Fix Nested Serializer Validation Error (#10)

Co-authored-by: bedilbek <[email protected]>

Author: paolodamico

README.md

@@ -59,6 +59,19 @@ REST_FRAMEWORK={
 }
 ```
 
+Optionally set additional configuration for the package.
+```python
+EXCEPTIONS_HOG = {
+    "EXCEPTION_REPORTING": "exceptions_hog.handler.exception_reporter",
+    "ENABLE_IN_DEBUG": False,
+    "NESTED_KEY_SEPARATOR": "__",
+}
+```
+
+- `EXCEPTION_REPORTING`: specify a method to call after an exception occurs. Particularly useful to report errors (e.g. through Sentry, NewRelic, ...). Default: `exceptions_hog.handler.exception_reporter`
+- `ENABLE_IN_DEBUG`: whether exceptions-hog should run when `DEBUG = 1`. It's useful to turn this off in debugging to get full error stack traces when developing. Defaut: `False`.
+- `NESTED_KEY_SEPARATOR`: customize the separator used for obtaining the `attr` name if the exception comes from nested objects (e.g. nested serializers). Default: `__`.
+
 ## 📑 Documentation
 
 We're working on more comprehensive documentation. Feel free to open a PR to contribute to this. In the meantime, you will find the most relevant information for this package here.

exceptions_hog/handler.py

@@ -94,8 +94,18 @@ def override_or_return(code: str) -> str:
             # Only one exception, return
             return (codes, None)
         elif isinstance(codes, dict):
-            key = next(iter(codes))  # Get first key
-            code = codes[key] if isinstance(codes[key], str) else codes[key][0]
+            # If object is a dict or nested dict, return the key of the very first error
+            iterating_key = next(iter(codes))  # Get initial key
+            key = iterating_key
+            while isinstance(codes[iterating_key], dict):
+                codes = codes[iterating_key]
+                iterating_key = next(iter(codes))
+                key = f"{key}{api_settings.NESTED_KEY_SEPARATOR}{iterating_key}"
+            code = (
+                codes[iterating_key]
+                if isinstance(codes[iterating_key], str)
+                else codes[iterating_key][0]
+            )
             return (override_or_return(code), key)
         elif isinstance(codes, list):
             return (override_or_return(str(codes[0])), None)
@@ -115,11 +125,10 @@ def _get_detail(exc, exception_key: str = "") -> str:
                 exc.detail
             )  # We do str() to get the actual error string on ErrorDetail instances
         elif isinstance(exc.detail, dict):
-            return str(
-                exc.detail[exception_key][0]
-                if isinstance(exc.detail[exception_key], str)
-                else exc.detail[exception_key][0]
-            )
+            value = exc.detail
+            for key in exception_key.split(api_settings.NESTED_KEY_SEPARATOR):
+                value = value[key]
+            return str(value if isinstance(value, str) else value[0])
         elif isinstance(exc.detail, list) and len(exc.detail) > 0:
             return exc.detail[0]
 

exceptions_hog/settings.py

@@ -8,6 +8,7 @@
 DEFAULTS: Dict = {
     "EXCEPTION_REPORTING": "exceptions_hog.handler.exception_reporter",
     "ENABLE_IN_DEBUG": False,
+    "NESTED_KEY_SEPARATOR": "__",
 }
 
 # List of settings that may be in string import notation.

requirements-test.txt

@@ -4,4 +4,5 @@ isort==5.5.*
 mypy==0.782
 pytest==6.0.*
 pytest-cov==2.10.1
-pytest-django==3.10.*
+pytest-django==3.10.*
+six==1.15.0

test_project/test_app/apps.py

@@ -1,5 +0,0 @@
-from django.apps import AppConfig
-
-
-class TestAppConfig(AppConfig):
-    name = "test_app"

tests/conftest.py

@@ -9,6 +9,7 @@ def pytest_configure():
     from django.conf import settings
 
     settings.configure(
+        SECRET_KEY="#mk0y8q%rh!ieekh5h#39b@a99u3eg$93kc9oq#z1kpzvg+k2_",
         INSTALLED_APPS=[
             "django.contrib.contenttypes",
             "django.contrib.auth",

tests/test_handler.py

@@ -2,6 +2,7 @@
 from django.db.models import ProtectedError
 from django.http import Http404
 from rest_framework import exceptions, status
+from rest_framework.exceptions import ErrorDetail
 
 from exceptions_hog.handler import exception_handler
 from exceptions_hog.settings import api_settings
@@ -73,6 +74,92 @@ def test_validation_error() -> None:
     }
 
 
+def test_validation_error_serializer_field() -> None:
+    response = exception_handler(
+        exceptions.ValidationError(
+            {
+                "phone_number": [
+                    ErrorDetail(string="This field is required.", code="required")
+                ]
+            }
+        )
+    )
+    assert response is not None
+    assert response.status_code == status.HTTP_400_BAD_REQUEST
+    assert response.data == {
+        "type": "validation_error",
+        "code": "required",
+        "detail": "This field is required.",
+        "attr": "phone_number",
+    }
+
+
+def test_validation_error_with_simple_nested_serializer_field() -> None:
+    response = exception_handler(
+        exceptions.ValidationError(
+            {
+                "parent": {
+                    "children_attr": [
+                        ErrorDetail(string="This field is required.", code="required")
+                    ],
+                    "second_children_attr": [
+                        ErrorDetail(
+                            string="This field is also invalid.", code="invalid_too"
+                        )
+                    ],
+                }
+            }
+        )
+    )
+    assert response is not None
+    assert response.status_code == status.HTTP_400_BAD_REQUEST
+    assert response.data == {
+        "type": "validation_error",
+        "code": "required",
+        "detail": "This field is required.",
+        "attr": "parent__children_attr",
+    }
+
+
+def test_validation_error_with_complex_nested_serializer_field() -> None:
+    response = exception_handler(
+        exceptions.ValidationError(
+            {
+                "parent": {
+                    "l1_attr": {
+                        "l2_attr": {
+                            "l3_attr": ErrorDetail(
+                                string="Focus on this error.", code="focus"
+                            ),
+                        },
+                        "l2_attr_2": {
+                            "l3_attr_2": [
+                                ErrorDetail(
+                                    string="This field is also invalid.",
+                                    code="invalid_too",
+                                )
+                            ]
+                        },
+                    },
+                    "l1_attr_2": [
+                        ErrorDetail(
+                            string="This field is also invalid.", code="invalid_too"
+                        )
+                    ],
+                }
+            }
+        )
+    )
+    assert response is not None
+    assert response.status_code == status.HTTP_400_BAD_REQUEST
+    assert response.data == {
+        "type": "validation_error",
+        "code": "focus",
+        "detail": "Focus on this error.",
+        "attr": "parent__l1_attr__l2_attr__l3_attr",
+    }
+
+
 # Django & DRF exceptions