Add object_to_multipart_dict utility

Taskfile.yml

@@ -66,7 +66,7 @@ tasks:
       # Clear cache files
       rm -rf $PACKAGE_DIR/testing/.pytest_run_cache
       # Run pytest
-      poetry run pytest -n auto
+      poetry run pytest -n auto {{.CLI_ARGS}}
   #============================================================#
   #================= SECTION_HEADING ==========================#
   #============================================================#

django_utils_lib/requests.py

@@ -0,0 +1,41 @@
+from typing import Dict, Optional
+
+
+def object_to_multipart_dict(obj: Dict, existing_multipart_dict: Optional[dict] = None, key_prefix="") -> Dict:
+    """
+    This is basically the inverse of a multi-part form parser, which can additionally
+    handle nested entries.
+
+    The main use-case for this is constructing requests in Python that emulate
+    a multipart FormData payload that would normally be sent by the frontend.
+
+    Nested entries get flattened / hoisted, so that the final dict is a flat
+    key-value map, with bracket notation used for nested entries. List items are
+    also hoisted up, with indices put within leading brackets.
+
+    Warning: values are not stringified (but would be in a true multipart payload)
+
+    @example
+    ```
+    nested_dict = {"a": 1, "multi": [{"id": "abc"}, {"id": "123"}]}
+    print(object_to_multipart_dict(nested_dict))
+    # > {'a': 1, 'multi[0][id]': 'abc', 'multi[1][id]': '123'}
+    ```
+    """
+    result = existing_multipart_dict or {}
+    for _key, val in obj.items():
+        # If this is a nested child, we need to wrap key in brackets
+        _key = f"[{_key}]" if existing_multipart_dict else _key
+        key = key_prefix + _key
+        if isinstance(val, dict):
+            object_to_multipart_dict(val, result, key)
+        elif isinstance(val, (list, tuple)):
+            for i, sub_val in enumerate(val):
+                sub_key = f"{key}[{i}]"
+                if isinstance(sub_val, dict):
+                    object_to_multipart_dict(sub_val, result, sub_key)
+                else:
+                    result[sub_key] = sub_val
+        else:
+            result[key] = val
+    return result

django_utils_lib/testing/pytest_plugin.py

@@ -21,10 +21,10 @@
 import xdist
 import xdist.dsession
 import xdist.workermanage
-from constants import PACKAGE_NAME
 from filelock import FileLock
 from typing_extensions import NotRequired, TypedDict
 
+from django_utils_lib.constants import PACKAGE_NAME
 from django_utils_lib.logger import build_heading_block, pkg_logger
 from django_utils_lib.testing.utils import PytestNodeID, is_main_pytest_runner, validate_requirement_tagging
 

django_utils_lib/tests/test_requests.py

@@ -0,0 +1,22 @@
+from django_utils_lib.requests import object_to_multipart_dict
+
+
+def test_object_to_multipart_dict():
+    regular_dict = {
+        "a": 1,
+        "b": ("tuple_a", "tuple_b"),
+        "c": ["list_a", "list_b"],
+        "nested_dict": {"nested_a_b": {"d": "d test"}, "e": "e test", "f": 24.1},
+        "nested_objs_list": [{"name": "nested obj a"}, {"name": "nested obj b"}],
+    }
+    multipart_dict = object_to_multipart_dict(regular_dict)
+    assert multipart_dict.get("a") == 1
+    assert multipart_dict.get("b[0]") == "tuple_a"
+    assert multipart_dict.get("b[1]") == "tuple_b"
+    assert multipart_dict.get("c[0]") == "list_a"
+    assert multipart_dict.get("c[1]") == "list_b"
+    assert multipart_dict.get("nested_dict[nested_a_b][d]") == "d test"
+    assert multipart_dict.get("nested_dict[e]") == "e test"
+    assert multipart_dict.get("nested_dict[f]") == 24.1
+    assert multipart_dict.get("nested_objs_list[0][name]") == "nested obj a"
+    assert multipart_dict.get("nested_objs_list[1][name]") == "nested obj b"