and would need `aarch64-linux` as well.
+          platform << "--add-platform=aarch64-linux" if RUBY_PLATFORM.start_with?("arm64")
+
+          bundle_command("lock #{platform.join(" ")}", "BUNDLE_IGNORE_MESSAGES" => "1")
+        end
       end
 
       def run_javascript

railties/test/generators/shared_generator_tests.rb

@@ -366,9 +366,11 @@ def run_generator_using_prerelease(args)
 
       assert_file File.expand_path("Gemfile", project_path) do |gemfile|
         assert_equal "install", @bundle_commands[0]
+        assert_match "lock --add-platform", @bundle_commands[1]
+
         assert_equal gemfile[rails_gem_pattern], bundle_command_rails_gems[0]
 
-        assert_match %r"^exec rails (?:plugin )?new #{Regexp.escape Shellwords.join(expected_args)}", @bundle_commands[1]
+        assert_match %r"^exec rails (?:plugin )?new #{Regexp.escape Shellwords.join(expected_args)}", @bundle_commands[2]
         assert_equal gemfile[rails_gem_pattern], bundle_command_rails_gems[1]
       end
     end