refactor: streamline CLI utilities

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

Author: mrchypark

src/cli/error_handler.rs

@@ -51,7 +51,7 @@ impl ExitCode {
 }
 
 /// Categories of errors for better organization
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum ErrorCategory {
     /// User input related errors
     UserInput,
@@ -97,7 +97,7 @@ pub struct ErrorInfo {
 
 impl ErrorInfo {
     /// Creates a new ErrorInfo with basic information
-    pub fn new(category: ErrorCategory, exit_code: i32, message: String) -> Self {
+    pub const fn new(category: ErrorCategory, exit_code: i32, message: String) -> Self {
         Self {
             category,
             exit_code,
@@ -129,13 +129,13 @@ impl ErrorInfo {
     }
 
     /// Sets whether to show help information
-    pub fn with_help(mut self, show_help: bool) -> Self {
+    pub const fn with_help(mut self, show_help: bool) -> Self {
         self.show_help = show_help;
         self
     }
 
     /// Sets whether to use stderr for output
-    pub fn with_stderr(mut self, use_stderr: bool) -> Self {
+    pub const fn with_stderr(mut self, use_stderr: bool) -> Self {
         self.use_stderr = use_stderr;
         self
     }
@@ -162,7 +162,7 @@ pub struct ErrorHandler {
 
 impl ErrorHandler {
     /// Creates a new error handler with default settings
-    pub fn new() -> Self {
+    pub const fn new() -> Self {
         Self {
             use_korean: false, // Use English by default
             verbose: false,
@@ -171,7 +171,7 @@ impl ErrorHandler {
     }
 
     /// Creates a new error handler with custom settings
-    pub fn with_settings(use_korean: bool, verbose: bool, use_colors: bool) -> Self {
+    pub const fn with_settings(use_korean: bool, verbose: bool, use_colors: bool) -> Self {
         Self {
             use_korean,
             verbose,
@@ -654,13 +654,13 @@ impl ErrorHandler {
         // Print help information if requested
         if error_info.show_help {
             let _ = writeln!(stderr);
-            if self.use_korean {
-                let _ = writeln!(stderr, "To see help, run the following command:");
-                let _ = writeln!(stderr, "  libdplyr --help");
+            let help_intro = if self.use_korean {
+                "To see help, run the following command:"
             } else {
-                let _ = writeln!(stderr, "For help, run:");
-                let _ = writeln!(stderr, "  libdplyr --help");
-            }
+                "For help, run:"
+            };
+            let _ = writeln!(stderr, "{help_intro}");
+            let _ = writeln!(stderr, "  libdplyr --help");
         }
 
         let _ = stderr.flush();

src/cli/json_output.rs

@@ -128,23 +128,23 @@ pub struct JsonOutputFormatter {
 
 impl JsonOutputFormatter {
     /// Creates a new JSON output formatter
-    pub fn new() -> Self {
+    pub const fn new() -> Self {
         Self {
             pretty_print: false,
             include_debug: false,
         }
     }
 
     /// Creates a new JSON output formatter with pretty printing
-    pub fn pretty() -> Self {
+    pub const fn pretty() -> Self {
         Self {
             pretty_print: true,
             include_debug: false,
         }
     }
 
     /// Creates a new JSON output formatter with debug information
-    pub fn with_debug() -> Self {
+    pub const fn with_debug() -> Self {
         Self {
             pretty_print: false,
             include_debug: true,
@@ -283,17 +283,15 @@ impl JsonOutputFormatter {
         output: &JsonOutput,
         estimated_size: usize,
     ) -> JsonResult<String> {
+        let mut buf = String::with_capacity(estimated_size);
         if self.pretty_print {
-            let mut buf = String::with_capacity(estimated_size);
             let pretty_json = serde_json::to_string_pretty(output)?;
             buf.push_str(&pretty_json);
-            Ok(buf)
         } else {
-            let mut buf = String::with_capacity(estimated_size);
             let json = serde_json::to_string(output)?;
             buf.push_str(&json);
-            Ok(buf)
         }
+        Ok(buf)
     }
 }
 
@@ -338,7 +336,7 @@ impl MetadataBuilder {
     }
 
     /// Sets processing statistics
-    pub fn with_stats(mut self, stats: ProcessingStats) -> Self {
+    pub const fn with_stats(mut self, stats: ProcessingStats) -> Self {
         self.stats = stats;
         self
     }
@@ -373,7 +371,7 @@ impl MetadataBuilder {
 /// Helper functions for creating common metadata components
 impl ProcessingStats {
     /// Creates empty processing stats
-    pub fn empty() -> Self {
+    pub const fn empty() -> Self {
         Self {
             lex_time_us: 0,
             parse_time_us: 0,
@@ -387,7 +385,11 @@ impl ProcessingStats {
     }
 
     /// Creates processing stats with timing information
-    pub fn with_timing(lex_time_us: u64, parse_time_us: u64, generation_time_us: u64) -> Self {
+    pub const fn with_timing(
+        lex_time_us: u64,
+        parse_time_us: u64,
+        generation_time_us: u64,
+    ) -> Self {
         Self {
             lex_time_us,
             parse_time_us,

src/cli/output_formatter.rs

@@ -19,7 +19,7 @@ pub enum FormatError {
 }
 
 /// Output format types
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum OutputFormat {
     /// Default format - basic processing
     Default,
@@ -36,11 +36,11 @@ pub enum OutputFormat {
 impl fmt::Display for OutputFormat {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
-            OutputFormat::Default => write!(f, "default"),
-            OutputFormat::Basic => write!(f, "basic"),
-            OutputFormat::Pretty => write!(f, "pretty"),
-            OutputFormat::Compact => write!(f, "compact"),
-            OutputFormat::Json => write!(f, "json"),
+            Self::Default => write!(f, "default"),
+            Self::Basic => write!(f, "basic"),
+            Self::Pretty => write!(f, "pretty"),
+            Self::Compact => write!(f, "compact"),
+            Self::Json => write!(f, "json"),
         }
     }
 }
@@ -94,7 +94,7 @@ impl OutputFormatter {
     }
 
     /// Creates a new OutputFormatter with custom configuration
-    pub fn with_config(config: FormatConfig) -> Self {
+    pub const fn with_config(config: FormatConfig) -> Self {
         Self { config }
     }
 
@@ -259,7 +259,7 @@ impl OutputFormatter {
     }
 
     /// Gets the current format configuration
-    pub fn config(&self) -> &FormatConfig {
+    pub const fn config(&self) -> &FormatConfig {
         &self.config
     }
 
@@ -269,7 +269,7 @@ impl OutputFormatter {
     }
 
     /// Updates just the output format
-    pub fn set_format(&mut self, format: OutputFormat) {
+    pub const fn set_format(&mut self, format: OutputFormat) {
         self.config.format = format;
     }
 }

src/cli/pipeline.rs

@@ -32,7 +32,7 @@ pub struct CliArgs {
 }
 
 /// Supported SQL dialect types
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum SqlDialectType {
     PostgreSql,
     MySql,
@@ -43,10 +43,10 @@ pub enum SqlDialectType {
 impl std::fmt::Display for SqlDialectType {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
-            SqlDialectType::PostgreSql => write!(f, "postgresql"),
-            SqlDialectType::MySql => write!(f, "mysql"),
-            SqlDialectType::Sqlite => write!(f, "sqlite"),
-            SqlDialectType::DuckDb => write!(f, "duckdb"),
+            Self::PostgreSql => write!(f, "postgresql"),
+            Self::MySql => write!(f, "mysql"),
+            Self::Sqlite => write!(f, "sqlite"),
+            Self::DuckDb => write!(f, "duckdb"),
         }
     }
 }
@@ -56,10 +56,10 @@ impl std::str::FromStr for SqlDialectType {
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         match s.to_lowercase().as_str() {
-            "postgresql" | "postgres" | "pg" => Ok(SqlDialectType::PostgreSql),
-            "mysql" => Ok(SqlDialectType::MySql),
-            "sqlite" => Ok(SqlDialectType::Sqlite),
-            "duckdb" | "duck" => Ok(SqlDialectType::DuckDb),
+            "postgresql" | "postgres" | "pg" => Ok(Self::PostgreSql),
+            "mysql" => Ok(Self::MySql),
+            "sqlite" => Ok(Self::Sqlite),
+            "duckdb" | "duck" => Ok(Self::DuckDb),
             _ => Err(format!("Unsupported SQL dialect: {s}")),
         }
     }
@@ -200,7 +200,7 @@ fn create_dialect(dialect_type: &SqlDialectType) -> Box<dyn SqlDialect> {
 }
 
 /// CLI operation modes
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum CliMode {
     /// File-based processing mode
     FileMode {
@@ -248,26 +248,28 @@ impl CliConfig {
 
     /// Determine the CLI mode based on arguments
     fn determine_mode(args: &CliArgs) -> CliMode {
-        if let Some(ref input_text) = args.input_text {
-            CliMode::TextMode {
+        args.input_text.as_ref().map_or_else(
+            || {
+                args.input_file.as_ref().map_or(
+                    CliMode::StdinMode {
+                        validate_only: args.validate_only,
+                        streaming: false, // Future extension
+                    },
+                    |input_file| CliMode::FileMode {
+                        input_file: input_file.clone(),
+                        output_file: args.output_file.clone(),
+                    },
+                )
+            },
+            |input_text| CliMode::TextMode {
                 input_text: input_text.clone(),
                 output_file: args.output_file.clone(),
-            }
-        } else if let Some(ref input_file) = args.input_file {
-            CliMode::FileMode {
-                input_file: input_file.clone(),
-                output_file: args.output_file.clone(),
-            }
-        } else {
-            CliMode::StdinMode {
-                validate_only: args.validate_only,
-                streaming: false, // Future extension
-            }
-        }
+            },
+        )
     }
 
     /// Determine output format based on arguments
-    fn determine_output_format(args: &CliArgs) -> OutputFormat {
+    const fn determine_output_format(args: &CliArgs) -> OutputFormat {
         if args.json_output {
             OutputFormat::Json
         } else if args.compact {
@@ -630,24 +632,20 @@ impl ProcessingPipeline {
 
     /// Check if processing should continue (signal handling)
     pub fn should_continue(&self) -> bool {
-        if let Some(ref handler) = self.signal_handler {
-            !handler.should_shutdown()
-        } else {
-            true
-        }
+        self.signal_handler
+            .as_ref()
+            .is_none_or(|handler| !handler.should_shutdown())
     }
 
     /// Check if the output pipe was closed
     pub fn pipe_closed(&self) -> bool {
-        if let Some(ref handler) = self.signal_handler {
-            handler.pipe_closed()
-        } else {
-            false
-        }
+        self.signal_handler
+            .as_ref()
+            .is_some_and(|handler| handler.pipe_closed())
     }
 
     /// Get configuration reference
-    pub fn config(&self) -> &CliConfig {
+    pub const fn config(&self) -> &CliConfig {
         &self.config
     }
 }

src/cli/signal_handler.rs

@@ -179,7 +179,7 @@ impl Default for SignalHandler {
 }
 
 /// Result of waiting for a signal
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum SignalWaitResult {
     /// Shutdown signal received (SIGINT/SIGTERM)
     Shutdown,
@@ -239,7 +239,7 @@ pub mod utils {
     }
 
     /// Check if we're running in a Unix-like environment
-    pub fn is_unix_like() -> bool {
+    pub const fn is_unix_like() -> bool {
         cfg!(unix)
     }
 
@@ -316,7 +316,7 @@ impl SignalAwareProcessor {
     }
 
     /// Get reference to the signal handler
-    pub fn signal_handler(&self) -> &SignalHandler {
+    pub const fn signal_handler(&self) -> &SignalHandler {
         &self.signal_handler
     }
 }

src/cli/stdin_reader.rs

@@ -76,7 +76,7 @@ impl StdinReader {
     }
 
     /// Creates a new StdinReader with custom configuration
-    pub fn with_config(config: StdinConfig) -> Self {
+    pub const fn with_config(config: StdinConfig) -> Self {
         Self {
             config,
             signal_handler: None,
@@ -320,12 +320,12 @@ impl StdinReader {
     }
 
     /// Gets the current stdin configuration
-    pub fn config(&self) -> &StdinConfig {
+    pub const fn config(&self) -> &StdinConfig {
         &self.config
     }
 
     /// Updates the stdin configuration
-    pub fn set_config(&mut self, config: StdinConfig) {
+    pub const fn set_config(&mut self, config: StdinConfig) {
         self.config = config;
     }
 }