feat(preflight): replace SUPPORTED_RUNTIMES static list with adapter discovery

Closes task #123 — last piece of #87 cleanup.

Pre-fix: workspace/preflight.py:11 hardcoded a tuple of "supported"
runtime names (claude-code, codex, ollama, langgraph, etc.). Every
new template repo required a code change in molecule-runtime to be
recognized — direct violation of the universal-runtime principle
(#87) where adapters declare themselves and the runtime stays generic.

Post-fix: discovery-based validation via the same ADAPTER_MODULE env
var that production load paths already consult
(workspace/adapters/__init__.py:get_adapter). Distinguished failure
modes so operator messages are concrete:

  - ADAPTER_MODULE unset → "no adapter installed; set the env var"
  - ADAPTER_MODULE set but module won't import → import error type +
    message
  - module imports but no Adapter class → "convention violation, add
    `Adapter = YourClass`"
  - Adapter.name() raises → caught with operator message
  - Adapter.name() returns non-string → contract violation message
  - Adapter.name() doesn't match config.runtime → drift WARNING (not
    fatal; the adapter wins in production, config.yaml is just
    documentation)

The drift case is the one behavioral change worth calling out: the
prior static-list path would have hard-failed config.runtime values
not in the allowlist. With discovery, an unknown runtime in
config.yaml is just a documentation drift — the adapter that's
actually installed runs regardless. Operator gets a warning naming
both the configured and installed names so they can fix whichever
is stale.

Tests:
  - Replaces the obsolete "static list pass/fail" tests with 6 new
    cases covering each distinguished failure mode, plus a positive
    test for the adapter-matches-config happy path
  - Adds an autouse `_default_langgraph_adapter` fixture that
    pre-installs a fake adapter via sys.modules monkey-patching, so
    existing tests building default WorkspaceConfig (runtime="langgraph")
    inherit a valid adapter without each test setting ADAPTER_MODULE
  - Failure-mode tests opt out of the default fixture via
    @pytest.mark.no_default_adapter (registered in pytest.ini)
  - Sentinel pattern (`_UNSET = object()`) for `name_returns` so None
    is a passable test value (otherwise `is not None` would skip the
    None branch — exact bug the sentinel avoids)

Verification:
  - 22/22 preflight tests pass (was 16; +6 new failure-path tests)
  - 1256/1256 workspace pytest pass (was 1251; +5 net)
  - No production code path other than preflight changed

Source: 2026-04-27 #87 cleanup audit after PR #2154 (wedge extraction).
This change is independent of the cli_executor.py template moves
(task #122) — completes one of the two remaining cleanup items.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This commit is contained in:
Hongming Wang 2026-04-27 00:44:51 -07:00
parent 66b9c04057
commit 7dba700ac3
3 changed files with 261 additions and 28 deletions

View File

@ -1,22 +1,82 @@
"""Startup preflight checks for workspace runtime configs."""
import importlib
import os
from dataclasses import dataclass, field
from pathlib import Path
from config import WorkspaceConfig
SUPPORTED_RUNTIMES = {
"langgraph",
"claude-code",
"codex",
"ollama",
"custom",
"crewai",
"autogen",
"deepagents",
"openclaw",
}
def _validate_runtime_via_adapter(runtime: str) -> tuple[bool, str]:
"""Discover the installed adapter and confirm it matches the
config's `runtime` field. Returns (ok, detail) — detail is the
operator-actionable failure message when ok is False.
Replaces the previous hardcoded SUPPORTED_RUNTIMES allowlist
(claude-code / codex / ollama / langgraph / etc.). The static list
couldn't keep up with new template repos: each new adapter required
a code change in molecule-runtime to be 'supported', a violation of
the universal-runtime principle (#87).
Discovery uses the same ADAPTER_MODULE env var that production load
paths consult (workspace/adapters/__init__.py:get_adapter). The
adapter's static name() string is the source of truth — config.yaml
just labels which one the operator expects, and the check warns on
drift.
Failure modes the function distinguishes (each gets a distinct
operator-facing message so debugging is concrete):
- ADAPTER_MODULE unset "no adapter installed"
- ADAPTER_MODULE set but module won't import → "import failed: …"
- module imports but no Adapter class "Adapter class missing"
- Adapter.name() differs from config.runtime drift warning
"""
adapter_module = os.environ.get("ADAPTER_MODULE", "").strip()
if not adapter_module:
return False, (
"ADAPTER_MODULE env var is unset — no adapter installed in this "
f"image. Workspace declares runtime='{runtime}' but the runtime "
"discovery path can't find any. In a template image this is set "
"in the Dockerfile (ENV ADAPTER_MODULE=adapter); in dev, set it "
"to your local adapter module name."
)
try:
mod = importlib.import_module(adapter_module)
except Exception as exc:
return False, (
f"ADAPTER_MODULE={adapter_module!r} is not importable: "
f"{type(exc).__name__}: {exc}. Check the module path + that its "
"dependencies installed cleanly."
)
adapter_cls = getattr(mod, "Adapter", None)
if adapter_cls is None:
return False, (
f"ADAPTER_MODULE={adapter_module!r} imported, but no `Adapter` "
"class is exported. Add `Adapter = YourAdapterClass` at module "
"scope (convention from BaseAdapter docstring)."
)
try:
adapter_name = adapter_cls.name()
except Exception as exc:
return False, (
f"Adapter.name() raised {type(exc).__name__}: {exc}. The static "
"name() classmethod must return the runtime identifier without "
"side effects."
)
if not isinstance(adapter_name, str) or not adapter_name:
return False, "Adapter.name() must return a non-empty string."
if adapter_name != runtime:
# Drift between config.yaml and the installed adapter is unusual
# but not fatal — the adapter wins (it's what actually runs).
# Operator-facing detail names both so they can fix whichever is
# stale.
return True, (
f"Drift: config.yaml runtime={runtime!r} but installed Adapter "
f"reports name={adapter_name!r}. The adapter wins; update "
"config.yaml to match if the drift is unintended."
)
return True, ""
@dataclass
@ -42,13 +102,28 @@ def run_preflight(config: WorkspaceConfig, config_path: str) -> PreflightReport:
report = PreflightReport()
config_dir = Path(config_path)
if config.runtime not in SUPPORTED_RUNTIMES:
runtime_ok, runtime_detail = _validate_runtime_via_adapter(config.runtime)
if not runtime_ok:
report.failures.append(
PreflightIssue(
severity="fail",
title="Runtime",
detail=f"Unsupported runtime '{config.runtime}'",
fix="Choose one of the supported runtimes or install the matching adapter.",
detail=runtime_detail,
fix=(
"Install the matching adapter (template repo's Dockerfile "
"should set ADAPTER_MODULE) or correct the runtime field in "
"config.yaml."
),
)
)
elif runtime_detail:
# ok=True with a detail = drift warning, not a failure.
report.warnings.append(
PreflightIssue(
severity="warn",
title="Runtime",
detail=runtime_detail,
fix="Update config.yaml runtime to match the installed Adapter.name().",
)
)

View File

@ -21,6 +21,8 @@ addopts =
--cov=.
--cov-report=term-missing
--cov-fail-under=86
markers =
no_default_adapter: opt out of preflight tests' autouse fake-adapter fixture (for tests that exercise the no-adapter / broken-adapter failure paths)
# Coverage omit / report config lives in workspace/.coveragerc — coverage.py
# only reads .coveragerc / setup.cfg / tox.ini / pyproject.toml, NOT
# pytest.ini, so [coverage:*] sections here would be silently ignored.

View File

@ -1,4 +1,8 @@
"""Tests for preflight.py — workspace startup checks."""
import sys
import types
import pytest
from config import A2AConfig, RuntimeConfig, WorkspaceConfig
from preflight import run_preflight, render_preflight_report, PreflightIssue, PreflightReport
@ -19,16 +23,77 @@ def make_config(**overrides):
return base
def test_run_preflight_supported_runtime_passes(tmp_path):
"""A supported runtime with present files should pass cleanly."""
_UNSET = object()
def install_fake_adapter(monkeypatch, name: str = "langgraph", *, raise_on_name: bool = False, no_class: bool = False, name_returns=_UNSET):
"""Install a fake adapter module + ADAPTER_MODULE env var so the
runtime-discovery path in preflight finds it.
Args:
name: what Adapter.name() returns (default "langgraph" so the
base config's runtime field passes the equality check).
raise_on_name: if True, Adapter.name() raises (tests the catch path).
no_class: if True, the module imports but exports no Adapter symbol.
name_returns: override the literal value name() returns. Defaults
to a sentinel so that None is a passable test value
(else `if name_returns is not None` would skip the
None branch exactly the bug this sentinel avoids).
"""
# Each call uses a unique module name so monkeypatch's sys.modules
# restoration doesn't accidentally reuse a prior test's fake when
# the same `name` is requested twice in one test session.
module_name = f"_fake_adapter_{name.replace('-', '_')}_{id(monkeypatch)}"
fake_mod = types.ModuleType(module_name)
if not no_class:
if raise_on_name:
class _Adapter:
@staticmethod
def name():
raise RuntimeError("boom")
elif name_returns is not _UNSET:
class _Adapter:
@staticmethod
def name():
return name_returns
else:
class _Adapter:
@staticmethod
def name():
return name
fake_mod.Adapter = _Adapter
monkeypatch.setitem(sys.modules, module_name, fake_mod)
monkeypatch.setenv("ADAPTER_MODULE", module_name)
@pytest.fixture(autouse=True)
def _default_langgraph_adapter(monkeypatch, request):
"""Pre-install a langgraph adapter so existing tests that build a
default WorkspaceConfig (runtime="langgraph") pass the discovery
check without each test having to set ADAPTER_MODULE manually.
Tests that need to assert a specific failure mode (no adapter, drift,
missing class, etc.) opt out via the `no_default_adapter` marker:
@pytest.mark.no_default_adapter
def test_(monkeypatch):
...
"""
if "no_default_adapter" in request.keywords:
return
install_fake_adapter(monkeypatch, name="langgraph")
def test_run_preflight_with_matching_adapter_passes(tmp_path):
"""When ADAPTER_MODULE points to a module whose Adapter.name()
matches config.runtime, preflight passes cleanly. Default fixture
installs a langgraph adapter; the base config also says langgraph."""
(tmp_path / "system-prompt.md").write_text("Base prompt.")
(tmp_path / "skills").mkdir()
config = make_config(
prompt_files=["system-prompt.md"],
skills=[],
)
config = make_config(prompt_files=["system-prompt.md"], skills=[])
report = run_preflight(config, str(tmp_path))
assert report.ok is True
@ -36,19 +101,110 @@ def test_run_preflight_supported_runtime_passes(tmp_path):
assert report.warnings == []
def test_run_preflight_unsupported_runtime_fails(tmp_path):
"""Unsupported runtimes should fail before startup."""
def test_run_preflight_unsupported_runtime_warns_about_drift(tmp_path):
"""When the runtime requested is not what the installed adapter
reports, preflight returns the drift warning (not failure) the
adapter wins in production. The PRIOR static-list behavior would
have hard-failed here, but the discovery-based check trusts the
adapter and surfaces the mismatch as actionable info."""
(tmp_path / "system-prompt.md").write_text("Base prompt.")
# Default fixture installs Adapter.name() == "langgraph"; flip the
# config to a different name so the drift warning fires.
config = make_config(runtime="not-a-runtime", prompt_files=["system-prompt.md"])
config = make_config(
runtime="not-a-runtime",
prompt_files=["system-prompt.md"],
)
report = run_preflight(config, str(tmp_path))
assert report.ok is True # drift, not fatal
assert any(issue.title == "Runtime" and "Drift" in issue.detail for issue in report.warnings)
@pytest.mark.no_default_adapter
def test_run_preflight_no_adapter_module_fails(tmp_path, monkeypatch):
"""ADAPTER_MODULE unset → no adapter installed → preflight fails
with an operator-actionable message naming the env var."""
monkeypatch.delenv("ADAPTER_MODULE", raising=False)
(tmp_path / "system-prompt.md").write_text("Base prompt.")
config = make_config(prompt_files=["system-prompt.md"])
report = run_preflight(config, str(tmp_path))
assert report.ok is False
assert any(issue.title == "Runtime" for issue in report.failures)
runtime_failures = [i for i in report.failures if i.title == "Runtime"]
assert len(runtime_failures) == 1
assert "ADAPTER_MODULE" in runtime_failures[0].detail
assert "unset" in runtime_failures[0].detail
@pytest.mark.no_default_adapter
def test_run_preflight_adapter_module_unimportable_fails(tmp_path, monkeypatch):
"""ADAPTER_MODULE set to a non-existent module → import error →
preflight fails with the underlying exception type + message."""
monkeypatch.setenv("ADAPTER_MODULE", "this_module_does_not_exist_for_test")
(tmp_path / "system-prompt.md").write_text("Base prompt.")
config = make_config(prompt_files=["system-prompt.md"])
report = run_preflight(config, str(tmp_path))
assert report.ok is False
assert any(
i.title == "Runtime" and "not importable" in i.detail
for i in report.failures
)
@pytest.mark.no_default_adapter
def test_run_preflight_adapter_module_missing_class_fails(tmp_path, monkeypatch):
"""Module imports but doesn't export `Adapter` → fail with the
convention reminder. Pin the convention so a future refactor
that renames the class doesn't silently bypass discovery."""
install_fake_adapter(monkeypatch, name="langgraph", no_class=True)
(tmp_path / "system-prompt.md").write_text("Base prompt.")
config = make_config(prompt_files=["system-prompt.md"])
report = run_preflight(config, str(tmp_path))
assert report.ok is False
assert any(
i.title == "Runtime" and "no `Adapter` class" in i.detail
for i in report.failures
)
@pytest.mark.no_default_adapter
def test_run_preflight_adapter_name_raises_fails(tmp_path, monkeypatch):
"""Adapter.name() throwing must be caught — the static method
must be side-effect-free per BaseAdapter contract."""
install_fake_adapter(monkeypatch, raise_on_name=True)
(tmp_path / "system-prompt.md").write_text("Base prompt.")
config = make_config(prompt_files=["system-prompt.md"])
report = run_preflight(config, str(tmp_path))
assert report.ok is False
assert any(
i.title == "Runtime" and "name() raised" in i.detail
for i in report.failures
)
@pytest.mark.no_default_adapter
def test_run_preflight_adapter_name_non_string_fails(tmp_path, monkeypatch):
"""Adapter.name() returning None / int / etc. must fail — the
runtime identifier is a string by contract and downstream code
assumes that (config matching, log lines, etc.). Use 42 (int) as
the returned value so the assertion is unambiguous; None would
also work but int is more obviously a contract violation."""
install_fake_adapter(monkeypatch, name_returns=42)
(tmp_path / "system-prompt.md").write_text("Base prompt.")
config = make_config(prompt_files=["system-prompt.md"])
report = run_preflight(config, str(tmp_path))
assert report.ok is False
assert any(
i.title == "Runtime" and "non-empty string" in i.detail
for i in report.failures
)
# ---------- required_env checks ----------