DM-41049: Allow derived types in ConfigDictField items

.pre-commit-config.yaml

@@ -6,26 +6,26 @@ repos:
       - id: end-of-file-fixer
       - id: trailing-whitespace
   - repo: https://github.com/psf/black
-    rev: 23.12.0
+    rev: 23.12.1
     hooks:
       - id: black
         # It is recommended to specify the latest version of Python
         # supported by your project here, or alternatively use
         # pre-commit's default_language_version, see
         # https://pre-commit.com/#top_level-default_language_version
-        language_version: python3.10
+        language_version: python3.11
   - repo: https://github.com/pycqa/isort
     rev: 5.13.2
     hooks:
       - id: isort
         name: isort (python)
   - repo: https://github.com/PyCQA/flake8
-    rev: 6.1.0
+    rev: 7.0.0
     hooks:
       - id: flake8
   - repo: https://github.com/astral-sh/ruff-pre-commit
     # Ruff version.
-    rev: v0.1.8
+    rev: v0.1.14
     hooks:
       - id: ruff
   - repo: https://github.com/numpy/numpydoc

python/lsst/pex/config/configDictField.py

@@ -72,7 +72,7 @@ def __setitem__(self, k, x, at=None, label="setitem", setHistory=True):
 
         # validate itemtype
         dtype = self._field.itemtype
-        if type(x) is not self._field.itemtype and x != self._field.itemtype:
+        if not isinstance(x, self._field.itemtype) and x != self._field.itemtype:
             msg = "Value {} at key {!r} is of incorrect type {}. Expected type {}".format(
                 x,
                 k,
@@ -89,7 +89,7 @@ def __setitem__(self, k, x, at=None, label="setitem", setHistory=True):
             if x == dtype:
                 self._dict[k] = dtype(__name=name, __at=at, __label=label)
             else:
-                self._dict[k] = dtype(__name=name, __at=at, __label=label, **x._storage)
+                self._dict[k] = type(x)(__name=name, __at=at, __label=label, **x._storage)
             if setHistory:
                 self.history.append(("Added item at key %s" % k, at, label))
         else:

python/lsst/pex/config/dictField.py

@@ -82,8 +82,9 @@ def __init__(self, config, field, value, at, label, setHistory=True):
                 for k in value:
                     # do not set history per-item
                     self.__setitem__(k, value[k], at=at, label=label, setHistory=False)
-            except TypeError:
-                msg = f"Value {value} is of incorrect type {_typeStr(value)}. Mapping type expected."
+            except TypeError as exc:
+                msg = (f"Setting {k} raised an exception:\n{exc}\nPossible cause: "
+                       f"Value {value} is of incorrect type {_typeStr(value)}. Mapping type expected.")
                 raise FieldValidationError(self._field, self._config, msg)
         if setHistory:
             self._history.append((dict(self._dict), at, label))

tests/test_Config.py

@@ -87,9 +87,13 @@ class OuterConfig(InnerConfig, pexConfig.Config):
 
     i = pexConfig.ConfigField("Outer.i", InnerConfig)
 
-    def __init__(self):
-        pexConfig.Config.__init__(self)
-        self.i.f = 5.0
+    # This does not work - it breaks usage as a type even in ConfigField
+    # def __init__(self):
+    #    pexConfig.Config.__init__(self)
+    #     self.i.f = 5.0
+
+    def setDefaults(self):
+        self.i = InnerConfig(f=5.0)
 
     def validate(self):
         pexConfig.Config.validate(self)
@@ -101,6 +105,7 @@ class Complex(pexConfig.Config):
     """A complex config for testing."""
 
     c = pexConfig.ConfigField("an inner config", InnerConfig)
+    d = pexConfig.ConfigDictField[str, InnerConfig](doc="a configdictfield of inner", default={})
     r = pexConfig.ConfigChoiceField(
         "a registry field", typemap=GLOBAL_REGISTRY, default="AAA", optional=False
     )
@@ -120,14 +125,19 @@ def setUp(self):
         self.simple = Simple()
         self.inner = InnerConfig()
         self.outer = OuterConfig()
-        self.comp = Complex()
+        self.comp_kwargs = {
+            "d": {"outer": self.outer},
+        }
+        self.comp = Complex(**self.comp_kwargs)
         self.deprecation = Deprecation()
 
     def tearDown(self):
         del self.simple
         del self.inner
         del self.outer
+        del self.comp_kwargs
         del self.comp
+        del self.deprecation
 
     def testFieldTypeAnnotationRuntime(self):
         # test parsing type annotation for runtime dtype
@@ -341,7 +351,7 @@ def testSave(self):
             roundtrip_path = os.path.join(tmpdir, "roundtrip.test")
             self.comp.save(roundtrip_path)
 
-            roundTrip = Complex()
+            roundTrip = Complex(**self.comp_kwargs)
             roundTrip.load(roundtrip_path)
             self.assertEqual(self.comp.c.f, roundTrip.c.f)
             self.assertEqual(self.comp.r.name, roundTrip.r.name)
@@ -351,7 +361,7 @@ def testSave(self):
             roundtrip_path = os.path.join(tmpdir, "roundtrip_open.test")
             with open(roundtrip_path, "w") as outfile:
                 self.comp.saveToStream(outfile)
-            roundTrip = Complex()
+            roundTrip = Complex(**self.comp_kwargs)
             with open(roundtrip_path) as infile:
                 roundTrip.loadFromStream(infile)
             self.assertEqual(self.comp.c.f, roundTrip.c.f)
@@ -362,7 +372,7 @@ def testSave(self):
             roundtrip_path = os.path.join(tmpdir, "roundtrip_def.test")
             with open(roundtrip_path, "w") as outfile:
                 self.comp.saveToStream(outfile, root="root")
-            roundTrip = Complex()
+            roundTrip = Complex(**self.comp_kwargs)
             with self.assertRaises(NameError):
                 roundTrip.load(roundtrip_path)
             roundTrip.load(roundtrip_path, root="root")
@@ -374,7 +384,7 @@ def testSave(self):
         saved_string += "config.c.f = parameters.value"
         namespace = SimpleNamespace(value=7)
         extraLocals = {"parameters": namespace}
-        roundTrip = Complex()
+        roundTrip = Complex(**self.comp_kwargs)
         roundTrip.loadFromString(saved_string, extraLocals=extraLocals)
         self.assertEqual(namespace.value, roundTrip.c.f)
         self.assertEqual(self.comp.r.name, roundTrip.r.name)
@@ -528,7 +538,7 @@ def testYaml(self):
         self.assertEqual(self.comp.c.f, comp.c.f)
 
     def testCompare(self):
-        comp2 = Complex()
+        comp2 = Complex(**self.comp_kwargs)
         inner2 = InnerConfig()
         simple2 = Simple()
         self.assertTrue(self.comp.compare(comp2))