feat: confirm prompt for destructive slash commands (#4069) (#22687)

/clear, /new, /reset, and /undo now ask the user to confirm before
discarding conversation state — three-option prompt routed through the
existing tools.slash_confirm primitive.

Native yes/no buttons render on Telegram, Discord, and Slack (their
adapters already implement send_slash_confirm); other platforms get a
text-fallback prompt and reply with /approve, /always, or /cancel.

The classic prompt_toolkit CLI uses the same three-option flow via the
established _prompt_text_input pattern (see _confirm_and_reload_mcp).
TUI keeps its existing modal overlay (#12312).

Gated by new config key approvals.destructive_slash_confirm (default
true). Picking 'Always Approve' flips the gate to false so subsequent
destructive commands run silently — matches the established
mcp_reload_confirm UX.

Out of scope: /cron remove (separate domain — scheduled jobs, not
session history). Existing TUI overlay env-var (HERMES_TUI_NO_CONFIRM)
left unchanged; cosmetic unification can come later.

Closes #4069.

tests/cli/test_cli_new_session.py

@@ -130,6 +130,11 @@ def _prepare_cli_with_active_session(tmp_path):
     old_session_start = cli.session_start - timedelta(seconds=1)
     cli.session_start = old_session_start
     cli.agent.session_start = old_session_start
+
+    # Bypass the destructive-slash confirmation gate — these tests focus on
+    # the new-session mechanics, not the confirm prompt itself (covered in
+    # tests/cli/test_destructive_slash_confirm.py).
+    cli._confirm_destructive_slash = lambda *_a, **_kw: "once"
     return cli
 
 

tests/cli/test_destructive_slash_confirm.py

@@ -0,0 +1,152 @@
+"""Tests for cli.HermesCLI._confirm_destructive_slash.
+
+Drives the helper directly via __get__ on a SimpleNamespace stand-in so we
+don't have to construct a full HermesCLI (which requires extensive setup).
+"""
+
+from __future__ import annotations
+
+from types import SimpleNamespace
+from unittest.mock import patch
+
+
+def _bound(fn, instance):
+    """Bind an unbound method to a stand-in instance."""
+    return fn.__get__(instance, type(instance))
+
+
+def _make_self(prompt_response):
+    """Build a minimal stand-in 'self' for _confirm_destructive_slash."""
+    return SimpleNamespace(
+        _app=None,
+        _prompt_text_input=lambda _prompt: prompt_response,
+    )
+
+
+def test_gate_off_returns_once_without_prompting():
+    """When approvals.destructive_slash_confirm is False, return 'once'
+    immediately (caller proceeds without showing a prompt)."""
+    from cli import HermesCLI
+
+    self_ = _make_self(prompt_response="should not be called")
+
+    with patch(
+        "cli.load_cli_config",
+        return_value={"approvals": {"destructive_slash_confirm": False}},
+    ):
+        result = _bound(HermesCLI._confirm_destructive_slash, self_)(
+            "clear", "detail",
+        )
+
+    assert result == "once"
+
+
+def test_gate_on_choice_once_returns_once():
+    """When the gate is on and the user picks '1', return 'once'."""
+    from cli import HermesCLI
+
+    self_ = _make_self(prompt_response="1")
+
+    with patch(
+        "cli.load_cli_config",
+        return_value={"approvals": {"destructive_slash_confirm": True}},
+    ):
+        result = _bound(HermesCLI._confirm_destructive_slash, self_)(
+            "clear", "detail",
+        )
+
+    assert result == "once"
+
+
+def test_gate_on_choice_cancel_returns_none():
+    """When the user picks '3' (cancel), return None — caller must abort."""
+    from cli import HermesCLI
+
+    self_ = _make_self(prompt_response="3")
+
+    with patch(
+        "cli.load_cli_config",
+        return_value={"approvals": {"destructive_slash_confirm": True}},
+    ):
+        result = _bound(HermesCLI._confirm_destructive_slash, self_)(
+            "clear", "detail",
+        )
+
+    assert result is None
+
+
+def test_gate_on_no_input_returns_none():
+    """No input (None / EOF / Ctrl-C) treated as cancel."""
+    from cli import HermesCLI
+
+    self_ = _make_self(prompt_response=None)
+
+    with patch(
+        "cli.load_cli_config",
+        return_value={"approvals": {"destructive_slash_confirm": True}},
+    ):
+        result = _bound(HermesCLI._confirm_destructive_slash, self_)(
+            "clear", "detail",
+        )
+
+    assert result is None
+
+
+def test_gate_on_unknown_choice_returns_none():
+    """Garbage input is treated as cancel — fail safe, don't destroy state."""
+    from cli import HermesCLI
+
+    self_ = _make_self(prompt_response="maybe")
+
+    with patch(
+        "cli.load_cli_config",
+        return_value={"approvals": {"destructive_slash_confirm": True}},
+    ):
+        result = _bound(HermesCLI._confirm_destructive_slash, self_)(
+            "clear", "detail",
+        )
+
+    assert result is None
+
+
+def test_gate_on_choice_always_persists_and_returns_always():
+    """User picks 'always' → returns 'always' AND
+    save_config_value('approvals.destructive_slash_confirm', False) was called."""
+    from cli import HermesCLI
+
+    self_ = _make_self(prompt_response="2")
+
+    saves = []
+
+    def _fake_save(key, value):
+        saves.append((key, value))
+        return True
+
+    with patch(
+        "cli.load_cli_config",
+        return_value={"approvals": {"destructive_slash_confirm": True}},
+    ), patch("cli.save_config_value", _fake_save):
+        result = _bound(HermesCLI._confirm_destructive_slash, self_)(
+            "clear", "detail",
+        )
+
+    assert result == "always"
+    assert ("approvals.destructive_slash_confirm", False) in saves
+
+
+def test_gate_default_true_when_config_missing():
+    """If load_cli_config raises or returns malformed data, treat as
+    'gate on' (default safe) — must prompt."""
+    from cli import HermesCLI
+
+    self_ = _make_self(prompt_response="3")  # cancel
+
+    with patch("cli.load_cli_config", side_effect=Exception("boom")):
+        result = _bound(HermesCLI._confirm_destructive_slash, self_)(
+            "clear", "detail",
+        )
+
+    # Got prompted (returned None from cancel) — meaning the gate was
+    # treated as on despite the config error.  If the gate had been off
+    # this would have returned 'once' without consulting the prompt.
+    assert result is None