Files
hermes-agent/tests/hermes_cli/test_codex_runtime_plugin_migration.py
T
Teknium1 71e323111e feat(codex-runtime): auto-migrate Hermes MCP servers to ~/.codex/config.toml
Translates the user's mcp_servers config from ~/.hermes/config.yaml into
the TOML format codex's MCP client expects. Wired into the
/codex-runtime codex_app_server enable path so users get their MCP tool
surface in the spawned subprocess automatically.

The migration runs on every enable. Failures are non-fatal — the runtime
change still proceeds and the user gets a warning so they can fix the
codex config manually.

What translates (mapping verified against codex-rs/core/src/config/edit.rs):
  Hermes mcp_servers.<n>.command/args/env  → codex stdio transport
  Hermes mcp_servers.<n>.url/headers       → codex streamable_http transport
  Hermes mcp_servers.<n>.timeout           → codex tool_timeout_sec
  Hermes mcp_servers.<n>.connect_timeout   → codex startup_timeout_sec
  Hermes mcp_servers.<n>.cwd               → codex stdio cwd
  Hermes mcp_servers.<n>.enabled: false    → codex enabled = false

What does NOT translate (warned + skipped per server):
  Hermes-specific keys (sampling, etc.) — codex's MCP client has no
  equivalent. Listed in the per-server skipped[] field of the report.

What's NOT migrated (intentional):
  AGENTS.md — codex respects this file natively in its cwd. Hermes' own
  AGENTS.md (project-level) is already in the worktree, so codex picks
  it up without translation. No code needed.

Idempotency design:
  All managed content lives between a 'managed by hermes-agent' marker
  and the next non-mcp_servers section header. _strip_existing_managed_block
  removes the prior managed region cleanly, preserving any user-added
  codex config (model, providers.openai, sandbox profiles, etc.) above
  or below.

Files added:
  hermes_cli/codex_runtime_plugin_migration.py — pure-Python migration
    helper. Public API: migrate(hermes_config, codex_home=None,
    dry_run=False) returns MigrationReport with .migrated/.errors/
    .skipped_keys_per_server. No external TOML dependency — minimal
    formatter handles strings/numbers/booleans/lists/inline-tables.

  tests/hermes_cli/test_codex_runtime_plugin_migration.py — 39 tests
  covering:
    - per-server translation (12): stdio/http/sse, cwd, timeouts,
      enabled flag, command+url precedence, sampling drop, unknown keys
    - TOML formatter (8): types, escaping, inline tables, error case
    - existing-block stripping (4): no marker, alone, with user content
      above, with user content below
    - end-to-end migrate() (8): empty, dry-run, round-trip, idempotent
      re-run, preserves user config, error reporting, invalid input,
      summary formatting

Files changed:
  hermes_cli/codex_runtime_switch.py — apply() now calls migrate() in
    the codex_app_server enable branch. Migration failure logs a warning
    in the result message but does NOT fail the runtime change. Disable
    path (auto) explicitly skips migration.

  tests/hermes_cli/test_codex_runtime_switch.py — 3 new tests:
    test_enable_triggers_mcp_migration, test_disable_does_not_trigger_migration,
    test_migration_failure_does_not_block_enable.

All 325 feature tests green:
  - tests/agent/transports/: 249 (incl. 67 new)
  - tests/run_agent/test_codex_app_server_integration.py: 9
  - tests/hermes_cli/test_codex_runtime_switch.py: 28 (3 new)
  - tests/hermes_cli/test_codex_runtime_plugin_migration.py: 39 (new)
2026-05-12 10:26:26 -07:00

338 lines
11 KiB
Python

"""Tests for the codex MCP plugin migration helper."""
from __future__ import annotations
from pathlib import Path
import pytest
from hermes_cli.codex_runtime_plugin_migration import (
MIGRATION_MARKER,
MigrationReport,
_format_toml_value,
_strip_existing_managed_block,
_translate_one_server,
migrate,
render_codex_toml_section,
)
# ---- per-server translation ----
class TestTranslateOneServer:
def test_stdio_basic(self):
cfg, skipped = _translate_one_server("filesystem", {
"command": "npx",
"args": ["-y", "@modelcontextprotocol/server-filesystem", "/tmp"],
"env": {"FOO": "bar"},
})
assert cfg == {
"command": "npx",
"args": ["-y", "@modelcontextprotocol/server-filesystem", "/tmp"],
"env": {"FOO": "bar"},
}
assert skipped == []
def test_stdio_with_cwd(self):
cfg, _ = _translate_one_server("custom", {
"command": "/usr/bin/myserver",
"cwd": "/var/lib/mcp",
})
assert cfg["cwd"] == "/var/lib/mcp"
def test_http_basic(self):
cfg, skipped = _translate_one_server("api", {
"url": "https://x.example/mcp",
"headers": {"Authorization": "Bearer abc"},
})
assert cfg == {
"url": "https://x.example/mcp",
"http_headers": {"Authorization": "Bearer abc"},
}
assert skipped == []
def test_sse_falls_under_streamable_http_with_warning(self):
cfg, skipped = _translate_one_server("sse_server", {
"url": "http://localhost:8000/sse",
"transport": "sse",
})
assert cfg["url"] == "http://localhost:8000/sse"
assert any("sse" in s.lower() for s in skipped)
def test_timeouts_translate(self):
cfg, _ = _translate_one_server("x", {
"command": "y",
"timeout": 180,
"connect_timeout": 30,
})
assert cfg["tool_timeout_sec"] == 180.0
assert cfg["startup_timeout_sec"] == 30.0
def test_non_numeric_timeout_skipped(self):
cfg, skipped = _translate_one_server("x", {
"command": "y",
"timeout": "not-a-number",
})
assert "tool_timeout_sec" not in cfg
assert any("timeout" in s and "numeric" in s for s in skipped)
def test_disabled_server_emits_enabled_false(self):
cfg, _ = _translate_one_server("x", {
"command": "y",
"enabled": False,
})
assert cfg["enabled"] is False
def test_enabled_true_omitted(self):
cfg, _ = _translate_one_server("x", {"command": "y", "enabled": True})
assert "enabled" not in cfg # codex defaults to true
def test_command_and_url_prefers_stdio_warns(self):
cfg, skipped = _translate_one_server("x", {
"command": "y", "url": "http://z",
})
assert "command" in cfg
assert "url" not in cfg
assert any("url" in s for s in skipped)
def test_no_transport_returns_none(self):
cfg, skipped = _translate_one_server("broken", {"description": "x"})
assert cfg is None
assert "no command or url" in skipped[0]
def test_sampling_dropped_with_warning(self):
cfg, skipped = _translate_one_server("x", {
"command": "y",
"sampling": {"enabled": True, "model": "gemini-3-flash"},
})
assert "sampling" not in cfg
assert any("sampling" in s for s in skipped)
def test_unknown_keys_warned(self):
cfg, skipped = _translate_one_server("x", {
"command": "y",
"totally_made_up_key": "value",
})
assert "totally_made_up_key" not in cfg
assert any("totally_made_up_key" in s for s in skipped)
def test_non_dict_input(self):
cfg, skipped = _translate_one_server("x", "notadict") # type: ignore[arg-type]
assert cfg is None
# ---- TOML rendering ----
class TestTomlValueFormatter:
def test_string_quoted(self):
assert _format_toml_value("hello") == '"hello"'
def test_string_with_quotes_escaped(self):
assert _format_toml_value('a"b') == '"a\\"b"'
def test_bool(self):
assert _format_toml_value(True) == "true"
assert _format_toml_value(False) == "false"
def test_int(self):
assert _format_toml_value(42) == "42"
def test_float(self):
assert _format_toml_value(180.0) == "180.0"
def test_list_of_strings(self):
assert _format_toml_value(["a", "b"]) == '["a", "b"]'
def test_inline_table(self):
out = _format_toml_value({"FOO": "bar"})
assert out == '{ FOO = "bar" }'
def test_empty_inline_table(self):
assert _format_toml_value({}) == "{}"
def test_unsupported_type_raises(self):
with pytest.raises(ValueError):
_format_toml_value(object())
class TestRenderToml:
def test_starts_with_marker(self):
out = render_codex_toml_section({})
assert out.startswith(MIGRATION_MARKER)
def test_empty_servers_emits_placeholder(self):
out = render_codex_toml_section({})
assert "no MCP servers" in out
def test_servers_sorted_alphabetically(self):
out = render_codex_toml_section({
"zoo": {"command": "z"},
"alpha": {"command": "a"},
"middle": {"command": "m"},
})
# Find the section header positions and confirm order
a_pos = out.find("[mcp_servers.alpha]")
m_pos = out.find("[mcp_servers.middle]")
z_pos = out.find("[mcp_servers.zoo]")
assert 0 < a_pos < m_pos < z_pos
def test_server_with_args_and_env(self):
out = render_codex_toml_section({
"fs": {
"command": "npx",
"args": ["-y", "filesystem"],
"env": {"PATH": "/usr/bin"},
}
})
assert "[mcp_servers.fs]" in out
assert 'command = "npx"' in out
assert 'args = ["-y", "filesystem"]' in out
# Env emitted as inline table
assert 'env = { PATH = "/usr/bin" }' in out
# ---- existing-block stripping ----
class TestStripExistingManagedBlock:
def test_no_managed_block_unchanged(self):
text = "[other]\nfoo = 1\n"
assert _strip_existing_managed_block(text) == text
def test_strips_managed_block_alone(self):
text = (
f"{MIGRATION_MARKER}\n"
"\n"
"[mcp_servers.fs]\n"
'command = "npx"\n'
)
assert _strip_existing_managed_block(text).strip() == ""
def test_preserves_user_content_above_managed_block(self):
text = (
"[model]\n"
'name = "gpt-5.5"\n'
"\n"
f"{MIGRATION_MARKER}\n"
"[mcp_servers.fs]\n"
'command = "x"\n'
)
out = _strip_existing_managed_block(text)
assert "[model]" in out
assert 'name = "gpt-5.5"' in out
assert "mcp_servers.fs" not in out
def test_preserves_unrelated_section_after_managed_block(self):
text = (
f"{MIGRATION_MARKER}\n"
"[mcp_servers.fs]\n"
'command = "x"\n'
"\n"
"[providers]\n"
'foo = "bar"\n'
)
out = _strip_existing_managed_block(text)
assert "mcp_servers.fs" not in out
assert "[providers]" in out
assert 'foo = "bar"' in out
# ---- end-to-end migrate() ----
class TestMigrate:
def test_no_servers_writes_placeholder(self, tmp_path):
report = migrate({}, codex_home=tmp_path)
assert report.written
text = (tmp_path / "config.toml").read_text()
assert MIGRATION_MARKER in text
assert "no MCP servers" in text
def test_dry_run_doesnt_write(self, tmp_path):
report = migrate({"mcp_servers": {"x": {"command": "y"}}},
codex_home=tmp_path, dry_run=True)
assert report.dry_run is True
assert not (tmp_path / "config.toml").exists()
assert "x" in report.migrated
def test_full_migration_round_trip(self, tmp_path):
hermes_cfg = {
"mcp_servers": {
"filesystem": {
"command": "npx",
"args": ["-y", "@modelcontextprotocol/server-filesystem"],
},
"github": {
"url": "https://api.github.com/mcp",
"headers": {"Authorization": "Bearer x"},
},
}
}
report = migrate(hermes_cfg, codex_home=tmp_path)
assert report.written
text = (tmp_path / "config.toml").read_text()
assert "[mcp_servers.filesystem]" in text
assert "[mcp_servers.github]" in text
assert 'command = "npx"' in text
assert 'url = "https://api.github.com/mcp"' in text
def test_idempotent_re_run_replaces_managed_block(self, tmp_path):
# First migration
migrate({"mcp_servers": {"a": {"command": "x"}}}, codex_home=tmp_path)
first_text = (tmp_path / "config.toml").read_text()
assert "[mcp_servers.a]" in first_text
# Second migration with different servers
migrate({"mcp_servers": {"b": {"command": "y"}}}, codex_home=tmp_path)
second_text = (tmp_path / "config.toml").read_text()
assert "[mcp_servers.a]" not in second_text
assert "[mcp_servers.b]" in second_text
def test_preserves_user_codex_config_above_marker(self, tmp_path):
target = tmp_path / "config.toml"
target.write_text(
"[model]\n"
'profile = "default"\n'
"\n"
"[providers.openai]\n"
'api_key = "sk-test"\n'
)
migrate({"mcp_servers": {"a": {"command": "x"}}}, codex_home=tmp_path)
new_text = target.read_text()
# User's codex config preserved
assert "[model]" in new_text
assert 'profile = "default"' in new_text
assert "[providers.openai]" in new_text
# And new MCP block appended
assert "[mcp_servers.a]" in new_text
assert MIGRATION_MARKER in new_text
def test_skipped_keys_reported(self, tmp_path):
report = migrate({
"mcp_servers": {
"x": {
"command": "y",
"sampling": {"enabled": True}, # codex has no equivalent
}
}
}, codex_home=tmp_path)
assert "x" in report.skipped_keys_per_server
assert any("sampling" in s for s in report.skipped_keys_per_server["x"])
def test_invalid_mcp_servers_value(self, tmp_path):
report = migrate({"mcp_servers": "notadict"}, codex_home=tmp_path)
assert any("not a dict" in e for e in report.errors)
def test_server_without_transport_skipped_with_error(self, tmp_path):
report = migrate({
"mcp_servers": {"broken": {"description": "no command/url"}}
}, codex_home=tmp_path)
assert "broken" not in report.migrated
assert any("broken" in e for e in report.errors)
def test_summary_reports_migration_count(self, tmp_path):
report = migrate({
"mcp_servers": {"a": {"command": "x"}, "b": {"command": "y"}}
}, codex_home=tmp_path)
summary = report.summary()
assert "Migrated 2 MCP server(s)" in summary
assert "- a" in summary
assert "- b" in summary