refactor(console): close HelperSet to a fixed set of four helpers

Replace the dynamic, string-keyed HelperSet (set/has/get/get_iterator,
HelperSetKey, deprecated set_command/get_command) with a closed set of
FormatterHelper, DebugFormatterHelper, ProcessHelper and QuestionHelper
instantiated by an argument-less constructor and exposed through typed
getters (get_formatter/get_debug_formatter/get_process/get_question).

The typed getters let ProcessHelper, QuestionHelper::write_error and
InitCommand::interact drop their downcast/placeholder todo!() stubs.
Dynamic registration of plugin-provided helpers is intentionally dropped
for now and tracked via TODO(plugin) comments.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

2 files changed, 21 insertions, 53 deletions

diff --git a/crates/shirabe/src/command/init_command.rs b/crates/shirabe/src/command/init_command.rs
index f63014c..a04836d 100644
--- a/crates/shirabe/src/command/init_command.rs
+++ b/crates/shirabe/src/command/init_command.rs
@@ -7,7 +7,6 @@ use shirabe_external_packages::composer::pcre::{CaptureKey, Preg};
 use shirabe_external_packages::composer::spdx_licenses::SpdxLicenses;
 use shirabe_external_packages::symfony::console::command::command::Command;
 use shirabe_external_packages::symfony::console::helper::FormatBlockMessages;
-use shirabe_external_packages::symfony::console::helper::FormatterHelper;
 use shirabe_external_packages::symfony::console::input::ArrayInput;
 use shirabe_external_packages::symfony::console::input::InputInterface;
 use shirabe_external_packages::symfony::console::output::OutputInterface;
@@ -435,17 +434,16 @@ impl Command for InitCommand {
     fn interact(
         &mut self,
         input: Rc<RefCell<dyn InputInterface>>,
-        _output: Rc<RefCell<dyn OutputInterface>>,
+        output: Rc<RefCell<dyn OutputInterface>>,
     ) {
         let _ = (|| -> anyhow::Result<()> {
             let io = self.get_io();
             // @var FormatterHelper $formatter — PHP: $this->getHelperSet()->get('formatter')
-            // TODO(phase-c): get_helper_set returns PhpMixed and HelperSet::get is a todo!() stub (per
-            // the "Symfony stays todo!()" policy), so the typed FormatterHelper cannot be retrieved
-            // until the Helper trait + typed HelperSet are modelled.
-            let formatter: FormatterHelper = todo!();
-            let _ = &formatter;
-            let _ = self.get_helper_set();
+            let formatter = self
+                .get_helper_set()
+                .expect("the init command is registered on an application before interact() runs")
+                .borrow()
+                .get_formatter();
 
             // initialize repos if configured
             let repositories: Vec<String> = input
@@ -523,7 +521,7 @@ impl Command for InitCommand {
             io.write_error3(
                 &format!(
                     "\n{}\n",
-                    formatter.format_block(
+                    formatter.borrow().format_block(
                         FormatBlockMessages::String(
                             "Welcome to the Composer config generator".to_string(),
                         ),
@@ -695,6 +693,7 @@ impl Command for InitCommand {
                 }),
                 None,
                 minimum_stability_default
+                    .clone()
                     .map(PhpMixed::String)
                     .unwrap_or(PhpMixed::Null),
             )?;
@@ -796,8 +795,8 @@ impl Command for InitCommand {
             let requirements = if (require.len() as i64) > 0 || io.ask_confirmation(question, true)
             {
                 self.determine_requirements(
-                    input,
-                    _output,
+                    input.clone(),
+                    output.clone(),
                     require,
                     platform_repo.as_ref(),
                     &preferred_stability,
@@ -826,8 +825,8 @@ impl Command for InitCommand {
             let dev_requirements =
                 if (require_dev.len() as i64) > 0 || io.ask_confirmation(question, true) {
                     self.determine_requirements(
-                        input,
-                        _output,
+                        input.clone(),
+                        output.clone(),
                         require_dev,
                         platform_repo.as_ref(),
                         &preferred_stability,
diff --git a/crates/shirabe/src/console/application.rs b/crates/shirabe/src/console/application.rs
index c3287e7..8112e18 100644
--- a/crates/shirabe/src/console/application.rs
+++ b/crates/shirabe/src/console/application.rs
@@ -22,23 +22,18 @@ use shirabe_external_packages::symfony::console::exception::missing_input_except
 use shirabe_external_packages::symfony::console::exception::namespace_not_found_exception::NamespaceNotFoundException;
 use shirabe_external_packages::symfony::console::exception::runtime_exception::RuntimeException as ConsoleRuntimeException;
 use shirabe_external_packages::symfony::console::formatter::output_formatter::OutputFormatter;
-use shirabe_external_packages::symfony::console::helper::HelperInterface;
 use shirabe_external_packages::symfony::console::helper::HelperSet;
-use shirabe_external_packages::symfony::console::helper::HelperSetKey;
 use shirabe_external_packages::symfony::console::helper::QuestionHelper;
-use shirabe_external_packages::symfony::console::helper::debug_formatter_helper::DebugFormatterHelper;
 use shirabe_external_packages::symfony::console::helper::formatter_helper::{
     FormatBlockMessages, FormatterHelper,
 };
 use shirabe_external_packages::symfony::console::helper::helper::Helper;
-use shirabe_external_packages::symfony::console::helper::process_helper::ProcessHelper;
 use shirabe_external_packages::symfony::console::input::InputDefinition;
 use shirabe_external_packages::symfony::console::input::InputInterface;
 use shirabe_external_packages::symfony::console::input::InputOption;
 use shirabe_external_packages::symfony::console::input::argv_input::ArgvInput;
 use shirabe_external_packages::symfony::console::input::array_input::ArrayInput;
 use shirabe_external_packages::symfony::console::input::input_argument::InputArgument;
-use shirabe_external_packages::symfony::console::input::input_aware_interface::InputAwareInterface;
 use shirabe_external_packages::symfony::console::output::ConsoleOutputInterface;
 use shirabe_external_packages::symfony::console::output::console_output::ConsoleOutput;
 use shirabe_external_packages::symfony::console::output::output_interface::{
@@ -1633,33 +1628,10 @@ impl Application {
     }
 
     /// Gets the default helper set with the helpers that should always be available.
+    ///
+    /// The closed set of four helpers is instantiated by `HelperSet::new()` itself.
     pub fn get_default_helper_set(&self) -> std::rc::Rc<std::cell::RefCell<HelperSet>> {
-        let helper_set = std::rc::Rc::new(std::cell::RefCell::new(HelperSet::default()));
-        let helpers: IndexMap<HelperSetKey, std::rc::Rc<std::cell::RefCell<dyn HelperInterface>>> = {
-            let mut m: IndexMap<
-                HelperSetKey,
-                std::rc::Rc<std::cell::RefCell<dyn HelperInterface>>,
-            > = IndexMap::new();
-            m.insert(
-                HelperSetKey::Int(0),
-                std::rc::Rc::new(std::cell::RefCell::new(FormatterHelper::default())),
-            );
-            m.insert(
-                HelperSetKey::Int(1),
-                std::rc::Rc::new(std::cell::RefCell::new(DebugFormatterHelper::default())),
-            );
-            m.insert(
-                HelperSetKey::Int(2),
-                std::rc::Rc::new(std::cell::RefCell::new(ProcessHelper::default())),
-            );
-            m.insert(
-                HelperSetKey::Int(3),
-                std::rc::Rc::new(std::cell::RefCell::new(QuestionHelper::default())),
-            );
-            m
-        };
-        HelperSet::new(&helper_set, helpers);
-        helper_set
+        HelperSet::new()
     }
 
     /// Returns abbreviated suggestions in string format.
@@ -2887,15 +2859,12 @@ impl ApplicationHandle {
         output: std::rc::Rc<std::cell::RefCell<dyn OutputInterface>>,
     ) -> anyhow::Result<i32> {
         let application = &self.0;
-        if let Some(helper_set) = command.borrow().get_helper_set() {
-            for (_alias, helper) in helper_set.borrow().get_iterator() {
-                // if ($helper instanceof InputAwareInterface) $helper->setInput($input);
-                // TODO(review): downcasting a HelperInterface to InputAwareInterface is not
-                // expressible without a typed mechanism; needs design.
-                let _ = helper;
-                let _ = std::marker::PhantomData::<dyn InputAwareInterface>;
-            }
-        }
+        // PHP: foreach ($command->getHelperSet() as $helper) { if ($helper instanceof
+        // InputAwareInterface) $helper->setInput($input); }
+        // TODO(plugin): the HelperSet is now a closed set of four helpers, none of which implement
+        // InputAwareInterface, so this loop is a no-op. Plugin-registered InputAware helpers cannot
+        // be reached until dynamic helper registration is restored (see HelperSet).
+        let _ = command.borrow().get_helper_set();
 
         if !application.borrow().signals_to_dispatch_event.is_empty() {
             // $commandSignals = $command instanceof SignalableCommandInterface ? $command->getSubscribedSignals() : []