Fix description for array-like fields (#184)

Author: sergue1

src/python-fastui/fastui/json_schema.py

@@ -210,7 +210,7 @@ def json_schema_array_to_fields(
     items_schema = schema.get('items')
     if items_schema:
         items_schema, required = deference_json_schema(items_schema, defs, required)
-        for field_name in 'search_url', 'placeholder':
+        for field_name in 'search_url', 'placeholder', 'description':
             if value := schema.get(field_name):
                 items_schema[field_name] = value  # type: ignore
         if field := special_string_field(items_schema, loc_to_name(loc), title, required, True):
@@ -312,7 +312,7 @@ def deference_json_schema(
         if def_schema is None:
             raise ValueError(f'Invalid $ref "{ref}", not found in {defs}')
         else:
-            return def_schema, required
+            return def_schema.copy(), required  # clone dict to avoid attribute leakage via shared schema.
     elif any_of := schema.get('anyOf'):
         if len(any_of) == 2 and sum(s.get('type') == 'null' for s in any_of) == 1:
             # If anyOf is a single type and null, then it is optional

src/python-fastui/tests/test_forms.py

@@ -1,3 +1,4 @@
+import enum
 from contextlib import asynccontextmanager
 from io import BytesIO
 from typing import List, Tuple, Union
@@ -6,7 +7,7 @@
 from fastapi import HTTPException
 from fastui import components
 from fastui.forms import FormFile, Textarea, fastui_form
-from pydantic import BaseModel
+from pydantic import BaseModel, Field
 from starlette.datastructures import FormData, Headers, UploadFile
 from typing_extensions import Annotated
 
@@ -469,3 +470,55 @@ def test_form_textarea_form_fields():
             }
         ],
     }
+
+
+class SelectEnum(str, enum.Enum):
+    one = 'one'
+    two = 'two'
+
+
+class FormSelectMultiple(BaseModel):
+    select_single: SelectEnum = Field(title='Select Single', description='first field')
+    select_single_2: SelectEnum = Field(title='Select Single')  # unset description to test leakage from prev. field
+    select_multiple: List[SelectEnum] = Field(title='Select Multiple', description='third field')
+
+
+def test_form_description_leakage():
+    m = components.ModelForm(model=FormSelectMultiple, submit_url='/foobar/')
+
+    assert m.model_dump(by_alias=True, exclude_none=True) == {
+        'formFields': [
+            {
+                'description': 'first field',
+                'locked': False,
+                'multiple': False,
+                'name': 'select_single',
+                'options': [{'label': 'One', 'value': 'one'}, {'label': 'Two', 'value': 'two'}],
+                'required': True,
+                'title': ['Select Single'],
+                'type': 'FormFieldSelect',
+            },
+            {
+                'locked': False,
+                'multiple': False,
+                'name': 'select_single_2',
+                'options': [{'label': 'One', 'value': 'one'}, {'label': 'Two', 'value': 'two'}],
+                'required': True,
+                'title': ['Select Single'],
+                'type': 'FormFieldSelect',
+            },
+            {
+                'description': 'third field',
+                'locked': False,
+                'multiple': True,
+                'name': 'select_multiple',
+                'options': [{'label': 'One', 'value': 'one'}, {'label': 'Two', 'value': 'two'}],
+                'required': True,
+                'title': ['Select Multiple'],
+                'type': 'FormFieldSelect',
+            },
+        ],
+        'method': 'POST',
+        'submitUrl': '/foobar/',
+        'type': 'ModelForm',
+    }