Fix broken SwaggerDict pickling (#15)

Closes #14.

docs/drf_yasg.rst

@@ -57,6 +57,7 @@ drf\_yasg\.openapi
     :members:
     :undoc-members:
     :show-inheritance:
+    :exclude-members: _bare_SwaggerDict
 
 drf\_yasg\.renderers
 ------------------------------

src/drf_yasg/codecs.py

@@ -87,7 +87,7 @@ def generate_swagger_object(self, swagger):
         :rtype: OrderedDict
         """
         swagger.security_definitions = swagger_settings.SECURITY_DEFINITIONS
-        return swagger
+        return swagger.as_odict()
 
 
 class OpenAPICodecJson(_OpenAPICodec):
@@ -146,9 +146,24 @@ def represent_odict(dump, mapping, flow_style=None):  # pragma: no cover
 SaneYamlDumper.add_multi_representer(OrderedDict, SaneYamlDumper.represent_odict)
 
 
+def yaml_sane_dump(data, binary):
+    """Dump the given data dictionary into a sane format:
+
+        * OrderedDicts are dumped as regular mappings instead of non-standard !!odict
+        * multi-line mapping style instead of json-like inline style
+        * list elements are indented into their parents
+
+    :param dict data: the data to be serializers
+    :param bool binary: True to return a utf-8 encoded binary object, False to return a string
+    :return: the serialized YAML
+    :rtype: str,bytes
+    """
+    return yaml.dump(data, Dumper=SaneYamlDumper, default_flow_style=False, encoding='utf-8' if binary else None)
+
+
 class OpenAPICodecYaml(_OpenAPICodec):
     media_type = 'application/yaml'
 
     def _dump_dict(self, spec):
         """Dump ``spec`` into YAML."""
-        return yaml.dump(spec, Dumper=SaneYamlDumper, default_flow_style=False, encoding='utf-8')
+        return yaml_sane_dump(spec, binary=True)

src/drf_yasg/openapi.py

@@ -62,6 +62,13 @@ def make_swagger_name(attribute_name):
     return camelize(attribute_name.rstrip('_'), uppercase_first_letter=False)
 
 
+def _bare_SwaggerDict(cls):
+    assert issubclass(cls, SwaggerDict)
+    result = cls.__new__(cls)
+    OrderedDict.__init__(result)  # no __init__ called for SwaggerDict subclasses!
+    return result
+
+
 class SwaggerDict(OrderedDict):
     """A particular type of OrderedDict, which maps all attribute accesses to dict lookups using
      :func:`.make_swagger_name`. Attribute names starting with ``_`` are set on the object as-is and are not included
@@ -108,11 +115,25 @@ def _insert_extras__(self):
         for attr, val in self._extras__.items():
             setattr(self, attr, val)
 
-    # noinspection PyArgumentList,PyDefaultArgument
-    def __deepcopy__(self, memodict={}):
-        result = OrderedDict(list(self.items()))
-        result.update(copy.deepcopy(result, memodict))
-        return result
+    @staticmethod
+    def _as_odict(obj):
+        if isinstance(obj, dict):
+            result = OrderedDict()
+            for attr, val in obj.items():
+                result[attr] = SwaggerDict._as_odict(val)
+            return result
+        elif isinstance(obj, (list, tuple)):
+            return type(obj)(SwaggerDict._as_odict(elem) for elem in obj)
+
+        return obj
+
+    def as_odict(self):
+        return SwaggerDict._as_odict(self)
+
+    def __reduce__(self):
+        # for pickle supprt; this skips calls to all SwaggerDict __init__ methods and relies
+        # on the already set attributes instead
+        return _bare_SwaggerDict, (type(self),), vars(self), None, iter(self.items())
 
 
 class Contact(SwaggerDict):

testproj/testproj/urls.py

@@ -29,7 +29,10 @@ def plain_view(request):
 urlpatterns = [
     url(r'^swagger(?P<format>.json|.yaml)$', schema_view.without_ui(cache_timeout=0), name='schema-json'),
     url(r'^swagger/$', schema_view.with_ui('swagger', cache_timeout=0), name='schema-swagger-ui'),
-    url(r'^redoc/$', schema_view.with_ui('redoc', cache_timeout=None), name='schema-redoc'),
+    url(r'^redoc/$', schema_view.with_ui('redoc', cache_timeout=0), name='schema-redoc'),
+    url(r'^cached/swagger(?P<format>.json|.yaml)$', schema_view.without_ui(cache_timeout=None), name='schema-json'),
+    url(r'^cached/swagger/$', schema_view.with_ui('swagger', cache_timeout=None), name='schema-swagger-ui'),
+    url(r'^cached/redoc/$', schema_view.with_ui('redoc', cache_timeout=None), name='schema-redoc'),
 
     url(r'^admin/', admin.site.urls),
     url(r'^snippets/', include('snippets.urls')),

tests/conftest.py

@@ -45,8 +45,8 @@ def validate_schema(swagger):
         from flex.core import parse as validate_flex
         from swagger_spec_validator.validator20 import validate_spec as validate_ssv
 
-        validate_flex(swagger)
-        validate_ssv(swagger)
+        validate_flex(copy.deepcopy(swagger))
+        validate_ssv(copy.deepcopy(swagger))
 
     return validate_schema
 

tests/test_schema_views.py

@@ -1,4 +1,5 @@
 import json
+from collections import OrderedDict
 
 import pytest
 from ruamel import yaml
@@ -46,6 +47,26 @@ def test_redoc(client, validate_schema):
     _validate_text_schema_view(client, validate_schema, '/redoc/?format=openapi', json.loads)
 
 
+def test_caching(client, validate_schema):
+    prev_schema = None
+
+    for i in range(3):
+        _validate_ui_schema_view(client, '/cached/redoc/', 'redoc/redoc.min.js')
+        _validate_text_schema_view(client, validate_schema, '/cached/redoc/?format=openapi', json.loads)
+        _validate_ui_schema_view(client, '/cached/swagger/', 'swagger-ui-dist/swagger-ui-bundle.js')
+        _validate_text_schema_view(client, validate_schema, '/cached/swagger/?format=openapi', json.loads)
+
+        json_schema = client.get('/cached/swagger.json')
+        assert json_schema.status_code == 200
+        json_schema = json.loads(json_schema.content.decode('utf-8'), object_pairs_hook=OrderedDict)
+        if prev_schema is None:
+            validate_schema(json_schema)
+            prev_schema = json_schema
+        else:
+            from datadiff.tools import assert_equal
+            assert_equal(prev_schema, json_schema)
+
+
 @pytest.mark.urls('urlconfs.non_public_urls')
 def test_non_public(client):
     response = client.get('/private/swagger.yaml')