docs: Add comprehensive Rustdoc for shell meta plugin

Co-authored-by: aider (openai/andrew/openrouter/sonoma-sky-alpha) <aider@aider.chat>

src/meta_plugin/shell.rs

@@ -3,6 +3,11 @@ use std::env;
 use crate::meta_plugin::{MetaPlugin, MetaPluginType};
 
 #[derive(Debug, Clone, Default)]
+/// Meta plugin for capturing shell environment information.
+///
+/// This plugin retrieves the current shell from the SHELL environment variable
+/// and provides it as metadata. It runs once during initialization and does not
+/// process input data.
 pub struct ShellMetaPlugin {
     is_finalized: bool,
     outputs: std::collections::HashMap<String, serde_yaml::Value>,
@@ -10,6 +15,25 @@ pub struct ShellMetaPlugin {
 }
 
 impl ShellMetaPlugin {
+    /// Creates a new ShellMetaPlugin instance.
+    ///
+    /// Initializes with default outputs and options, overridden by provided values.
+    /// Defaults to "shell" as the output key.
+    ///
+    /// # Arguments
+    ///
+    /// * `_options` - Optional configuration options (unused currently).
+    /// * `outputs` - Optional output mappings to override defaults.
+    ///
+    /// # Returns
+    ///
+    /// * `ShellMetaPlugin` - A new instance with processed options and outputs.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let plugin = ShellMetaPlugin::new(None, None);
+    /// ```
     pub fn new(
         _options: Option<std::collections::HashMap<String, serde_yaml::Value>>,
         outputs: Option<std::collections::HashMap<String, serde_yaml::Value>>,
@@ -44,14 +68,31 @@ impl ShellMetaPlugin {
 }
 
 impl MetaPlugin for ShellMetaPlugin {
+    /// Checks if the plugin has been finalized.
+    ///
+    /// # Returns
+    ///
+    /// * `bool` - True if finalized, false otherwise.
     fn is_finalized(&self) -> bool {
         self.is_finalized
     }
     
+    /// Sets the finalized state of the plugin.
+    ///
+    /// # Arguments
+    ///
+    /// * `finalized` - The new finalized state.
     fn set_finalized(&mut self, finalized: bool) {
         self.is_finalized = finalized;
     }
     
+    /// Finalizes the plugin without processing data.
+    ///
+    /// For this plugin, finalization is handled in `initialize`, so this returns empty metadata.
+    ///
+    /// # Returns
+    ///
+    /// * `MetaPluginResponse` - Response with no metadata and finalized state.
     fn finalize(&mut self) -> crate::meta_plugin::MetaPluginResponse {
         // If already finalized, don't process again
         if self.is_finalized {
@@ -70,6 +111,17 @@ impl MetaPlugin for ShellMetaPlugin {
         }
     }
 
+    /// Updates the plugin with data (not used for shell).
+    ///
+    /// Shell plugin doesn't process data streams; returns empty response unless not finalized.
+    ///
+    /// # Arguments
+    ///
+    /// * `_data` - Byte slice of input data (ignored).
+    ///
+    /// # Returns
+    ///
+    /// * `MetaPluginResponse` - Empty metadata response.
     fn update(&mut self, _data: &[u8]) -> crate::meta_plugin::MetaPluginResponse {
         // If already finalized, don't process more data
         if self.is_finalized {
@@ -85,10 +137,31 @@ impl MetaPlugin for ShellMetaPlugin {
         }
     }
 
+    /// Returns the type of this meta plugin.
+    ///
+    /// # Returns
+    ///
+    /// * `MetaPluginType::Shell` - The shell plugin type.
     fn meta_type(&self) -> MetaPluginType {
         MetaPluginType::Shell
     }
     
+    /// Initializes the plugin and extracts shell metadata.
+    ///
+    /// Retrieves the SHELL environment variable and adds it to metadata.
+    /// Marks the plugin as finalized after one run.
+    ///
+    /// # Returns
+    ///
+    /// * `MetaPluginResponse` - Response with shell metadata and finalized state.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let mut plugin = ShellMetaPlugin::new(None, None);
+    /// let response = plugin.initialize();
+    /// assert!(response.is_finalized);
+    /// ```
     fn initialize(&mut self) -> crate::meta_plugin::MetaPluginResponse {
         // If already finalized, don't process again
         if self.is_finalized {
@@ -122,24 +195,48 @@ impl MetaPlugin for ShellMetaPlugin {
         }
     }
     
+    /// Returns a reference to the plugin's outputs.
+    ///
+    /// # Returns
+    ///
+    /// * `&HashMap<String, serde_yaml::Value>` - The outputs map.
     fn outputs(&self) -> &std::collections::HashMap<String, serde_yaml::Value> {
         &self.outputs
     }
     
+    /// Returns a mutable reference to the plugin's outputs.
+    ///
+    /// # Returns
+    ///
+    /// * `&mut HashMap<String, serde_yaml::Value>` - Mutable outputs map.
     fn outputs_mut(&mut self) -> &mut std::collections::HashMap<String, serde_yaml::Value> {
         &mut self.outputs
     }
     
     
     
+    /// Returns a reference to the plugin's options.
+    ///
+    /// # Returns
+    ///
+    /// * `&HashMap<String, serde_yaml::Value>` - The options map.
     fn options(&self) -> &std::collections::HashMap<String, serde_yaml::Value> {
         &self.options
     }
     
+    /// Returns a mutable reference to the plugin's options.
+    ///
+    /// # Returns
+    ///
+    /// * `&mut HashMap<String, serde_yaml::Value>` - Mutable options map.
     fn options_mut(&mut self) -> &mut std::collections::HashMap<String, serde_yaml::Value> {
         &mut self.options
     }
 }
+/// Registers the shell meta plugin with the global registry.
+///
+/// This constructor function is called at module load time using ctor crate.
+/// It creates the plugin with provided options and outputs.
 use crate::meta_plugin::register_meta_plugin;
 
 // Register the plugin at module initialization time