DM-40435: Add fallback check for existence with getDeferred

.pre-commit-config.yaml

@@ -8,7 +8,7 @@ repos:
       - id: end-of-file-fixer
       - id: trailing-whitespace
   - repo: https://github.com/psf/black
-    rev: 23.3.0
+    rev: 23.7.0
     hooks:
       - id: black
         # It is recommended to specify the latest version of Python
@@ -23,6 +23,6 @@ repos:
         name: isort (python)
   - repo: https://github.com/astral-sh/ruff-pre-commit
     # Ruff version.
-    rev: v0.0.277
+    rev: v0.0.285
     hooks:
       - id: ruff

pyproject.toml

@@ -180,9 +180,11 @@ select = [
     "D",  # pydocstyle
 ]
 target-version = "py311"
-extend-select = [
-    "RUF100", # Warn about unused noqa
-]
+# Commented out to suppress "unused noqa" in jenkins which has older ruff not
+# generating E721.
+#extend-select = [
+#    "RUF100", # Warn about unused noqa
+#]
 
 [tool.ruff.per-file-ignores]
 # parserYacc docstrings can not be fixed. Docstrings are used to define grammar.

python/lsst/daf/butler/_butler.py

@@ -1341,9 +1341,14 @@ def getDeferred(
             Raised if no collections were provided.
         """
         if isinstance(datasetRefOrType, DatasetRef):
-            if not self._datastore.knows(datasetRefOrType):
+            # Do the quick check first and if that fails, check for artifact
+            # existence. This is necessary for datastores that are configured
+            # in trust mode where there won't be a record but there will be
+            # a file.
+            if self._datastore.knows(datasetRefOrType) or self._datastore.exists(datasetRefOrType):
+                ref = datasetRefOrType
+            else:
                 raise LookupError(f"Dataset reference {datasetRefOrType} does not exist.")
-            ref = datasetRefOrType
         else:
             ref = self._findDatasetRef(datasetRefOrType, dataId, collections=collections, **kwargs)
         return DeferredDatasetHandle(butler=self, ref=ref, parameters=parameters, storageClass=storageClass)

python/lsst/daf/butler/core/dimensions/_records.py

@@ -146,7 +146,7 @@ class SerializedDimensionRecord(_BaseModelCompat):
     )
 
     # Use strict types to prevent casting
-    record: dict[str, None | StrictFloat | StrictStr | StrictBool | StrictInt | tuple[int, int]] = Field(
+    record: dict[str, None | StrictInt | StrictFloat | StrictStr | StrictBool | tuple[int, int]] = Field(
         ...,
         title="Dimension record keys and values.",
         examples=[
@@ -190,7 +190,9 @@ def direct(
         # This method requires tuples as values of the mapping, but JSON
         # readers will read things in as lists. Be kind and transparently
         # transform to tuples
-        _recItems = {k: v if type(v) != list else tuple(v) for k, v in record.items()}  # type: ignore
+        _recItems = {
+            k: v if type(v) != list else tuple(v) for k, v in record.items()  # type: ignore # noqa: E721
+        }
 
         # Type ignore because the ternary statement seems to confuse mypy
         # based on conflicting inferred types of v.

tests/test_butler.py

@@ -1559,6 +1559,11 @@ def testPruneDatasets(self) -> None:
         for ref in refs:
             butler.put(metric, ref)
 
+        # Confirm we can retrieve deferred.
+        dref1 = butler.getDeferred(ref1)  # known and exists
+        metric1 = dref1.get()
+        self.assertEqual(metric1, metric)
+
         # Test different forms of file availability.
         # Need to be in a state where:
         # - one ref just has registry record.
@@ -1603,6 +1608,14 @@ def testPruneDatasets(self) -> None:
         for ref, exists in exists_many.items():
             self.assertEqual(butler.exists(ref, full_check=False), exists)
 
+        # Get deferred checks for existence before it allows it to be
+        # retrieved.
+        with self.assertRaises(LookupError):
+            butler.getDeferred(ref3)  # not known, file exists
+        dref2 = butler.getDeferred(ref2)  # known but file missing
+        with self.assertRaises(FileNotFoundError):
+            dref2.get()
+
         # Test again with a trusting butler.
         butler._datastore.trustGetRequest = True
         exists_many = butler._exists_many([ref0, ref1, ref2, ref3], full_check=True)
@@ -1611,6 +1624,12 @@ def testPruneDatasets(self) -> None:
         self.assertEqual(exists_many[ref2], DatasetExistence.RECORDED | DatasetExistence.DATASTORE)
         self.assertEqual(exists_many[ref3], DatasetExistence.RECORDED | DatasetExistence._ARTIFACT)
 
+        # When trusting we can get a deferred dataset handle that is not
+        # known but does exist.
+        dref3 = butler.getDeferred(ref3)
+        metric3 = dref3.get()
+        self.assertEqual(metric3, metric)
+
         # Check that per-ref query gives the same answer as many query.
         for ref, exists in exists_many.items():
             self.assertEqual(butler.exists(ref, full_check=True), exists)
@@ -2056,12 +2075,10 @@ def testTransferUuidToUuid(self) -> None:
         self.assertButlerTransfers()
 
     def _enable_trust(self, datastore: Datastore) -> None:
-        if hasattr(datastore, "trustGetRequest"):
-            datastore.trustGetRequest = True
-        elif hasattr(datastore, "datastores"):
-            for this_datastore in datastore.datastores:
-                if hasattr(this_datastore, "trustGetRequest"):
-                    this_datastore.trustGetRequest = True
+        datastores = getattr(datastore, "datastores", [datastore])
+        for this_datastore in datastores:
+            if hasattr(this_datastore, "trustGetRequest"):
+                this_datastore.trustGetRequest = True
 
     def testTransferMissing(self) -> None:
         """Test transfers where datastore records are missing.