Add "DECIMAL_CONSTRAINTS" to allow field constraints on "Optional[Decimal]" (#9754)

lazyhope · sydney-runkle · web-flow · commit f024d03b832d · 2024-06-25T14:39:24.000Z
Co-authored-by: Sydney Runkle &lt;54324534+sydney-runkle@users.noreply.github.com&gt;
diff --git a/pydantic/_internal/_known_annotated_metadata.py b/pydantic/_internal/_known_annotated_metadata.py
@@ -38,6 +38,7 @@
 GENERATOR_CONSTRAINTS = {*SEQUENCE_CONSTRAINTS, *STRICT}
 
 FLOAT_CONSTRAINTS = {*NUMERIC_CONSTRAINTS, *STRICT}
+DECIMAL_CONSTRAINTS = {'max_digits', 'decimal_places', *FLOAT_CONSTRAINTS}
 INT_CONSTRAINTS = {*NUMERIC_CONSTRAINTS, *STRICT}
 BOOL_CONSTRAINTS = STRICT
 UUID_CONSTRAINTS = STRICT
@@ -101,6 +102,8 @@
     CONSTRAINTS_TO_ALLOWED_SCHEMAS[constraint].update(('lax-or-strict',))
 for constraint in ENUM_CONSTRAINTS:
     CONSTRAINTS_TO_ALLOWED_SCHEMAS[constraint].update(('enum',))
+for constraint in DECIMAL_CONSTRAINTS:
+    CONSTRAINTS_TO_ALLOWED_SCHEMAS[constraint].update(('decimal',))
 
 
 def add_js_update_schema(s: cs.CoreSchema, f: Callable[[], dict[str, Any]]) -> None:
diff --git a/tests/test_types.py b/tests/test_types.py
@@ -3390,13 +3390,18 @@ class Model(BaseModel):
         ),
     ],
 )
-@pytest.mark.parametrize('mode', ['Field', 'condecimal'])
+@pytest.mark.parametrize('mode', ['Field', 'condecimal', 'optional'])
 def test_decimal_validation(mode, type_args, value, result):
     if mode == 'Field':
 
         class Model(BaseModel):
             foo: Decimal = Field(**type_args)
 
+    elif mode == 'optional':
+
+        class Model(BaseModel):
+            foo: Optional[Decimal] = Field(**type_args)
+
     else:
 
         class Model(BaseModel):
