Files
hermes-agent/tests/hermes_cli/test_fallback_cmd.py
Teknium 1e37ddc929 feat(cli): add 'hermes fallback' command to manage fallback providers (#16052)
Manage the fallback_providers chain from the CLI instead of hand-editing
config.yaml. The picker reuses select_provider_and_model() from 'hermes
model' — same provider list, same credential prompts, same model picker.

  hermes fallback [list]   Show the current chain (primary + fallbacks)
  hermes fallback add      Run the model picker, append selection to chain
  hermes fallback remove   Pick an entry to delete (arrow-key menu)
  hermes fallback clear    Remove all entries (with confirmation)

'add' snapshots config['model'] before calling the picker, extracts the
user's selection from the post-picker state, then restores the primary
and appends {provider, model, base_url?, api_mode?} to fallback_providers.
Auth store's active_provider is snapshot/restored too so OAuth-provider
fallbacks don't silently deactivate the user's primary. Duplicates and
self-as-fallback are rejected. Legacy single-dict 'fallback_model' entries
are auto-migrated to the list format on first write.
2026-04-26 06:19:04 -07:00

487 lines
20 KiB
Python

"""Tests for `hermes fallback` — chain reading, add/remove/clear, legacy migration."""
from __future__ import annotations
import io
import types
from pathlib import Path
from unittest.mock import patch
import pytest
import yaml
# ---------------------------------------------------------------------------
# Shared fixture — isolate HERMES_HOME so save_config writes to tmp_path
# ---------------------------------------------------------------------------
@pytest.fixture()
def isolated_home(tmp_path, monkeypatch):
monkeypatch.setattr(Path, "home", lambda: tmp_path)
home = tmp_path / ".hermes"
home.mkdir(exist_ok=True)
monkeypatch.setenv("HERMES_HOME", str(home))
return tmp_path
def _write_config(home: Path, data: dict) -> None:
config_path = home / ".hermes" / "config.yaml"
config_path.write_text(yaml.safe_dump(data), encoding="utf-8")
def _read_config(home: Path) -> dict:
config_path = home / ".hermes" / "config.yaml"
return yaml.safe_load(config_path.read_text(encoding="utf-8")) or {}
# ---------------------------------------------------------------------------
# _read_chain / _write_chain
# ---------------------------------------------------------------------------
class TestReadChain:
def test_returns_empty_list_when_unset(self):
from hermes_cli.fallback_cmd import _read_chain
assert _read_chain({}) == []
def test_reads_new_list_format(self):
from hermes_cli.fallback_cmd import _read_chain
cfg = {
"fallback_providers": [
{"provider": "openrouter", "model": "anthropic/claude-sonnet-4.6"},
{"provider": "nous", "model": "Hermes-4-Llama-3.1-405B"},
]
}
assert _read_chain(cfg) == [
{"provider": "openrouter", "model": "anthropic/claude-sonnet-4.6"},
{"provider": "nous", "model": "Hermes-4-Llama-3.1-405B"},
]
def test_migrates_legacy_single_dict(self):
from hermes_cli.fallback_cmd import _read_chain
cfg = {"fallback_model": {"provider": "openrouter", "model": "gpt-5.4"}}
assert _read_chain(cfg) == [{"provider": "openrouter", "model": "gpt-5.4"}]
def test_skips_incomplete_entries(self):
from hermes_cli.fallback_cmd import _read_chain
cfg = {
"fallback_providers": [
{"provider": "openrouter"}, # missing model
{"model": "gpt-5.4"}, # missing provider
{"provider": "nous", "model": "foo"}, # valid
"not-a-dict", # noise
]
}
assert _read_chain(cfg) == [{"provider": "nous", "model": "foo"}]
def test_returns_copies_not_aliases(self):
from hermes_cli.fallback_cmd import _read_chain
cfg = {"fallback_providers": [{"provider": "nous", "model": "foo"}]}
result = _read_chain(cfg)
result[0]["provider"] = "mutated"
assert cfg["fallback_providers"][0]["provider"] == "nous"
# ---------------------------------------------------------------------------
# _extract_fallback_from_model_cfg
# ---------------------------------------------------------------------------
class TestExtractFallback:
def test_extracts_from_default_field(self):
from hermes_cli.fallback_cmd import _extract_fallback_from_model_cfg
model_cfg = {"provider": "openrouter", "default": "anthropic/claude-sonnet-4.6"}
assert _extract_fallback_from_model_cfg(model_cfg) == {
"provider": "openrouter",
"model": "anthropic/claude-sonnet-4.6",
}
def test_extracts_optional_base_url_and_api_mode(self):
from hermes_cli.fallback_cmd import _extract_fallback_from_model_cfg
model_cfg = {
"provider": "custom",
"default": "local-model",
"base_url": "http://localhost:11434/v1",
"api_mode": "chat_completions",
}
assert _extract_fallback_from_model_cfg(model_cfg) == {
"provider": "custom",
"model": "local-model",
"base_url": "http://localhost:11434/v1",
"api_mode": "chat_completions",
}
def test_returns_none_without_provider(self):
from hermes_cli.fallback_cmd import _extract_fallback_from_model_cfg
assert _extract_fallback_from_model_cfg({"default": "foo"}) is None
def test_returns_none_without_model(self):
from hermes_cli.fallback_cmd import _extract_fallback_from_model_cfg
assert _extract_fallback_from_model_cfg({"provider": "openrouter"}) is None
def test_returns_none_for_non_dict(self):
from hermes_cli.fallback_cmd import _extract_fallback_from_model_cfg
assert _extract_fallback_from_model_cfg("plain-string") is None
assert _extract_fallback_from_model_cfg(None) is None
# ---------------------------------------------------------------------------
# cmd_fallback_list
# ---------------------------------------------------------------------------
class TestListCommand:
def test_list_empty(self, isolated_home, capsys):
_write_config(isolated_home, {})
from hermes_cli.fallback_cmd import cmd_fallback_list
cmd_fallback_list(types.SimpleNamespace())
out = capsys.readouterr().out
assert "No fallback providers configured" in out
assert "hermes fallback add" in out
def test_list_with_entries(self, isolated_home, capsys):
_write_config(isolated_home, {
"model": {"provider": "anthropic", "default": "claude-sonnet-4-6"},
"fallback_providers": [
{"provider": "openrouter", "model": "anthropic/claude-sonnet-4.6"},
{"provider": "nous", "model": "Hermes-4"},
],
})
from hermes_cli.fallback_cmd import cmd_fallback_list
cmd_fallback_list(types.SimpleNamespace())
out = capsys.readouterr().out
assert "Fallback chain (2 entries)" in out
assert "anthropic/claude-sonnet-4.6" in out
assert "Hermes-4" in out
# Primary should be shown too
assert "claude-sonnet-4-6" in out
def test_list_migrates_legacy_for_display(self, isolated_home, capsys):
_write_config(isolated_home, {
"fallback_model": {"provider": "openrouter", "model": "gpt-5.4"},
})
from hermes_cli.fallback_cmd import cmd_fallback_list
cmd_fallback_list(types.SimpleNamespace())
out = capsys.readouterr().out
assert "1 entry" in out
assert "gpt-5.4" in out
# ---------------------------------------------------------------------------
# cmd_fallback_add — mock select_provider_and_model
# ---------------------------------------------------------------------------
class TestAddCommand:
def test_add_appends_new_entry(self, isolated_home, capsys):
_write_config(isolated_home, {
"model": {"provider": "anthropic", "default": "claude-sonnet-4-6"},
})
def fake_picker(args=None):
# Simulate what the real picker does: writes the selection to config["model"]
from hermes_cli.config import load_config, save_config
cfg = load_config()
cfg["model"] = {
"provider": "openrouter",
"default": "anthropic/claude-sonnet-4.6",
"base_url": "https://openrouter.ai/api/v1",
"api_mode": "chat_completions",
}
save_config(cfg)
with patch("hermes_cli.main.select_provider_and_model", side_effect=fake_picker), \
patch("hermes_cli.main._require_tty"):
from hermes_cli.fallback_cmd import cmd_fallback_add
cmd_fallback_add(types.SimpleNamespace())
cfg = _read_config(isolated_home)
# Primary is preserved
assert cfg["model"]["provider"] == "anthropic"
assert cfg["model"]["default"] == "claude-sonnet-4-6"
# Fallback was appended
assert cfg["fallback_providers"] == [
{
"provider": "openrouter",
"model": "anthropic/claude-sonnet-4.6",
"base_url": "https://openrouter.ai/api/v1",
"api_mode": "chat_completions",
}
]
out = capsys.readouterr().out
assert "Added fallback" in out
def test_add_rejects_duplicate(self, isolated_home, capsys):
_write_config(isolated_home, {
"model": {"provider": "anthropic", "default": "claude-sonnet-4-6"},
"fallback_providers": [
{"provider": "openrouter", "model": "gpt-5.4"},
],
})
def fake_picker(args=None):
from hermes_cli.config import load_config, save_config
cfg = load_config()
cfg["model"] = {"provider": "openrouter", "default": "gpt-5.4"}
save_config(cfg)
with patch("hermes_cli.main.select_provider_and_model", side_effect=fake_picker), \
patch("hermes_cli.main._require_tty"):
from hermes_cli.fallback_cmd import cmd_fallback_add
cmd_fallback_add(types.SimpleNamespace())
cfg = _read_config(isolated_home)
# Should still have exactly one entry
assert len(cfg["fallback_providers"]) == 1
out = capsys.readouterr().out
assert "already in the fallback chain" in out
def test_add_rejects_same_as_primary(self, isolated_home, capsys):
_write_config(isolated_home, {
"model": {"provider": "openrouter", "default": "gpt-5.4"},
})
def fake_picker(args=None):
# User picks the same thing that's already the primary
from hermes_cli.config import load_config, save_config
cfg = load_config()
cfg["model"] = {"provider": "openrouter", "default": "gpt-5.4"}
save_config(cfg)
with patch("hermes_cli.main.select_provider_and_model", side_effect=fake_picker), \
patch("hermes_cli.main._require_tty"):
from hermes_cli.fallback_cmd import cmd_fallback_add
cmd_fallback_add(types.SimpleNamespace())
cfg = _read_config(isolated_home)
assert "fallback_providers" not in cfg or cfg["fallback_providers"] == []
out = capsys.readouterr().out
assert "matches the current primary" in out
def test_add_preserves_primary_when_picker_changes_it(self, isolated_home):
"""The picker mutates config["model"]; fallback_add must restore the primary."""
_write_config(isolated_home, {
"model": {
"provider": "anthropic",
"default": "claude-sonnet-4-6",
"base_url": "https://api.anthropic.com",
"api_mode": "anthropic_messages",
},
})
def fake_picker(args=None):
from hermes_cli.config import load_config, save_config
cfg = load_config()
cfg["model"] = {
"provider": "openrouter",
"default": "anthropic/claude-sonnet-4.6",
"base_url": "https://openrouter.ai/api/v1",
"api_mode": "chat_completions",
}
save_config(cfg)
with patch("hermes_cli.main.select_provider_and_model", side_effect=fake_picker), \
patch("hermes_cli.main._require_tty"):
from hermes_cli.fallback_cmd import cmd_fallback_add
cmd_fallback_add(types.SimpleNamespace())
cfg = _read_config(isolated_home)
# Primary exactly as it was
assert cfg["model"]["provider"] == "anthropic"
assert cfg["model"]["default"] == "claude-sonnet-4-6"
assert cfg["model"]["base_url"] == "https://api.anthropic.com"
assert cfg["model"]["api_mode"] == "anthropic_messages"
# Fallback added
assert len(cfg["fallback_providers"]) == 1
assert cfg["fallback_providers"][0]["provider"] == "openrouter"
def test_add_noop_when_picker_cancelled(self, isolated_home, capsys):
_write_config(isolated_home, {
"model": {"provider": "anthropic", "default": "claude-sonnet-4-6"},
})
def fake_picker(args=None):
# User cancelled — no change to config
pass
with patch("hermes_cli.main.select_provider_and_model", side_effect=fake_picker), \
patch("hermes_cli.main._require_tty"):
from hermes_cli.fallback_cmd import cmd_fallback_add
cmd_fallback_add(types.SimpleNamespace())
cfg = _read_config(isolated_home)
assert "fallback_providers" not in cfg or cfg["fallback_providers"] == []
out = capsys.readouterr().out
# Either "No fallback added" (picker fully cancelled) or "matches the current primary"
# (picker left config untouched) — both indicate a non-add outcome.
assert ("No fallback added" in out) or ("matches the current primary" in out)
def test_add_noop_when_picker_clears_model(self, isolated_home, capsys):
"""Simulate picker explicitly clearing model.default (unusual but possible)."""
_write_config(isolated_home, {
"model": {"provider": "anthropic", "default": "claude-sonnet-4-6"},
})
def fake_picker(args=None):
from hermes_cli.config import load_config, save_config
cfg = load_config()
cfg["model"] = {"provider": "", "default": ""}
save_config(cfg)
with patch("hermes_cli.main.select_provider_and_model", side_effect=fake_picker), \
patch("hermes_cli.main._require_tty"):
from hermes_cli.fallback_cmd import cmd_fallback_add
cmd_fallback_add(types.SimpleNamespace())
out = capsys.readouterr().out
assert "No fallback added" in out
# ---------------------------------------------------------------------------
# cmd_fallback_remove
# ---------------------------------------------------------------------------
class TestRemoveCommand:
def test_remove_empty_chain(self, isolated_home, capsys):
_write_config(isolated_home, {})
from hermes_cli.fallback_cmd import cmd_fallback_remove
cmd_fallback_remove(types.SimpleNamespace())
out = capsys.readouterr().out
assert "nothing to remove" in out
def test_remove_selected_entry(self, isolated_home, capsys):
_write_config(isolated_home, {
"fallback_providers": [
{"provider": "openrouter", "model": "gpt-5.4"},
{"provider": "nous", "model": "Hermes-4"},
{"provider": "anthropic", "model": "claude-sonnet-4-6"},
],
})
# Picker returns index 1 (the middle entry, "nous / Hermes-4")
with patch("hermes_cli.setup._curses_prompt_choice", return_value=1):
from hermes_cli.fallback_cmd import cmd_fallback_remove
cmd_fallback_remove(types.SimpleNamespace())
cfg = _read_config(isolated_home)
assert cfg["fallback_providers"] == [
{"provider": "openrouter", "model": "gpt-5.4"},
{"provider": "anthropic", "model": "claude-sonnet-4-6"},
]
out = capsys.readouterr().out
assert "Removed fallback" in out
assert "Hermes-4" in out
def test_remove_cancel_keeps_chain(self, isolated_home):
_write_config(isolated_home, {
"fallback_providers": [
{"provider": "openrouter", "model": "gpt-5.4"},
],
})
# Cancel = last item (index == len(chain) == 1 in our menu)
with patch("hermes_cli.setup._curses_prompt_choice", return_value=1):
from hermes_cli.fallback_cmd import cmd_fallback_remove
cmd_fallback_remove(types.SimpleNamespace())
cfg = _read_config(isolated_home)
assert len(cfg["fallback_providers"]) == 1
# ---------------------------------------------------------------------------
# cmd_fallback_clear
# ---------------------------------------------------------------------------
class TestClearCommand:
def test_clear_empty_chain(self, isolated_home, capsys):
_write_config(isolated_home, {})
from hermes_cli.fallback_cmd import cmd_fallback_clear
cmd_fallback_clear(types.SimpleNamespace())
out = capsys.readouterr().out
assert "nothing to clear" in out
def test_clear_with_confirmation(self, isolated_home, capsys, monkeypatch):
_write_config(isolated_home, {
"fallback_providers": [
{"provider": "openrouter", "model": "gpt-5.4"},
{"provider": "nous", "model": "Hermes-4"},
],
})
monkeypatch.setattr("builtins.input", lambda *a, **kw: "y")
from hermes_cli.fallback_cmd import cmd_fallback_clear
cmd_fallback_clear(types.SimpleNamespace())
cfg = _read_config(isolated_home)
assert cfg.get("fallback_providers") == []
out = capsys.readouterr().out
assert "Fallback chain cleared" in out
def test_clear_cancelled(self, isolated_home, monkeypatch):
_write_config(isolated_home, {
"fallback_providers": [{"provider": "openrouter", "model": "gpt-5.4"}],
})
monkeypatch.setattr("builtins.input", lambda *a, **kw: "n")
from hermes_cli.fallback_cmd import cmd_fallback_clear
cmd_fallback_clear(types.SimpleNamespace())
cfg = _read_config(isolated_home)
assert len(cfg["fallback_providers"]) == 1
# ---------------------------------------------------------------------------
# cmd_fallback dispatcher
# ---------------------------------------------------------------------------
class TestDispatcher:
def test_no_subcommand_lists(self, isolated_home, capsys):
_write_config(isolated_home, {})
from hermes_cli.fallback_cmd import cmd_fallback
cmd_fallback(types.SimpleNamespace(fallback_command=None))
out = capsys.readouterr().out
assert "No fallback providers configured" in out
def test_list_alias(self, isolated_home, capsys):
_write_config(isolated_home, {})
from hermes_cli.fallback_cmd import cmd_fallback
cmd_fallback(types.SimpleNamespace(fallback_command="ls"))
out = capsys.readouterr().out
assert "No fallback providers configured" in out
def test_remove_alias(self, isolated_home, capsys):
_write_config(isolated_home, {})
from hermes_cli.fallback_cmd import cmd_fallback
cmd_fallback(types.SimpleNamespace(fallback_command="rm"))
out = capsys.readouterr().out
assert "nothing to remove" in out
def test_unknown_subcommand_exits(self, isolated_home):
_write_config(isolated_home, {})
from hermes_cli.fallback_cmd import cmd_fallback
with pytest.raises(SystemExit):
cmd_fallback(types.SimpleNamespace(fallback_command="nope"))
# ---------------------------------------------------------------------------
# argparse wiring — verify the subparser is registered
# ---------------------------------------------------------------------------
class TestArgparseWiring:
"""Verify `hermes fallback` is wired into main.py's argparse tree.
main() builds the parser inline, so we invoke main([...]) via subprocess
with --help to introspect registered subcommands without side effects.
"""
def test_fallback_help_lists_subcommands(self):
import subprocess
import sys
result = subprocess.run(
[sys.executable, "-m", "hermes_cli.main", "fallback", "--help"],
capture_output=True,
text=True,
timeout=30,
)
# --help exits 0
assert result.returncode == 0, f"stderr: {result.stderr}"
out = result.stdout + result.stderr
# All four subcommands should appear in help
assert "list" in out
assert "add" in out
assert "remove" in out
assert "clear" in out