feat: Improved data validation to handle nested errors and improve type validation

Author: marcusfrdk

tomlval/utils/validate_data.py

@@ -123,6 +123,10 @@ def _validate_wildcard_patterns(self) -> None:
                     )
                     self.applied_keys.add(data_key)
 
+                    if "." in data_key:
+                        parent_key = data_key.split(".")[0]
+                        self.applied_keys.add(parent_key)
+
     def _validate_catch_all(self) -> None:
         """Validate remaining keys with catch-all wildcard '*'."""
         if "*" in self.schema:
@@ -356,6 +360,7 @@ def _validate_mixed_type_element(
     ) -> None:
         """Validate an element against multiple allowed types."""
         valid_type_found = False
+        nested_errors_found = False
         sorted_types = sorted(
             allowed_types, key=lambda t: t == bool, reverse=True
         )
@@ -375,24 +380,33 @@ def _validate_mixed_type_element(
                             break
                     continue
 
+                # For complex types (like dicts), validate and propagate specific errors
                 temp_errors = {}
                 temp_validator = DataValidator(
-                    {key_path: element_value},
-                    {key_path: allowed_type},
+                    element_value,  # Use the element value directly as data
+                    allowed_type,  # Use the allowed type directly as schema
                     temp_errors,
                 )
-                temp_validator.validate_data_value(
-                    key_path, element_value, allowed_type
-                )
+                temp_validator.validate()
 
                 if not temp_errors:
                     valid_type_found = True
                     break
+                else:
+                    # If there are specific validation errors, add them directly
+                    # to our main errors dict with their precise key paths
+                    for error_key, error_code in temp_errors.items():
+                        # Prepend the array element path to create full key path
+                        full_error_key = f"{key_path}.{error_key}"
+                        self.errors[full_error_key] = error_code
+                        nested_errors_found = True
+                    # Don't break here - continue trying other allowed types
 
             except Exception:
                 continue
 
-        if not valid_type_found:
+        # Only add generic error if no valid type was found AND no specific nested errors were found
+        if not valid_type_found and not nested_errors_found:
             self.errors[key_path] = ValidationErrorCode.INVALID_ARRAY_ELEMENT
 
     def _validate_tuple_types(