feat(command): implement --help output

14 files changed, 161 insertions, 110 deletions

diff --git a/Cargo.lock b/Cargo.lock
index b9de65e..089dfdf 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1023,6 +1023,7 @@ dependencies = [
  "indexmap",
  "regex",
  "serde",
+ "serde_json",
  "zip",
 ]
 
diff --git a/crates/shirabe-external-packages/src/symfony/console/command/help_command.rs b/crates/shirabe-external-packages/src/symfony/console/command/help_command.rs
index 321b640..d98152f 100644
--- a/crates/shirabe-external-packages/src/symfony/console/command/help_command.rs
+++ b/crates/shirabe-external-packages/src/symfony/console/command/help_command.rs
@@ -6,6 +6,7 @@ use crate::symfony::console::completion::completion_suggestions::{
     CompletionSuggestions, StringOrSuggestion,
 };
 use crate::symfony::console::descriptor::application_description::ApplicationDescription;
+use crate::symfony::console::descriptor::descriptor_interface::DescribableObject;
 use crate::symfony::console::helper::descriptor_helper::DescriptorHelper;
 use crate::symfony::console::input::input_argument::InputArgument;
 use crate::symfony::console::input::input_definition::DefinitionItem;
@@ -137,15 +138,12 @@ impl Command for HelpCommand {
             self.command = Some(application.borrow_mut().find(&command_name)?);
         }
 
-        let helper = DescriptorHelper::new();
-        // TODO: DescriptorHelper::describe2 takes the described object as Option<PhpMixed>,
-        // but PhpMixed cannot hold a Command. The Command/Application object mixing for
-        // describe needs a dedicated type (Phase C).
-        let object: Option<PhpMixed> = todo!();
+        let mut helper = DescriptorHelper::new();
+        let object = DescribableObject::Command(self.command.clone().unwrap());
         let mut options = indexmap::IndexMap::new();
         options.insert("format".to_string(), input.borrow().get_option("format")?);
         options.insert("raw_text".to_string(), input.borrow().get_option("raw")?);
-        let _ = helper.describe2(&mut *output.borrow_mut(), object, options);
+        helper.describe2(output.clone(), object, options)?;
 
         self.command = None;
 
diff --git a/crates/shirabe-external-packages/src/symfony/console/command/list_command.rs b/crates/shirabe-external-packages/src/symfony/console/command/list_command.rs
index 9edebe4..bfaece7 100644
--- a/crates/shirabe-external-packages/src/symfony/console/command/list_command.rs
+++ b/crates/shirabe-external-packages/src/symfony/console/command/list_command.rs
@@ -6,6 +6,7 @@ use crate::symfony::console::completion::completion_suggestions::{
     CompletionSuggestions, StringOrSuggestion,
 };
 use crate::symfony::console::descriptor::application_description::ApplicationDescription;
+use crate::symfony::console::descriptor::descriptor_interface::DescribableObject;
 use crate::symfony::console::helper::descriptor_helper::DescriptorHelper;
 use crate::symfony::console::input::input_argument::InputArgument;
 use crate::symfony::console::input::input_definition::DefinitionItem;
@@ -136,11 +137,8 @@ impl Command for ListCommand {
         input: Rc<RefCell<dyn InputInterface>>,
         output: Rc<RefCell<dyn OutputInterface>>,
     ) -> anyhow::Result<i64> {
-        let helper = DescriptorHelper::new();
-        // TODO: DescriptorHelper::describe2 takes the described object as Option<PhpMixed>,
-        // but PhpMixed cannot hold an Application. The Command/Application object mixing for
-        // describe needs a dedicated type (Phase C).
-        let object: Option<PhpMixed> = todo!();
+        let mut helper = DescriptorHelper::new();
+        let object = DescribableObject::Application(self.get_application().unwrap());
         let mut options = indexmap::IndexMap::new();
         options.insert("format".to_string(), input.borrow().get_option("format")?);
         options.insert("raw_text".to_string(), input.borrow().get_option("raw")?);
@@ -149,7 +147,7 @@ impl Command for ListCommand {
             input.borrow().get_argument("namespace")?,
         );
         options.insert("short".to_string(), input.borrow().get_option("short")?);
-        let _ = helper.describe2(&mut *output.borrow_mut(), object, options);
+        helper.describe2(output.clone(), object, options)?;
 
         Ok(0)
     }
diff --git a/crates/shirabe-external-packages/src/symfony/console/descriptor/descriptor.rs b/crates/shirabe-external-packages/src/symfony/console/descriptor/descriptor.rs
index 43b1094..38824a6 100644
--- a/crates/shirabe-external-packages/src/symfony/console/descriptor/descriptor.rs
+++ b/crates/shirabe-external-packages/src/symfony/console/descriptor/descriptor.rs
@@ -2,8 +2,9 @@
 
 use crate::symfony::console::application::Application;
 use crate::symfony::console::command::command::Command;
-use crate::symfony::console::descriptor::descriptor_interface::DescriptorInterface;
-use crate::symfony::console::exception::invalid_argument_exception::InvalidArgumentException;
+use crate::symfony::console::descriptor::descriptor_interface::{
+    DescribableObject, DescriptorInterface,
+};
 use crate::symfony::console::input::input_argument::InputArgument;
 use crate::symfony::console::input::input_definition::InputDefinition;
 use crate::symfony::console::input::input_option::InputOption;
@@ -20,52 +21,29 @@ pub trait Descriptor: DescriptorInterface {
     fn describe(
         &mut self,
         output: std::rc::Rc<std::cell::RefCell<dyn OutputInterface>>,
-        object: PhpMixed,
+        object: DescribableObject,
         options: IndexMap<String, PhpMixed>,
     ) -> anyhow::Result<()> {
         self.set_output(output);
 
-        // PHP dispatches via `$object instanceof ...`. The concrete runtime type of
-        // `object` must be recovered to route to the correct describe* method.
-        match true {
-            // case $object instanceof InputArgument:
-            _ if todo!("$object instanceof InputArgument") => {
-                let argument: InputArgument = todo!("downcast object to InputArgument");
+        // PHP dispatches via `$object instanceof ...`; the explicit `DescribableObject` enum makes
+        // that dispatch a `match`.
+        match object {
+            DescribableObject::InputArgument(argument) => {
                 self.describe_input_argument(&argument, options)?;
             }
-            // case $object instanceof InputOption:
-            _ if todo!("$object instanceof InputOption") => {
-                let option: InputOption = todo!("downcast object to InputOption");
+            DescribableObject::InputOption(option) => {
                 self.describe_input_option(&option, options)?;
             }
-            // case $object instanceof InputDefinition:
-            _ if todo!("$object instanceof InputDefinition") => {
-                let definition: InputDefinition = todo!("downcast object to InputDefinition");
+            DescribableObject::InputDefinition(definition) => {
                 self.describe_input_definition(&definition, options)?;
             }
-            // case $object instanceof Command:
-            _ if todo!("$object instanceof Command") => {
-                let mut command: Box<dyn Command> = todo!("downcast object to Command");
-                self.describe_command(command.as_mut(), options)?;
+            DescribableObject::Command(command) => {
+                self.describe_command(&mut *command.borrow_mut(), options)?;
             }
-            // case $object instanceof Application:
-            _ if todo!("$object instanceof Application") => {
-                let application: std::rc::Rc<std::cell::RefCell<dyn Application>> =
-                    todo!("downcast object to Application");
+            DescribableObject::Application(application) => {
                 self.describe_application(application, options)?;
             }
-            _ => {
-                return Err(
-                    InvalidArgumentException(shirabe_php_shim::InvalidArgumentException {
-                        message: format!(
-                            "Object of type \"{}\" is not describable.",
-                            shirabe_php_shim::get_debug_type(&object)
-                        ),
-                        code: 0,
-                    })
-                    .into(),
-                );
-            }
         }
 
         Ok(())
diff --git a/crates/shirabe-external-packages/src/symfony/console/descriptor/descriptor_interface.rs b/crates/shirabe-external-packages/src/symfony/console/descriptor/descriptor_interface.rs
index be39ec3..be0e9ff 100644
--- a/crates/shirabe-external-packages/src/symfony/console/descriptor/descriptor_interface.rs
+++ b/crates/shirabe-external-packages/src/symfony/console/descriptor/descriptor_interface.rs
@@ -1,15 +1,29 @@
 //! ref: composer/vendor/symfony/console/Descriptor/DescriptorInterface.php
 
+use crate::symfony::console::application::Application;
+use crate::symfony::console::command::command::Command;
+use crate::symfony::console::input::input_argument::InputArgument;
+use crate::symfony::console::input::input_definition::InputDefinition;
+use crate::symfony::console::input::input_option::InputOption;
 use crate::symfony::console::output::output_interface::OutputInterface;
 use indexmap::IndexMap;
 use shirabe_php_shim::PhpMixed;
 
+/// The set of objects the descriptors know how to describe.
+pub enum DescribableObject {
+    InputArgument(InputArgument),
+    InputOption(InputOption),
+    InputDefinition(InputDefinition),
+    Command(std::rc::Rc<std::cell::RefCell<dyn Command>>),
+    Application(std::rc::Rc<std::cell::RefCell<dyn Application>>),
+}
+
 /// Descriptor interface.
 pub trait DescriptorInterface {
     fn describe(
         &mut self,
         output: std::rc::Rc<std::cell::RefCell<dyn OutputInterface>>,
-        object: PhpMixed,
+        object: DescribableObject,
         options: IndexMap<String, PhpMixed>,
     ) -> anyhow::Result<()>;
 }
diff --git a/crates/shirabe-external-packages/src/symfony/console/descriptor/json_descriptor.rs b/crates/shirabe-external-packages/src/symfony/console/descriptor/json_descriptor.rs
index 4793370..9068a0a 100644
--- a/crates/shirabe-external-packages/src/symfony/console/descriptor/json_descriptor.rs
+++ b/crates/shirabe-external-packages/src/symfony/console/descriptor/json_descriptor.rs
@@ -5,7 +5,9 @@ use crate::symfony::console::application::Application;
 use crate::symfony::console::command::command::Command;
 use crate::symfony::console::descriptor::application_description::ApplicationDescription;
 use crate::symfony::console::descriptor::descriptor::Descriptor;
-use crate::symfony::console::descriptor::descriptor_interface::DescriptorInterface;
+use crate::symfony::console::descriptor::descriptor_interface::{
+    DescribableObject, DescriptorInterface,
+};
 use crate::symfony::console::input::input_argument::InputArgument;
 use crate::symfony::console::input::input_definition::InputDefinition;
 use crate::symfony::console::input::input_option::InputOption;
@@ -370,7 +372,7 @@ impl DescriptorInterface for JsonDescriptor {
     fn describe(
         &mut self,
         output: std::rc::Rc<std::cell::RefCell<dyn OutputInterface>>,
-        object: PhpMixed,
+        object: DescribableObject,
         options: IndexMap<String, PhpMixed>,
     ) -> anyhow::Result<()> {
         Descriptor::describe(self, output, object, options)
diff --git a/crates/shirabe-external-packages/src/symfony/console/descriptor/markdown_descriptor.rs b/crates/shirabe-external-packages/src/symfony/console/descriptor/markdown_descriptor.rs
index 698cc51..49d958f 100644
--- a/crates/shirabe-external-packages/src/symfony/console/descriptor/markdown_descriptor.rs
+++ b/crates/shirabe-external-packages/src/symfony/console/descriptor/markdown_descriptor.rs
@@ -5,7 +5,9 @@ use crate::symfony::console::application::Application;
 use crate::symfony::console::command::command::Command;
 use crate::symfony::console::descriptor::application_description::ApplicationDescription;
 use crate::symfony::console::descriptor::descriptor::Descriptor;
-use crate::symfony::console::descriptor::descriptor_interface::DescriptorInterface;
+use crate::symfony::console::descriptor::descriptor_interface::{
+    DescribableObject, DescriptorInterface,
+};
 use crate::symfony::console::helper::helper::Helper;
 use crate::symfony::console::input::input_argument::InputArgument;
 use crate::symfony::console::input::input_definition::InputDefinition;
@@ -26,7 +28,7 @@ impl MarkdownDescriptor {
     pub fn describe(
         &mut self,
         output: std::rc::Rc<std::cell::RefCell<dyn OutputInterface>>,
-        object: PhpMixed,
+        object: DescribableObject,
         options: IndexMap<String, PhpMixed>,
     ) -> anyhow::Result<()> {
         let decorated = output.borrow().is_decorated();
@@ -312,7 +314,7 @@ impl DescriptorInterface for MarkdownDescriptor {
     fn describe(
         &mut self,
         output: std::rc::Rc<std::cell::RefCell<dyn OutputInterface>>,
-        object: PhpMixed,
+        object: DescribableObject,
         options: IndexMap<String, PhpMixed>,
     ) -> anyhow::Result<()> {
         MarkdownDescriptor::describe(self, output, object, options)
diff --git a/crates/shirabe-external-packages/src/symfony/console/descriptor/text_descriptor.rs b/crates/shirabe-external-packages/src/symfony/console/descriptor/text_descriptor.rs
index 915e19e..6590384 100644
--- a/crates/shirabe-external-packages/src/symfony/console/descriptor/text_descriptor.rs
+++ b/crates/shirabe-external-packages/src/symfony/console/descriptor/text_descriptor.rs
@@ -5,7 +5,9 @@ use crate::symfony::console::application::Application;
 use crate::symfony::console::command::command::Command;
 use crate::symfony::console::descriptor::application_description::ApplicationDescription;
 use crate::symfony::console::descriptor::descriptor::Descriptor;
-use crate::symfony::console::descriptor::descriptor_interface::DescriptorInterface;
+use crate::symfony::console::descriptor::descriptor_interface::{
+    DescribableObject, DescriptorInterface,
+};
 use crate::symfony::console::formatter::output_formatter::OutputFormatter;
 use crate::symfony::console::helper::helper::Helper;
 use crate::symfony::console::input::input_argument::InputArgument;
@@ -549,7 +551,7 @@ impl DescriptorInterface for TextDescriptor {
     fn describe(
         &mut self,
         output: std::rc::Rc<std::cell::RefCell<dyn OutputInterface>>,
-        object: PhpMixed,
+        object: DescribableObject,
         options: IndexMap<String, PhpMixed>,
     ) -> anyhow::Result<()> {
         Descriptor::describe(self, output, object, options)
diff --git a/crates/shirabe-external-packages/src/symfony/console/descriptor/xml_descriptor.rs b/crates/shirabe-external-packages/src/symfony/console/descriptor/xml_descriptor.rs
index 4c65893..063f279 100644
--- a/crates/shirabe-external-packages/src/symfony/console/descriptor/xml_descriptor.rs
+++ b/crates/shirabe-external-packages/src/symfony/console/descriptor/xml_descriptor.rs
@@ -4,7 +4,9 @@ use crate::symfony::console::application::Application;
 use crate::symfony::console::command::command::Command;
 use crate::symfony::console::descriptor::application_description::ApplicationDescription;
 use crate::symfony::console::descriptor::descriptor::Descriptor;
-use crate::symfony::console::descriptor::descriptor_interface::DescriptorInterface;
+use crate::symfony::console::descriptor::descriptor_interface::{
+    DescribableObject, DescriptorInterface,
+};
 use crate::symfony::console::input::input_argument::InputArgument;
 use crate::symfony::console::input::input_definition::InputDefinition;
 use crate::symfony::console::input::input_option::InputOption;
@@ -372,7 +374,7 @@ impl DescriptorInterface for XmlDescriptor {
     fn describe(
         &mut self,
         output: std::rc::Rc<std::cell::RefCell<dyn OutputInterface>>,
-        object: PhpMixed,
+        object: DescribableObject,
         options: IndexMap<String, PhpMixed>,
     ) -> anyhow::Result<()> {
         Descriptor::describe(self, output, object, options)
diff --git a/crates/shirabe-external-packages/src/symfony/console/helper/descriptor_helper.rs b/crates/shirabe-external-packages/src/symfony/console/helper/descriptor_helper.rs
index a0e1b2b..521284b 100644
--- a/crates/shirabe-external-packages/src/symfony/console/helper/descriptor_helper.rs
+++ b/crates/shirabe-external-packages/src/symfony/console/helper/descriptor_helper.rs
@@ -1,6 +1,8 @@
 //! ref: composer/vendor/symfony/console/Helper/DescriptorHelper.php
 
-use crate::symfony::console::descriptor::descriptor_interface::DescriptorInterface;
+use crate::symfony::console::descriptor::descriptor_interface::{
+    DescribableObject, DescriptorInterface,
+};
 use crate::symfony::console::descriptor::json_descriptor::JsonDescriptor;
 use crate::symfony::console::descriptor::markdown_descriptor::MarkdownDescriptor;
 use crate::symfony::console::descriptor::text_descriptor::TextDescriptor;
@@ -39,16 +41,10 @@ impl DescriptorHelper {
             inner: Helper::default(),
             descriptors: IndexMap::new(),
         };
-        // The XML/JSON/Markdown descriptors do not yet expose a constructor
-        // (no `Default`/`new`); their construction is deferred until those
-        // descriptor types provide one.
-        let xml: Box<dyn DescriptorInterface> = todo!();
-        let json: Box<dyn DescriptorInterface> = todo!();
-        let md: Box<dyn DescriptorInterface> = todo!();
         this.register("txt", Box::new(TextDescriptor::default()))
-            .register("xml", xml)
-            .register("json", json)
-            .register("md", md);
+            .register("xml", Box::new(XmlDescriptor::default()))
+            .register("json", Box::new(JsonDescriptor::default()))
+            .register("md", Box::new(MarkdownDescriptor::default()));
         this
     }
 
@@ -60,11 +56,11 @@ impl DescriptorHelper {
     ///
     /// @throws InvalidArgumentException when the given format is not supported
     pub fn describe2(
-        &self,
-        output: &dyn OutputInterface,
-        object: Option<shirabe_php_shim::PhpMixed>,
+        &mut self,
+        output: std::rc::Rc<std::cell::RefCell<dyn OutputInterface>>,
+        object: DescribableObject,
         options: IndexMap<String, shirabe_php_shim::PhpMixed>,
-    ) -> Result<(), InvalidArgumentException> {
+    ) -> anyhow::Result<()> {
         let mut merged: IndexMap<String, shirabe_php_shim::PhpMixed> = IndexMap::new();
         merged.insert(
             "raw_text".to_string(),
@@ -85,23 +81,20 @@ impl DescriptorHelper {
         };
 
         if !self.descriptors.contains_key(&format) {
-            return Err(InvalidArgumentException(
-                shirabe_php_shim::InvalidArgumentException {
+            return Err(
+                InvalidArgumentException(shirabe_php_shim::InvalidArgumentException {
                     message: format!(
                         "Unsupported format \"{}\".",
                         shirabe_php_shim::PhpMixed::String(format.clone()),
                     ),
                     code: 0,
-                },
-            ));
+                })
+                .into(),
+            );
         }
 
-        let _ = (&self.descriptors[&format], output, object, options);
-        // `DescriptorInterface::describe` takes an owned
-        // `Rc<RefCell<dyn OutputInterface>>` and `&mut self`, while the helper
-        // only holds a shared `&dyn OutputInterface` and `&self`. Reconciling
-        // this ownership/mutability gap is a Phase C decision.
-        todo!("dispatch to DescriptorInterface::describe (Phase C ownership)");
+        let descriptor = self.descriptors.get_mut(&format).unwrap();
+        descriptor.describe(output, object, options)
     }
 
     /// Registers a descriptor.
diff --git a/crates/shirabe-external-packages/src/symfony/string/unicode_string.rs b/crates/shirabe-external-packages/src/symfony/string/unicode_string.rs
index 396dcf3..8917f20 100644
--- a/crates/shirabe-external-packages/src/symfony/string/unicode_string.rs
+++ b/crates/shirabe-external-packages/src/symfony/string/unicode_string.rs
@@ -6,12 +6,32 @@ pub struct UnicodeString {
 }
 
 impl UnicodeString {
-    pub fn new(_string: &str) -> Self {
-        todo!()
+    // TODO(phase-c): the real constructor runs `normalizer_normalize` (Unicode NFC normalization),
+    // which has no Rust std equivalent and would need a dedicated normalization implementation.
+    // Normalization is skipped here, which is only correct for already-NFC input such as ASCII.
+    pub fn new(string: &str) -> Self {
+        Self {
+            string: string.to_string(),
+        }
     }
 
-    pub fn width(&self, _ignore_unsupported_encoding: bool) -> i64 {
-        todo!()
+    // TODO(phase-c): ASCII-only provisional implementation. The faithful `width()` uses `wcswidth`
+    // with the Unicode width tables to treat wide characters as width 2 and skip zero-width /
+    // combining characters; here every character counts as width 1, correct only for ASCII. The
+    // ANSI/control-character stripping driven by `ignore_ansi_decoration` is likewise not handled.
+    pub fn width(&self, _ignore_ansi_decoration: bool) -> i64 {
+        let s = self.string.replace(['\x00', '\x05', '\x07'], "");
+        let s = s.replace("\r\n", "\n").replace('\r', "\n");
+
+        let mut width: i64 = 0;
+        for line in s.split('\n') {
+            let line_width = line.chars().count() as i64;
+            if line_width > width {
+                width = line_width;
+            }
+        }
+
+        width
     }
 
     pub fn length(&self) -> i64 {
diff --git a/crates/shirabe-php-shim/Cargo.toml b/crates/shirabe-php-shim/Cargo.toml
index b577c1f..abfe89e 100644
--- a/crates/shirabe-php-shim/Cargo.toml
+++ b/crates/shirabe-php-shim/Cargo.toml
@@ -10,6 +10,7 @@ fastrand.workspace = true
 indexmap.workspace = true
 regex.workspace = true
 serde.workspace = true
+serde_json.workspace = true
 zip.workspace = true
 
 [lints]
diff --git a/crates/shirabe-php-shim/src/lib.rs b/crates/shirabe-php-shim/src/lib.rs
index 6b8a229..5821819 100644
--- a/crates/shirabe-php-shim/src/lib.rs
+++ b/crates/shirabe-php-shim/src/lib.rs
@@ -492,8 +492,14 @@ pub fn array_keys<V>(_array: &IndexMap<String, V>) -> Vec<String> {
     _array.keys().cloned().collect()
 }
 
-pub fn str_replace(_search: &str, _replace: &str, _subject: &str) -> String {
-    todo!()
+pub fn str_replace(search: &str, replace: &str, subject: &str) -> String {
+    // PHP returns the subject unchanged when the search string is empty, whereas Rust's
+    // `str::replace` would insert `replace` between every character.
+    if search.is_empty() {
+        return subject.to_string();
+    }
+
+    subject.replace(search, replace)
 }
 
 pub fn php_to_string(value: &PhpMixed) -> String {
@@ -1362,8 +1368,35 @@ pub fn filesize(_path: &str) -> Option<i64> {
     std::fs::metadata(_path).ok().map(|m| m.len() as i64)
 }
 
-pub fn json_encode_ex<T: serde::Serialize + ?Sized>(_value: &T, _flags: i64) -> Option<String> {
-    todo!()
+pub fn json_encode_ex<T: serde::Serialize + ?Sized>(value: &T, flags: i64) -> Option<String> {
+    // serde_json's compact output already matches PHP's `json_encode` with both
+    // JSON_UNESCAPED_SLASHES and JSON_UNESCAPED_UNICODE set: forward slashes and non-ASCII
+    // characters are emitted verbatim. The two flags below re-apply PHP's default escaping when
+    // they are absent.
+    // TODO(phase-c): other flags (e.g. JSON_PRETTY_PRINT, JSON_HEX_*, JSON_THROW_ON_ERROR) are not
+    // handled yet; add them when a call site needs them.
+    let mut s = serde_json::to_string(value).ok()?;
+
+    if flags & JSON_UNESCAPED_SLASHES == 0 {
+        s = s.replace('/', "\\/");
+    }
+
+    if flags & JSON_UNESCAPED_UNICODE == 0 {
+        let mut out = String::with_capacity(s.len());
+        for c in s.chars() {
+            if (c as u32) <= 0x7F {
+                out.push(c);
+            } else {
+                let mut buf = [0u16; 2];
+                for unit in c.encode_utf16(&mut buf) {
+                    out.push_str(&format!("\\u{:04x}", unit));
+                }
+            }
+        }
+        s = out;
+    }
+
+    Some(s)
 }
 
 pub const JSON_INVALID_UTF8_IGNORE: i64 = 1048576;
@@ -1650,8 +1683,15 @@ pub fn feof(_stream: PhpMixed) -> bool {
     todo!()
 }
 
-pub fn str_replace_array(_search: &[String], _replace: &[String], _subject: &str) -> String {
-    todo!()
+pub fn str_replace_array(search: &[String], replace: &[String], subject: &str) -> String {
+    // PHP's array form of str_replace replaces each search element in order with the replace
+    // element at the same index, falling back to an empty string when replace is shorter.
+    let mut result = subject.to_string();
+    for (i, s) in search.iter().enumerate() {
+        let r = replace.get(i).map(String::as_str).unwrap_or("");
+        result = str_replace(s, r, &result);
+    }
+    result
 }
 
 pub fn file(_filename: &str, _flags: i64) -> Option<Vec<String>> {
diff --git a/crates/shirabe/src/console/application.rs b/crates/shirabe/src/console/application.rs
index 82aa03d..146767d 100644
--- a/crates/shirabe/src/console/application.rs
+++ b/crates/shirabe/src/console/application.rs
@@ -8,6 +8,7 @@ use shirabe_external_packages::composer::xdebug_handler::XdebugHandler;
 use shirabe_external_packages::seld::json_lint::ParsingException;
 use shirabe_external_packages::symfony::console::application::Application as BaseApplication;
 use shirabe_external_packages::symfony::console::command::Command as SymfonyCommand;
+use shirabe_external_packages::symfony::console::command::help_command::HelpCommand;
 use shirabe_external_packages::symfony::console::command::lazy_command::LazyCommand;
 use shirabe_external_packages::symfony::console::command::signalable_command_interface::SignalableCommandInterface;
 use shirabe_external_packages::symfony::console::command_loader::command_loader_interface::CommandLoaderInterface;
@@ -1371,15 +1372,6 @@ impl Application {
         // downcasts each plugin's CommandProvider capability — this is the Plugin API surface,
         // which is intentionally unimplemented (see TODO(plugin) above). Returns an empty list
         // until the plugin capability model exists.
-        let _ = self.get_composer(false, Some(false), None)?;
-        let _ = UnexpectedValueException {
-            message: String::new(),
-            code: 0,
-        };
-        let _: fn(PhpMixed, PhpMixed) -> PhpMixed = array_merge;
-        let _: fn(&PhpMixed) -> String = get_class;
-        let _ = shirabe_php_shim::ArrayObject::new(None);
-        let _: IndexMap<String, PhpMixed> = IndexMap::new();
 
         Ok(commands)
     }
@@ -1913,16 +1905,13 @@ impl Application {
             self.want_helps = false;
 
             let help_command = self.get("help")?;
-            // $helpCommand->setCommand($command);
-            // TODO(review): setCommand() is defined on HelpCommand, not on the concrete
-            // `SymfonyCommand`
-            // struct; calling it through the Rc<RefCell<dyn SymfonyCommand>> needs the
-            // SymfonyCommand-subclass
-            // representation decision (downcast to HelpCommand).
-            let _ = &command;
-            todo!("help_command.set_command(command)");
+            help_command
+                .borrow_mut()
+                .as_any_mut()
+                .downcast_mut::<HelpCommand>()
+                .expect("the help command is a HelpCommand instance")
+                .set_command(command);
 
-            #[allow(unreachable_code)]
             return Ok(help_command);
         }
 
@@ -2067,7 +2056,18 @@ impl Application {
         let commands_snapshot: Vec<std::rc::Rc<std::cell::RefCell<dyn SymfonyCommand>>> =
             self.commands.values().cloned().collect();
         for command in &commands_snapshot {
-            for alias in command.borrow().get_aliases() {
+            // A command's run() can re-enter find() (e.g. HelpCommand looks up the command it
+            // describes). That command is mutably borrowed for the duration of its run(), so it
+            // cannot be borrowed here. It is safe to skip: find() always completes this alias pass
+            // before returning a command, so any command currently executing already had its
+            // aliases registered in the earlier find() call that located it.
+            // TODO: this work-around could be solved.
+            let Ok(borrowed) = command.try_borrow() else {
+                continue;
+            };
+            let aliases = borrowed.get_aliases();
+            drop(borrowed);
+            for alias in aliases {
                 if !self.has(&alias) {
                     self.commands.insert(alias, command.clone());
                 }