Treat internal encoding as non-external Ruby option

Author: justin808

react_on_rails/lib/generators/react_on_rails/templates/base/base/bin/shakapacker-precompile-hook

@@ -85,14 +85,14 @@ end
 # outright ("invalid switch in RUBYOPT"), so it can never appear here.
 ARGUMENT_TAKING_SHORT_RUBYOPT_SWITCHES = %w[I r].freeze unless defined?(ARGUMENT_TAKING_SHORT_RUBYOPT_SWITCHES)
 
-# True when RUBYOPT already pins a source encoding: a -E (including inside a short-option cluster
-# such as -wEUS-ASCII), or a --encoding/--external-encoding/--internal-encoding long option.
+# True when RUBYOPT already pins the external encoding: a -E (including inside a short-option cluster
+# such as -wEUS-ASCII), or a --encoding/--external-encoding long option.
 def rubyopt_pins_encoding?(rubyopt)
   rubyopt.split.any? { |token| rubyopt_token_pins_encoding?(token) }
 end
 
 def rubyopt_token_pins_encoding?(token)
-  return true if token.start_with?("--encoding", "--external-encoding", "--internal-encoding")
+  return true if token.start_with?("--encoding", "--external-encoding")
   return false unless token.start_with?("-") && !token.start_with?("--") && token.length > 1
 
   token[1..].each_char do |char|

react_on_rails/spec/react_on_rails/generators/install_generator_spec.rb

@@ -5169,7 +5169,7 @@ class ActiveSupport::TestCase
         expect(content).to include('[Encoding::US_ASCII, Encoding::ASCII_8BIT].include?(Encoding.find("locale"))')
         expect(content).to include('"LANG" => "C.UTF-8"')
         expect(content).to include('"LC_ALL" => "C.UTF-8"')
-        expect(content).to include('"RUBYOPT" => utf8_widened_rubyopt(ENV.fetch("RUBYOPT", ""))')
+        expect(content).to include('"RUBYOPT" => utf8_widened_rubyopt(subprocess_rubyopt(extra))')
         expect(content).to include('"REACT_ON_RAILS_SKIP_VALIDATION" => "true"')
         expect(content).to include('"RSC_BUNDLE_ONLY" => "true"')
         expect(content).to include('"CLIENT_BUNDLE_ONLY" => nil')

react_on_rails/spec/react_on_rails/shakapacker_precompile_hook_shared_spec.rb

@@ -238,8 +238,7 @@ def bad_overrides.each_key
 
       it "honors long-form encoding options" do
         ["--encoding=US-ASCII", "--encoding US-ASCII",
-         "--external-encoding=US-ASCII", "--external-encoding US-ASCII",
-         "--internal-encoding=US-ASCII", "--internal-encoding US-ASCII"].each do |rubyopt|
+         "--external-encoding=US-ASCII", "--external-encoding US-ASCII"].each do |rubyopt|
           with_locale_encoding(Encoding::US_ASCII) do
             with_env("RUBYOPT" => rubyopt) do
               expect(utf8_subprocess_env["RUBYOPT"]).to eq(rubyopt)
@@ -248,6 +247,16 @@ def bad_overrides.each_key
         end
       end
 
+      it "still pins UTF-8 when RUBYOPT only sets the internal encoding" do
+        ["--internal-encoding=US-ASCII", "--internal-encoding US-ASCII"].each do |rubyopt|
+          with_locale_encoding(Encoding::US_ASCII) do
+            with_env("RUBYOPT" => rubyopt) do
+              expect(utf8_subprocess_env["RUBYOPT"]).to eq("-EUTF-8 #{rubyopt}")
+            end
+          end
+        end
+      end
+
       it "still pins UTF-8 for argument-taking flags whose operand begins with E/K" do
         # -r/-I consume their operand, so -rEnglish / -rKconv / -IEpath are NOT encoding requests.
         # The pin must still be added (a regex that matched any E/K after - would wrongly skip these).

react_on_rails/spec/support/shakapacker_precompile_hook_shared.rb

@@ -91,14 +91,14 @@ def utf8_widened_rubyopt(rubyopt)
 # outright ("invalid switch in RUBYOPT"), so it can never appear here.
 ARGUMENT_TAKING_SHORT_RUBYOPT_SWITCHES = %w[I r].freeze unless defined?(ARGUMENT_TAKING_SHORT_RUBYOPT_SWITCHES)
 
-# True when RUBYOPT already pins a source encoding: a -E (including inside a short-option cluster
-# such as -wEUS-ASCII), or a --encoding/--external-encoding/--internal-encoding long option.
+# True when RUBYOPT already pins the external encoding: a -E (including inside a short-option cluster
+# such as -wEUS-ASCII), or a --encoding/--external-encoding long option.
 def rubyopt_pins_encoding?(rubyopt)
   rubyopt.split.any? { |token| rubyopt_token_pins_encoding?(token) }
 end
 
 def rubyopt_token_pins_encoding?(token)
-  return true if token.start_with?("--encoding", "--external-encoding", "--internal-encoding")
+  return true if token.start_with?("--encoding", "--external-encoding")
   return false unless token.start_with?("-") && !token.start_with?("--") && token.length > 1
 
   token[1..].each_char do |char|