Files
ha-nvidia-shield/tests/voluptuous_mirror.py
James Mackay 7a0152e6b5 fix(tests): F2 — the voluptuous mirror compares fields, not marker classes (t35)
real voluptuous 0.16.0 implements ``Marker.__eq__`` as ``self.schema ==
other`` — a field-name comparison with no class check, so
``Optional("x") == Required("x")`` is True (verified against the library
source, not just the audit note). The mirror compared class + field, which
kept two dict entries for one field: a ``Required(field, default=...)`` after
``Optional(field)`` LOOKED like it applied the default, while real voluptuous
keeps the first (defaultless) key object and silently drops it — the exact
t33 F-A failure mode the mirror exists to catch, i.e. the harness could mask
the bug it was built to see.

``Marker.__eq__`` is now the library's comparison and the contract tests gained
both pins: field-only equality (with equal hashes) and the mixed-marker
re-declaration that used to be masked. Reverting only ``__eq__`` makes those
two fail, which is the red proof recorded for t35.

Verified: uvx --with pytest-asyncio pytest tests -q → 276 passed, 1 skipped;
uvx ruff check custom_components tests → clean.
2026-10-10 21:04:34 +01:00

95 lines
3.4 KiB
Python

"""A voluptuous mirror faithful enough to SEE a dropped schema default.
The test environment never installs voluptuous (the config-flow tests import
``config_flow`` against import-only stubs), so the harness has to model the two
behaviours the flow schemas depend on:
* ``Optional(field, default=value)`` / ``Required(field, default=value)`` carry
that default on the KEY object;
* keys compare by FIELD NAME only — real ``voluptuous.Marker.__eq__`` is
``self.schema == other`` (no class check at all), so
``Optional("x") == Required("x")`` is True, and ``__hash__`` is
``hash(self.schema)``. A later re-declaration of the same field therefore
collides with the FIRST key object, so a default added by a second
declaration is silently dropped.
That second property is exactly how the t33 F-A discovery-prefill bug hid from
the suite: the old stubs reduced every key to its bare string, so a schema
whose host key carried no default looked identical to one that carried the
discovered address. ``TestVoluptuousMirrorContract`` in
``tests/test_config_flow_ux.py`` pins both properties so the harness itself
cannot regress into blindness.
"""
from __future__ import annotations
UNDEFINED = object()
"""Sentinel for "this key declares no default" (real ``voluptuous.UNDEFINED``)."""
class Marker:
"""Stand-in for ``voluptuous.Marker`` (the ``Required``/``Optional`` base)."""
def __init__(self, schema, default=UNDEFINED):
self.schema = schema
self.default = default
def __hash__(self):
# real Marker hashes the field name only
return hash(self.schema)
def __eq__(self, other):
# real Marker.__eq__ is `self.schema == other`: the FIELD is the whole
# comparison — no class check, so Optional("x") == Required("x") (and
# even Marker("x") == "x") is True. That is what makes a re-declaration
# of a field collide with the first key object and drop its default.
return self.schema == other
def __repr__(self):
return f"<{type(self).__name__} {self.schema!r} default={self.default!r}>"
class Required(Marker):
"""Stand-in for ``voluptuous.Required``."""
class Optional(Marker):
"""Stand-in for ``voluptuous.Optional``."""
def install(vol) -> None:
"""Wire the mirror onto a stub ``voluptuous`` module object."""
vol.UNDEFINED = UNDEFINED
vol.Marker = Marker
vol.Required = Required
vol.Optional = Optional
vol.Schema = lambda schema: schema
def defaults_by_key(schema_dict) -> dict:
"""``{field: default}`` for a schema declared with mirror keys."""
return {key.schema: key.default for key in declared_keys(schema_dict)}
def declared_keys(schema_dict) -> list:
"""The schema's marker keys, in declaration order.
Raises on a non-marker key: a bare string key means the harness (or the
code under test) lost the KEY structure this mirror exists to check.
Test-harness bookkeeping keys (``__suggested__`` and friends) are skipped.
"""
keys = []
for key in schema_dict:
if isinstance(key, Marker):
keys.append(key)
continue
if isinstance(key, str) and key.startswith("__"):
continue
raise AssertionError(f"schema key {key!r} is not a voluptuous marker")
return keys
def declared_fields(schema_dict) -> list:
"""The field names of a schema, in declaration order."""
return [key.schema for key in declared_keys(schema_dict)]