Allow parser context to be None (#981)

Default parameter of `parser_context` was already set to `None`
but would had always raised an error.

DRF parser allows `parser_context` to be `None` to so brings DJA to
use the same API.

Author: sliverc

CHANGELOG.md

@@ -13,6 +13,7 @@ any parts of the framework not mentioned in the documentation should generally b
 ### Fixed
 
 * Adjusted error messages to correctly use capitial "JSON:API" abbreviation as used in the specification.
+* Avoid error when `parser_context` is `None` while parsing.
 
 ### Changed
 

rest_framework_json_api/parsers.py

@@ -82,7 +82,8 @@ def parse(self, stream, media_type=None, parser_context=None):
             raise ParseError("Received document does not contain primary data")
 
         data = result.get("data")
-        view = parser_context["view"]
+        parser_context = parser_context or {}
+        view = parser_context.get("view")
 
         from rest_framework_json_api.views import RelationshipView
 
@@ -107,6 +108,7 @@ def parse(self, stream, media_type=None, parser_context=None):
             return data
 
         request = parser_context.get("request")
+        method = request and request.method
 
         # Sanity check
         if not isinstance(data, dict):
@@ -115,7 +117,7 @@ def parse(self, stream, media_type=None, parser_context=None):
             )
 
         # Check for inconsistencies
-        if request.method in ("PUT", "POST", "PATCH"):
+        if method in ("PUT", "POST", "PATCH"):
             resource_name = get_resource_name(
                 parser_context, expand_polymorphic_types=True
             )
@@ -138,12 +140,12 @@ def parse(self, stream, media_type=None, parser_context=None):
                             resource_types=", ".join(resource_name),
                         )
                     )
-        if not data.get("id") and request.method in ("PATCH", "PUT"):
+        if not data.get("id") and method in ("PATCH", "PUT"):
             raise ParseError(
                 "The resource identifier object must contain an 'id' member"
             )
 
-        if request.method in ("PATCH", "PUT"):
+        if method in ("PATCH", "PUT"):
             lookup_url_kwarg = getattr(view, "lookup_url_kwarg", None) or getattr(
                 view, "lookup_field", None
             )

tests/test_parsers.py

@@ -15,8 +15,8 @@ def parser(self):
         return JSONParser()
 
     @pytest.fixture
-    def parse(self, parser, parser_context):
-        def parse_wrapper(data):
+    def parse(self, parser):
+        def parse_wrapper(data, parser_context):
             stream = BytesIO(json.dumps(data).encode("utf-8"))
             return parser.parse(stream, None, parser_context)
 
@@ -41,6 +41,7 @@ def test_parse_formats_field_names(
         settings,
         format_field_names,
         parse,
+        parser_context,
     ):
         settings.JSON_API_FORMAT_FIELD_NAMES = format_field_names
 
@@ -59,25 +60,36 @@ def test_parse_formats_field_names(
             }
         }
 
-        result = parse(data)
+        result = parse(data, parser_context)
         assert result == {
             "id": "123",
             "test_attribute": "test-value",
             "test_relationship": {"id": "123", "type": "TestRelationship"},
         }
 
-    def test_parse_extracts_meta(self, parse):
+    def test_parse_extracts_meta(self, parse, parser_context):
         data = {
             "data": {
                 "type": "BasicModel",
             },
             "meta": {"random_key": "random_value"},
         }
 
-        result = parse(data)
+        result = parse(data, parser_context)
         assert result["_meta"] == data["meta"]
 
-    def test_parse_preserves_json_value_field_names(self, settings, parse):
+    def test_parse_with_default_arguments(self, parse):
+        data = {
+            "data": {
+                "type": "BasicModel",
+            },
+        }
+        result = parse(data, None)
+        assert result == {}
+
+    def test_parse_preserves_json_value_field_names(
+        self, settings, parse, parser_context
+    ):
         settings.JSON_API_FORMAT_FIELD_NAMES = "dasherize"
 
         data = {
@@ -87,17 +99,17 @@ def test_parse_preserves_json_value_field_names(self, settings, parse):
             },
         }
 
-        result = parse(data)
+        result = parse(data, parser_context)
         assert result["json_value"] == {"JsonKey": "JsonValue"}
 
-    def test_parse_raises_error_on_empty_data(self, parse):
+    def test_parse_raises_error_on_empty_data(self, parse, parser_context):
         data = []
 
         with pytest.raises(ParseError) as excinfo:
-            parse(data)
+            parse(data, parser_context)
         assert "Received document does not contain primary data" == str(excinfo.value)
 
-    def test_parse_fails_on_list_of_objects(self, parse):
+    def test_parse_fails_on_list_of_objects(self, parse, parser_context):
         data = {
             "data": [
                 {
@@ -108,7 +120,7 @@ def test_parse_fails_on_list_of_objects(self, parse):
         }
 
         with pytest.raises(ParseError) as excinfo:
-            parse(data)
+            parse(data, parser_context)
 
         assert (
             "Received data is not a valid JSON:API Resource Identifier Object"
@@ -124,7 +136,7 @@ def test_parse_fails_when_id_is_missing_on_patch(self, rf, parse, parser_context
         }
 
         with pytest.raises(ParseError) as excinfo:
-            parse(data)
+            parse(data, parser_context)
 
         assert "The resource identifier object must contain an 'id' member" == str(
             excinfo.value