hermes-agent/tests/hermes_cli/test_argparse_flag_propagation.py

"""Tests for parent→subparser flag propagation.

When flags like --yolo, -w, -s exist on both the parent parser and the 'chat'
subparser, placing the flag BEFORE the subcommand (e.g. 'hermes --yolo chat')
must not silently drop the flag value.

Regression test for: argparse subparser default=False overwriting parent's
parsed True when the same argument is defined on both parsers.

Fix: chat subparser uses default=argparse.SUPPRESS for all duplicated flags,
so the subparser only sets the attribute when the user explicitly provides it.
"""

import argparse
import os
import sys
from unittest.mock import patch

import pytest


def _build_parser():
    """Build the hermes argument parser from the real code.

    We import the real main() and extract the parser it builds.
    Since main() is a large function that does much more than parse args,
    we replicate just the parser structure here to avoid side effects.
    """
    parser = argparse.ArgumentParser(prog="hermes")
    parser.add_argument("--resume", "-r", metavar="SESSION", default=None)
    parser.add_argument(
        "--continue", "-c", dest="continue_last", nargs="?",
        const=True, default=None, metavar="SESSION_NAME",
    )
    parser.add_argument("--worktree", "-w", action="store_true", default=False)
    parser.add_argument("--skills", "-s", action="append", default=None)
    parser.add_argument("--yolo", action="store_true", default=False)
    parser.add_argument("--pass-session-id", action="store_true", default=False)

    subparsers = parser.add_subparsers(dest="command")
    chat = subparsers.add_parser("chat")
    # These MUST use argparse.SUPPRESS to avoid overwriting parent values
    chat.add_argument("--yolo", action="store_true",
                      default=argparse.SUPPRESS)
    chat.add_argument("--worktree", "-w", action="store_true",
                      default=argparse.SUPPRESS)
    chat.add_argument("--skills", "-s", action="append",
                      default=argparse.SUPPRESS)
    chat.add_argument("--pass-session-id", action="store_true",
                      default=argparse.SUPPRESS)
    chat.add_argument("--resume", "-r", metavar="SESSION_ID",
                      default=argparse.SUPPRESS)
    chat.add_argument(
        "--continue", "-c", dest="continue_last", nargs="?",
        const=True, default=argparse.SUPPRESS, metavar="SESSION_NAME",
    )
    return parser


class TestYoloEnvVar:
    """Verify --yolo sets HERMES_YOLO_MODE regardless of flag position.

    This tests the actual cmd_chat logic pattern (getattr → os.environ).
    """

    @pytest.fixture(autouse=True)
    def _clean_env(self):
        os.environ.pop("HERMES_YOLO_MODE", None)
        yield
        os.environ.pop("HERMES_YOLO_MODE", None)

    def _simulate_cmd_chat_yolo_check(self, args):
        """Replicate the exact check from cmd_chat in main.py."""
        if getattr(args, "yolo", False):
            os.environ["HERMES_YOLO_MODE"] = "1"

    def test_yolo_before_chat_sets_env(self):
        parser = _build_parser()
        args = parser.parse_args(["--yolo", "chat"])
        self._simulate_cmd_chat_yolo_check(args)
        assert os.environ.get("HERMES_YOLO_MODE") == "1"

    def test_yolo_after_chat_sets_env(self):
        parser = _build_parser()
        args = parser.parse_args(["chat", "--yolo"])
        self._simulate_cmd_chat_yolo_check(args)
        assert os.environ.get("HERMES_YOLO_MODE") == "1"

    def test_no_yolo_no_env(self):
        parser = _build_parser()
        args = parser.parse_args(["chat"])
        self._simulate_cmd_chat_yolo_check(args)
        assert os.environ.get("HERMES_YOLO_MODE") is None