From da4242198ff87e5cbc21c7308ab12d9ec3bc99d5 Mon Sep 17 00:00:00 2001
From: YeonGyu-Kim <code.yeon.gyu@gmail.com>
Date: Thu, 9 Apr 2026 21:04:50 +0900
Subject: [PATCH] fix(cli): emit JSON error for unsupported resumed slash
 commands in JSON mode

When claw --output-format json --resume <session> /commit (or /plugins, etc.)
encountered an 'unsupported resumed slash command' error, it called
eprintln!() and exit(2) directly, bypassing both the main() JSON error
handler and the output_format check.

Fix: in both the slash-command parse-error path and the run_resume_command
Err path, check output_format and emit a structured JSON error:

  {"type":"error","error":"unsupported resumed slash command","command":"/commit"}

Text mode unchanged (still exits 2 with prose to stderr).
Addresses the resumed-command parity gap (gaebal-gajae ROADMAP #26 track).
159 CLI tests pass, fmt clean.
---
 rust/crates/rusty-claude-cli/src/main.rs | 39 ++++++++++++++++++++++--
 1 file changed, 36 insertions(+), 3 deletions(-)

diff --git a/rust/crates/rusty-claude-cli/src/main.rs b/rust/crates/rusty-claude-cli/src/main.rs
index 41777a1..e2c156d 100644
--- a/rust/crates/rusty-claude-cli/src/main.rs
+++ b/rust/crates/rusty-claude-cli/src/main.rs
@@ -2217,11 +2217,33 @@ fn resume_session(session_path: &Path, commands: &[String], output_format: CliOu
         let command = match SlashCommand::parse(raw_command) {
             Ok(Some(command)) => command,
             Ok(None) => {
-                eprintln!("unsupported resumed command: {raw_command}");
+                if output_format == CliOutputFormat::Json {
+                    eprintln!(
+                        "{}",
+                        serde_json::json!({
+                            "type": "error",
+                            "error": format!("unsupported resumed command: {raw_command}"),
+                            "command": raw_command,
+                        })
+                    );
+                } else {
+                    eprintln!("unsupported resumed command: {raw_command}");
+                }
                 std::process::exit(2);
             }
             Err(error) => {
-                eprintln!("{error}");
+                if output_format == CliOutputFormat::Json {
+                    eprintln!(
+                        "{}",
+                        serde_json::json!({
+                            "type": "error",
+                            "error": error.to_string(),
+                            "command": raw_command,
+                        })
+                    );
+                } else {
+                    eprintln!("{error}");
+                }
                 std::process::exit(2);
             }
         };
@@ -2247,7 +2269,18 @@ fn resume_session(session_path: &Path, commands: &[String], output_format: CliOu
                 }
             }
             Err(error) => {
-                eprintln!("{error}");
+                if output_format == CliOutputFormat::Json {
+                    eprintln!(
+                        "{}",
+                        serde_json::json!({
+                            "type": "error",
+                            "error": error.to_string(),
+                            "command": raw_command,
+                        })
+                    );
+                } else {
+                    eprintln!("{error}");
+                }
                 std::process::exit(2);
             }
         }