test(#747): regression guard for #745 bare slash command hint contract (issue/pr/commit)

ROADMAP.md

@@ -7659,3 +7659,5 @@ Original filing (2026-04-18): the session emitted `SessionStart hook (completed)
 745. **`claw issue --output-format json` and all other direct-CLI slash commands (pr, commit, etc.) returned `hint: null` — the `bare_slash_command_guidance` message strings had no `\n` separator between short error and remediation text, so `split_error_hint` couldn't populate the hint field** — dogfooded 2026-05-26 on `92e053a1`. The #738 fix added `\n` to the `--resume SESSION /cmd` path but missed the direct-CLI path (e.g. `claw issue`, `claw pr`). The `bare_slash_command_guidance` function formats two message variants: resume-supported and non-resume; both lacked `\n`. Fix: add `\n` before the remediation text in both format strings. Source: Jobdori dogfood on `92e053a1`, 2026-05-26.
 
 746. **`claw --output-format json` (bare, no TTY, no prompt) returned `hint: null` — the non-TTY interactive-only guard error string had no `\n` separator, so `split_error_hint` couldn't extract the remediation text into `.hint`** — dogfooded 2026-05-26 on `3c5459a3`. The single-string message `"interactive_only: claw requires an interactive terminal (stdin is not a TTY and no prompt was provided \u2014 pipe a prompt or run in a TTY)"` contained the hint inline but no newline, so callers reading `.hint` got null and had to parse the prose `error` string. Fix: split at `\n` — short error `"interactive_only: claw requires an interactive terminal."` + hint `"Stdin is not a TTY…pipe a prompt with \`echo 'task' | claw\` or run \`claw\` in an interactive terminal."`. Source: Jobdori dogfood on `3c5459a3`, 2026-05-26.
+
+747. **ROADMAP #745 has no regression test: `claw issue/pr/commit --output-format json hint` could silently regress to null** — confirmed by gaebal-gajae on `3c5459a33`. Same pattern as #737, #742, #744. Fix: add `bare_slash_command_hint_745` test iterating `issue`, `pr`, `commit` and asserting `error_kind:"interactive_only"` + non-empty `hint` field. Source: gaebal-gajae dogfood on `3c5459a33`, fixed on `18e7744e`, 2026-05-26.

rust/crates/rusty-claude-cli/tests/output_format_contract.rs

@@ -1456,6 +1456,54 @@ fn diff_json_changed_file_count_deduplication_733() {
     );
 }
 
+#[test]
+fn bare_slash_command_hint_745() {
+    // #747/#745: claw <slash-cmd> --output-format json must return non-null hint.
+    // bare_slash_command_guidance() previously had no \n so split_error_hint returned hint:null.
+    use std::process::Command;
+    let root = unique_temp_dir("bare-slash-hint");
+    fs::create_dir_all(&root).expect("temp dir");
+    let bin = env!("CARGO_BIN_EXE_claw");
+
+    // issue and pr are non-resume-supported; commit is resume-supported.
+    // All must emit non-null hint in their interactive_only error envelope.
+    for cmd in &["issue", "pr", "commit"] {
+        let output = Command::new(bin)
+            .current_dir(&root)
+            .args(["--output-format", "json", cmd])
+            .env("ANTHROPIC_API_KEY", "test")
+            .output()
+            .expect("claw should run");
+        assert!(
+            !output.status.success(),
+            "claw {cmd} outside REPL must exit non-zero"
+        );
+        // Error envelope is on stderr (type:error path) or stdout
+        let stderr = String::from_utf8_lossy(&output.stderr)
+            .lines()
+            .filter(|l| l.starts_with('{'))
+            .collect::<Vec<_>>()
+            .join("");
+        let stdout = String::from_utf8_lossy(&output.stdout);
+        let raw = if !stderr.is_empty() {
+            stderr
+        } else {
+            stdout.trim().to_string()
+        };
+        let parsed: serde_json::Value = serde_json::from_str(&raw)
+            .unwrap_or_else(|_| panic!("claw {cmd} must emit JSON; got: {raw}"));
+        assert_eq!(
+            parsed["error_kind"], "interactive_only",
+            "claw {cmd} must have error_kind:interactive_only (#745)"
+        );
+        let hint = parsed["hint"].as_str().unwrap_or("");
+        assert!(
+            !hint.is_empty(),
+            "claw {cmd} --output-format json hint must be non-empty (#745); got null"
+        );
+    }
+}
+
 #[test]
 fn config_unsupported_section_json_hint_741() {
     // #744/#741: claw config <unknown-section> --output-format json must return