fix(models): report per-file checksum pins in OnnxEncoder.model_sha256 (#403)

#346 / PR #396 added ModelConfig.file_sha256 so every model file can be
pinned, and registry.pinned_checksums(cfg) merges it with the primary-file
sha256 pin. verify() and pull() use the merged pins, but
OnnxEncoder.model_sha256 still read only cfg.sha256. A model whose primary
file is pinned only through file_sha256 was reported as "unverified", and
that value also keys the embedding cache and the model evidence metadata.

model_sha256 now reports pinned_checksums(cfg).get(cfg.files[0]), falling
back to "unverified". The other cfg.sha256 readers were checked and are
already correct: pinned_checksums() is the merge itself, and the status()
note tests "cfg.sha256 or cfg.file_sha256".

Behaviour for the shipped registry, where nothing is pinned yet, is
unchanged.

Author: kevincostner17

src/freshdata/models/runtime.py

@@ -17,7 +17,14 @@
 import numpy as np
 
 from ._lazy import has_semantic_extra, require_onnxruntime, require_tokenizers
-from .registry import COL_ENCODER_ID, get_config, is_installed, model_dir, verify
+from .registry import (
+    COL_ENCODER_ID,
+    get_config,
+    is_installed,
+    model_dir,
+    pinned_checksums,
+    verify,
+)
 from .types import ModelError
 
 _STUB_ENV = "FRESHDATA_STUB_ENCODER"
@@ -47,7 +54,9 @@ class OnnxEncoder:
     def __init__(self, model_id: str) -> None:
         cfg = get_config(model_id)
         self.model_id = model_id
-        self.model_sha256 = cfg.sha256 or "unverified"
+        # The primary file's pin, whether set via ``sha256`` or ``file_sha256``.
+        primary_pin = pinned_checksums(cfg).get(cfg.files[0]) if cfg.files else None
+        self.model_sha256 = primary_pin or "unverified"
         self.dim = 384
         self._session: Any = None
         self._tokenizer: Any = None

tests/test_models_runtime.py

@@ -2,10 +2,14 @@
 
 from __future__ import annotations
 
+import dataclasses
+import hashlib
+
 import numpy as np
 import pytest
 
 from freshdata.models import ModelError, runtime
+from freshdata.models import registry as reg
 from freshdata.models.stub import StubEncoder
 from freshdata.semantic.cache import EmbeddingCache
 
@@ -123,6 +127,52 @@ def test_embedding_cache_disabled():
     assert len(cache) == 0
 
 
+_FAKE_MODEL = b"FAKE-ONNX-BYTES"
+_FAKE_TOKENIZER = b'{"vocab": []}'
+
+
+def _sha(payload: bytes) -> str:
+    return hashlib.sha256(payload).hexdigest()
+
+
+def test_onnx_encoder_reports_primary_file_pin_from_file_sha256(monkeypatch):
+    # Constructing OnnxEncoder is lazy: no ONNX runtime or model files needed.
+    cfg = dataclasses.replace(
+        reg.get_config(reg.COL_ENCODER_ID),
+        sha256=None,
+        file_sha256=(
+            ("tokenizer.json", _sha(_FAKE_TOKENIZER)),
+            ("model.onnx", _sha(_FAKE_MODEL)),
+        ),
+    )
+    monkeypatch.setitem(reg.REGISTRY, reg.COL_ENCODER_ID, cfg)
+    encoder = runtime.OnnxEncoder(reg.COL_ENCODER_ID)
+    assert encoder.model_sha256 == _sha(_FAKE_MODEL)
+    assert encoder._session is None  # nothing was loaded
+
+
+def test_onnx_encoder_reports_primary_pin_from_sha256(monkeypatch):
+    cfg = dataclasses.replace(
+        reg.get_config(reg.COL_ENCODER_ID),
+        sha256=_sha(_FAKE_MODEL),
+        file_sha256=(("tokenizer.json", _sha(_FAKE_TOKENIZER)),),
+    )
+    monkeypatch.setitem(reg.REGISTRY, reg.COL_ENCODER_ID, cfg)
+    assert runtime.OnnxEncoder(reg.COL_ENCODER_ID).model_sha256 == _sha(_FAKE_MODEL)
+
+
+def test_onnx_encoder_unpinned_reports_unverified(monkeypatch):
+    cfg = dataclasses.replace(reg.get_config(reg.COL_ENCODER_ID), sha256=None, file_sha256=())
+    monkeypatch.setitem(reg.REGISTRY, reg.COL_ENCODER_ID, cfg)
+    assert runtime.OnnxEncoder(reg.COL_ENCODER_ID).model_sha256 == "unverified"
+
+
+def test_onnx_encoder_shipped_registry_reports_unverified():
+    # Today's registry pins nothing, so behaviour is unchanged.
+    for model_id in reg.REGISTRY:
+        assert runtime.OnnxEncoder(model_id).model_sha256 == "unverified"
+
+
 def test_onnx_encoder_requires_extra():
     pytest.importorskip("onnxruntime")
     # With the extra installed but no model files, availability names the pull path.