Prefer rackup file specified by CLI (#2236)

Co-Authored-By: Cristian Rivera <cristian_rivera@me.com>
Co-authored-by: Artur Montenegro <artur.montenegro@tempest.com.br>
Co-authored-by: Nate Berkopec <nate.berkopec@gmail.com>

History.md

@@ -39,6 +39,7 @@
   * Fix `out_of_band` hook never executed if the number of worker threads is > 1 (#2177)
   * Fix ThreadPool#shutdown timeout accuracy (#2221)
   * Fix `UserFileDefaultOptions#fetch` to properly use `default` (#2233)
+  * Prefer the rackup file specified by the CLI (#2225)
 
 * Refactor
   * Remove unused loader argument from Plugin initializer (#2095)

lib/puma/dsl.rb

@@ -308,7 +308,7 @@ module Puma
     # @example
     #   rackup '/u/apps/lolcat/config.ru'
     def rackup(path)
-      @options[:rackup] = path.to_s
+      @options[:rackup] ||= path.to_s
     end
 
     def early_hints(answer=true)

test/config/with_rackup_from_dsl.rb

@@ -0,0 +1 @@
+rackup "test/rackup/hello-env.ru"

test/test_integration_single.rb

@@ -43,6 +43,17 @@ class TestIntegrationSingle < TestIntegration
     assert_equal 0, status
   end
 
+  def test_prefer_rackup_file_specified_by_cli
+    skip_unless_signal_exist? :TERM
+
+    cli_server "-C test/config/with_rackup_from_dsl.rb test/rackup/hello.ru"
+    connection = connect
+    reply = read_body(connection)
+    _, status = stop_server
+
+    assert_match("Hello World", reply)
+  end
+
   def test_term_not_accepts_new_connections
     skip_unless_signal_exist? :TERM
     skip_on :jruby