Django error formatter

ariadne/contrib/django/constants.py

@@ -0,0 +1,19 @@
+FORMATTED_ERROR_MESSAGES: dict = {
+    "ValidationError": {"short": "Invalid input", "details": None,},
+    "ObjectDoesNotExist": {
+        "short": "Not found",
+        "details": "We were unable to locate the resource you requested.",
+    },
+    "NotAuthenticated": {
+        "short": "Unauthorized",
+        "details": "You are not currently authorized to make this request.",
+    },
+    "PermissionDenied": {
+        "short": "Forbidden",
+        "details": "You do not have permission to perform this action.",
+    },
+    "MultipleObjectsReturned": {
+        "short": "Multiple found",
+        "details": "Multiple resources were returned when only a single resource was expected",
+    },
+}

ariadne/contrib/django/format_error.py

@@ -0,0 +1,114 @@
+import sys
+
+import django.core.exceptions
+from graphql import GraphQLError
+
+try:
+    import rest_framework.exceptions
+except ImportError:
+    pass
+
+from ariadne import get_error_extension
+from ariadne.contrib.django.constants import FORMATTED_ERROR_MESSAGES
+
+
+def format_graphql_error(
+    error: GraphQLError,
+    error_field_name: str = "state",
+    constants: dict = None,
+    debug: bool = False,
+) -> dict:
+    """
+    We do not want to render arcane for-developer-only errors in the same way
+    we render user facing errors.  So, we should use a custom field for
+    user-feedback related errors.  We will well established patterns and
+    practices used by ValidationError in core django and django rest framework.
+    Any non-form errors will also be rendered in non_field_errors.
+    """
+    if constants is None:
+        constants = FORMATTED_ERROR_MESSAGES
+
+    rest_framework_enabled = is_rest_framework_enabled()
+
+    formatted = error.formatted
+    original_error = extract_original_error(error)
+
+    if isinstance(original_error, django.core.exceptions.ValidationError):
+        formatted["message"] = constants["ValidationError"]["short"]
+        formatted[error_field_name] = get_full_django_validation_error_details(
+            original_error
+        )
+
+    elif rest_framework_enabled and isinstance(
+        original_error, rest_framework.exceptions.ValidationError
+    ):
+        formatted["message"] = constants["ValidationError"]["short"]
+        formatted[error_field_name] = original_error.get_full_details()
+
+    elif isinstance(original_error, django.core.exceptions.ObjectDoesNotExist):
+        formatted["message"] = constants["ObjectDoesNotExist"]["short"]
+        formatted.setdefault(error_field_name, {})
+        formatted[error_field_name].setdefault("non_field_errors", [])
+        formatted[error_field_name]["non_field_errors"].append(
+            constants["ObjectDoesNotExist"]["details"]
+        )
+
+    elif rest_framework_enabled and isinstance(
+        original_error, rest_framework.exceptions.NotAuthenticated
+    ):
+        formatted["message"] = constants["NotAuthenticated"]["short"]
+        formatted.setdefault(error_field_name, {})
+        formatted[error_field_name].setdefault("non_field_errors", [])
+        formatted[error_field_name]["non_field_errors"].append(
+            constants["NotAuthenticated"]["details"]
+        )
+
+    elif any(
+        [
+            isinstance(original_error, django.core.exceptions.PermissionDenied),
+            rest_framework_enabled
+            and isinstance(original_error, rest_framework.exceptions.PermissionDenied),
+        ]
+    ):
+        formatted["message"] = constants["PermissionDenied"]["short"]
+        formatted.setdefault(error_field_name, {})
+        formatted[error_field_name].setdefault("non_field_errors", [])
+        formatted[error_field_name]["non_field_errors"].append(
+            constants["PermissionDenied"]["details"]
+        )
+
+    elif isinstance(original_error, django.core.exceptions.MultipleObjectsReturned):
+        formatted["message"] = constants["MultipleObjectsReturned"]["short"]
+        formatted.setdefault(error_field_name, {})
+        formatted[error_field_name].setdefault("non_field_errors", [])
+        formatted[error_field_name]["non_field_errors"].append(
+            constants["MultipleObjectsReturned"]["details"]
+        )
+
+    if debug:
+        formatted.setdefault("extensions", {})
+        formatted["extensions"]["exception"] = get_error_extension(error)
+    return formatted
+
+
+def extract_original_error(error: GraphQLError) -> Exception:
+    # Sometimes, ariadne nests the originally raised error.  So, get to the bottom of it!
+    while getattr(error, "original_error", None):
+        error = getattr(error, "original_error")
+    return error
+
+
+def get_full_django_validation_error_details(
+    error: django.core.exceptions.ValidationError,
+) -> dict:
+    if getattr(error, "message_dict", None) is not None:
+        result = error.message_dict
+    elif getattr(error, "message", None) is not None:
+        result = {"non_field_errors": [error.message]}
+    else:
+        result = {"non_field_errors": error.messages}
+    return result
+
+
+def is_rest_framework_enabled() -> bool:
+    return "rest_framework.exceptions" in sys.modules

requirements-dev.in

@@ -1,6 +1,7 @@
 black
 codecov
 django<2.3
+djangorestframework<3.12.0
 freezegun
 mypy
 opentracing

requirements-dev.txt

@@ -13,10 +13,12 @@ chardet==3.0.4            # via requests
 click==7.0                # via black, pip-tools
 codecov==2.1.7            # via -r requirements-dev.in
 coverage==4.5.4           # via codecov, pytest-cov
-django==2.2.13            # via -r requirements-dev.in
+django==2.2.13            # via -r requirements-dev.in, djangorestframework
+djangorestframework==3.11.0  # via -r requirements-dev.in
 fastdiff==0.2.0           # via snapshottest
 freezegun==0.3.15         # via -r requirements-dev.in
 idna==2.8                 # via requests
+importlib-metadata==1.6.1  # via pluggy, pytest
 isort==4.3.21             # via pylint
 lazy-object-proxy==1.4.3  # via astroid
 mccabe==0.6.1             # via pylint
@@ -45,10 +47,14 @@ snapshottest==0.5.1       # via -r requirements-dev.in
 sqlparse==0.3.0           # via django
 termcolor==1.1.0          # via snapshottest
 toml==0.10.0              # via black, pylint
-typed-ast==1.4.0          # via black, mypy
+typed-ast==1.4.0          # via astroid, black, mypy
 typing-extensions==3.7.4.1  # via mypy
 urllib3==1.25.7           # via requests
 wasmer==0.3.0             # via fastdiff
 wcwidth==0.1.7            # via pytest
 werkzeug==1.0.1           # via -r requirements-dev.in
 wrapt==1.11.2             # via astroid
+zipp==3.1.0               # via importlib-metadata
+
+# The following packages are considered to be unsafe in a requirements file:
+# pip