🚧 WIP

tests/test_read_cli.py

@@ -121,6 +121,186 @@ def test_read_error_tag_reports_error_not_crash(
     assert "0xC0040008" in captured.out
 
 
+# --------------------------------------------------------------------------- #
+# per-tag error rendering (_per_tag_error) — no COM needed
+# --------------------------------------------------------------------------- #
+
+
+def _fake_com_error(hresult: int) -> Exception:
+    """A stand-in with the pywin32 com_error shape for the hresult check."""
+    err = Exception("server rejected the call")
+    err.hresult = hresult  # type: ignore[attr-defined]
+    return err
+
+
+def test_per_tag_error_keeps_hresult_for_com_errors() -> None:
+    from opcda_diagnozer.opc.automation import _per_tag_error
+
+    rendered = _per_tag_error("cannot add tag 'X'", _fake_com_error(0x80020009))
+    assert "cannot add tag 'X'" in rendered
+    assert "HRESULT 0x80020009" in rendered  # decoded COM suffix preserved
+
+
+def test_per_tag_error_names_plain_exceptions() -> None:
+    """A plain ValueError must show its type+text, not a bare 'failed'."""
+    from opcda_diagnozer.opc.automation import _per_tag_error
+
+    rendered = _per_tag_error("read of tag 'X' failed", ValueError("tz math broke"))
+    assert "read of tag 'X' failed" in rendered
+    assert "ValueError" in rendered
+    assert "tz math broke" in rendered
+    assert "HRESULT" not in rendered  # never fake a COM suffix for non-COM errors
+
+
+def test_timestamp_failure_never_fails_a_read() -> None:
+    """A degenerate device timestamp is metadata: value/quality stay readable.
+
+    Reproduces the alias-tag failure shape end-to-end through the adapter's
+    read() with a stubbed COM item: a TimeStamp whose astimezone() explodes
+    (zero FILETIME 1601 / DST math on Matrikon aliases) must yield a GOOD
+    result with device_time=None — never a per-tag error.
+    """
+    from datetime import timezone as _tz
+
+    from opcda_diagnozer.opc import automation
+    from opcda_diagnozer.opc.base import OPCDataSource
+
+    class _PoisonedItem:
+        """A COM item stand-in: reads succeed, TimeStamp cannot be normalized."""
+
+        ItemID = "P5002.Connected"
+
+        def __init__(self) -> None:
+            self.read_calls: list[int] = []
+
+        def Read(self, source: int) -> None:
+            self.read_calls.append(source)
+
+        @property
+        def Value(self):
+            return 1
+
+        @property
+        def Quality(self):
+            return 0xC0
+
+        @property
+        def TimeStamp(self):
+            class _Bad:
+                def astimezone(self, tz):
+                    raise ValueError("astimezone() cannot be applied to a naive datetime")
+
+            return _Bad()
+
+    class _Items:
+        def AddItem(self, item_id: str, handle: int):
+            assert item_id == "P5002.Connected"
+            return _PoisonedItem()
+
+    class _Group:
+        OPCItems = _Items()
+
+        class _Parent:
+            OPCGroups = None  # set below
+
+        Parent = _Parent()
+
+    class _Groups:
+        def Add(self, name: str):
+            return _Group()
+
+    class _Opc:  # minimal stand-in for the wrapper's dispatch object
+        OPCGroups = _Groups()
+
+    class _ClientStub(automation.AutomationOpcClient):
+        def __init__(self) -> None:
+            super().__init__(server="stub")
+            self._opc = _Opc()  # read() requires a connected-looking client
+
+        def _release_and_uninit(self) -> None:  # no COM to release on the stub
+            self._opc = None
+
+    client = _ClientStub()
+    results = client.read(["P5002.Connected"], source=OPCDataSource.DEVICE)
+    assert len(results) == 1
+    result = results[0]
+    assert result.error is None  # the poison never surfaced
+    assert result.value == 1
+    assert result.quality_raw == 0xC0
+    assert result.device_time is None  # metadata dropped, not the read
+
+
+def test_timestamp_property_explosion_never_fails_a_read() -> None:
+    """The frozen-exe failure shape: the TimeStamp PROPERTY itself explodes.
+
+    Missing win32timezone made pywin32 raise SystemError('InvokeTypes ...
+    exception set') when *accessing* item.TimeStamp (not in astimezone) — the
+    guard must therefore wrap the property fetch too, and the read must still
+    return the value/quality.
+    """
+    from opcda_diagnozer.opc import automation
+    from opcda_diagnozer.opc.base import OPCDataSource
+
+    class _ExplodingTsItem:
+        ItemID = "Bucket Brigade.Int1"
+
+        def Read(self, source: int) -> None:
+            return None
+
+        @property
+        def Value(self):
+            return 42
+
+        @property
+        def Quality(self):
+            return 0xC0
+
+        @property
+        def TimeStamp(self):
+            # the exact frozen-exe signature: a non-COM SystemError raised by
+            # pywin32's conversion inside the property access
+            raise SystemError(
+                "<built-in method InvokeTypes of PyIDispatch object> "
+                "returned a result with an exception set"
+            )
+
+    class _Items:
+        def AddItem(self, item_id: str, handle: int):
+            return _ExplodingTsItem()
+
+    class _Group:
+        OPCItems = _Items()
+
+        class _Parent:
+            OPCGroups = None
+
+        Parent = _Parent()
+
+    class _Groups:
+        def Add(self, name: str):
+            return _Group()
+
+    class _Opc:
+        OPCGroups = _Groups()
+
+    class _ClientStub(automation.AutomationOpcClient):
+        def __init__(self) -> None:
+            super().__init__(server="stub")
+            self._opc = _Opc()
+
+        def _release_and_uninit(self) -> None:
+            self._opc = None
+
+    client = _ClientStub()
+    results = client.read(["Bucket Brigade.Int1"], source=OPCDataSource.DEVICE)
+    assert len(results) == 1
+    result = results[0]
+    assert result.error is None  # the timestamp explosion never surfaced
+    assert result.value == 42
+    assert result.quality_raw == 0xC0
+    assert result.device_time is None
+
+
 def test_probe_reads_config_tags(monkeypatch: pytest.MonkeyPatch, tmp_path: Path, capsys) -> None:
     code, fake = _run_cli(monkeypatch, tmp_path, [
         "probe", "-c", str(tmp_path / "config.yaml"),