"""
Tests for the agent error protocol.
"""
import pytest

from src.agents.protocol import AgentError


@pytest.mark.unit
class TestAgentError:
    """Tests for the AgentError exception."""

    def test_agent_error_defaults(self):
        """Test base AgentError with default agent name."""
        error = AgentError("Something went wrong")

        assert "Something went wrong" in str(error)
        assert error.agent_name == "unknown"

    def test_agent_error_carries_agent_name(self):
        """Agent name is stored and prefixed into the message."""
        error = AgentError("Research task failed", agent_name="librarian")

        assert error.agent_name == "librarian"
        assert str(error) == "[librarian] Research task failed"
        assert error.message == "Research task failed"

    def test_agent_error_is_catchable_as_exception(self):
        """AgentError participates in normal exception handling."""
        with pytest.raises(AgentError):
            raise AgentError("boom", agent_name="librarian")