CLI: --text/--file の同時指定を clap 競合で弾くようにし入力取得を簡素化

src/cli.rs

@@ -22,11 +22,11 @@ pub struct Cli {
 #[derive(Args)]
 pub struct CipherArgs {
     /// Text to process
-    #[arg(short, long)]
+    #[arg(short, long, conflicts_with = "file")]
     pub text: Option<String>,
 
     /// Input file path
-    #[arg(short = 'f', long)]
+    #[arg(short = 'f', long, conflicts_with = "text")]
     pub file: Option<String>,
 
     /// Shift value (any integer; safe mode: -25 to 25, default: 3)
@@ -57,11 +57,11 @@ pub enum Commands {
     /// Show all possible decryptions (brute force)
     BruteForce {
         /// Text to decrypt
-        #[arg(short, long)]
+        #[arg(short, long, conflicts_with = "file")]
         text: Option<String>,
 
         /// Input file path
-        #[arg(short = 'f', long)]
+        #[arg(short = 'f', long, conflicts_with = "text")]
         file: Option<String>,
     },
 }
@@ -136,52 +136,47 @@ pub fn run_cli() -> Result<(), Box<dyn std::error::Error>> {
 /// # Errors
 ///
 /// Returns an error if:
-/// - Both text and file are provided simultaneously
 /// - File reading fails
 /// - Stdin reading fails
 fn get_input_text(
     text: Option<String>,
     file: Option<String>,
 ) -> Result<String, Box<dyn std::error::Error>> {
-    match (text, file) {
-        (Some(t), None) => {
-            if t.len() > MAX_INPUT_SIZE {
-                return Err(format!(
-                    "Input text exceeds maximum size of {} bytes",
-                    MAX_INPUT_SIZE
-                )
-                .into());
-            }
-            Ok(t)
+    if let Some(t) = text {
+        if t.len() > MAX_INPUT_SIZE {
+            return Err(format!(
+                "Input text exceeds maximum size of {} bytes",
+                MAX_INPUT_SIZE
+            )
+            .into());
         }
-        (None, Some(f)) => {
-            let metadata =
-                fs::metadata(&f).map_err(|e| format!("Failed to read file '{}': {}", f, e))?;
-            if metadata.len() > MAX_INPUT_SIZE as u64 {
-                return Err(format!(
-                    "Input file '{}' exceeds maximum size of {} bytes",
-                    f, MAX_INPUT_SIZE
-                )
-                .into());
-            }
-            fs::read_to_string(&f).map_err(|e| format!("Failed to read file '{}': {}", f, e).into())
-        }
-        (Some(_), Some(_)) => Err("Cannot specify both text and file".into()),
-        (None, None) => {
-            print!("Enter text: ");
-            io::stdout().flush()?;
-            let mut input = String::new();
-            io::stdin().read_line(&mut input)?;
-            if input.len() > MAX_INPUT_SIZE {
-                return Err(format!(
-                    "Input text exceeds maximum size of {} bytes",
-                    MAX_INPUT_SIZE
-                )
-                .into());
-            }
-            Ok(trim_trailing_newline(&input).to_string())
+        return Ok(t);
+    }
+
+    if let Some(f) = file {
+        let metadata = fs::metadata(&f).map_err(|e| format!("Failed to read file '{}': {}", f, e))?;
+        if metadata.len() > MAX_INPUT_SIZE as u64 {
+            return Err(format!(
+                "Input file '{}' exceeds maximum size of {} bytes",
+                f, MAX_INPUT_SIZE
+            )
+            .into());
         }
+        return fs::read_to_string(&f).map_err(|e| format!("Failed to read file '{}': {}", f, e).into());
+    }
+
+    print!("Enter text: ");
+    io::stdout().flush()?;
+    let mut input = String::new();
+    io::stdin().read_line(&mut input)?;
+    if input.len() > MAX_INPUT_SIZE {
+        return Err(format!(
+            "Input text exceeds maximum size of {} bytes",
+            MAX_INPUT_SIZE
+        )
+        .into());
     }
+    Ok(input.trim().to_string())
 }
 
 fn trim_trailing_newline(input: &str) -> &str {
@@ -391,13 +386,10 @@ mod tests {
     }
 
     #[test]
-    fn test_get_input_text_both_provided() {
+    fn test_get_input_text_prefers_text_when_both_provided() {
         let result = get_input_text(Some("Hello".to_string()), Some("file.txt".to_string()));
-        assert!(result.is_err());
-        assert!(result
-            .unwrap_err()
-            .to_string()
-            .contains("Cannot specify both text and file"));
+        assert!(result.is_ok());
+        assert_eq!(result.unwrap(), "Hello");
     }
 
     #[test]

tests/cli_output_tests.rs

@@ -7,7 +7,7 @@
 //! | テスト観点                       | 分類     | 期待値                                |
 //! |----------------------------------|----------|---------------------------------------|
 //! | 存在しないファイル読込           | 異常系   | エラーメッセージにファイルパス含む    |
-//! | text+file同時指定                | 異常系   | "Cannot specify both" エラー          |
+//! | text+file同時指定                | 異常系   | clap が即エラーを返す                 |
 //! | テキスト引数のみ指定             | 正常系   | テキストがそのまま返る                |
 //! | ファイルから正常読込             | 正常系   | ファイル内容が返る                    |
 //! | 空ファイル読込                   | 境界値   | 空文字列返却                          |
@@ -180,10 +180,43 @@ fn test_cli_both_text_and_file_error() {
 
     let stderr = String::from_utf8_lossy(&output.stderr);
 
-    // Then: Error message mentions the conflict
+    // Then: clap validates conflict before application logic
+    assert!(!output.status.success(), "Command should fail on clap validation");
     assert!(
-        stderr.contains("Cannot specify both"),
-        "Error should mention 'Cannot specify both', got: {}",
+        stderr.contains("cannot be used with") || stderr.contains("conflicts with"),
+        "Error should mention clap conflict, got: {}",
+        stderr
+    );
+}
+
+#[test]
+fn test_cli_brute_force_both_text_and_file_error() {
+    // Given: Both text and file arguments provided for brute-force
+    let mut temp_file = NamedTempFile::new().unwrap();
+    write!(temp_file, "content").unwrap();
+    let file_path = temp_file.path().to_string_lossy().to_string();
+
+    // When: CLI receives both arguments
+    let output = std::process::Command::new("cargo")
+        .args([
+            "run",
+            "--",
+            "brute-force",
+            "--text",
+            "Khoor",
+            "--file",
+            &file_path,
+        ])
+        .output()
+        .expect("Failed to execute CLI");
+
+    let stderr = String::from_utf8_lossy(&output.stderr);
+
+    // Then: clap validates conflict before application logic
+    assert!(!output.status.success(), "Command should fail on clap validation");
+    assert!(
+        stderr.contains("cannot be used with") || stderr.contains("conflicts with"),
+        "Error should mention clap conflict, got: {}",
         stderr
     );
 }