From 324242bf4eac07c61123299729c5b8c2a1914d13 Mon Sep 17 00:00:00 2001
From: Dima Knivets <knivets@gmail.com>
Date: Sun, 11 Aug 2019 15:39:35 +0300
Subject: [PATCH] Schemas: Map renderers/parsers for request/response
 media-types.

---
 rest_framework/schemas/openapi.py | 34 ++++++++++++++++++++++++++-----
 tests/schemas/test_openapi.py     | 24 ++++++++++++++++++++++
 2 files changed, 53 insertions(+), 5 deletions(-)

diff --git a/rest_framework/schemas/openapi.py b/rest_framework/schemas/openapi.py
index 4fee95439..cd70b9d0c 100644
--- a/rest_framework/schemas/openapi.py
+++ b/rest_framework/schemas/openapi.py
@@ -1,4 +1,5 @@
 import warnings
+from operator import attrgetter
 from urllib.parse import urljoin
 
 from django.core.validators import (
@@ -8,7 +9,7 @@ from django.core.validators import (
 from django.db import models
 from django.utils.encoding import force_str
 
-from rest_framework import exceptions, serializers
+from rest_framework import exceptions, renderers, serializers
 from rest_framework.compat import uritemplate
 from rest_framework.fields import _UnvalidatedField, empty
 
@@ -78,7 +79,9 @@ class SchemaGenerator(BaseSchemaGenerator):
 
 class AutoSchema(ViewInspector):
 
-    content_types = ['application/json']
+    request_media_types = []
+    response_media_types = []
+
     method_mapping = {
         'get': 'Retrieve',
         'post': 'Create',
@@ -336,6 +339,12 @@ class AutoSchema(ViewInspector):
             self._map_min_max(field, content)
             return content
 
+        if isinstance(field, serializers.FileField):
+            return {
+                'type': 'string',
+                'format': 'binary'
+            }
+
         # Simplest cases, default to 'string' type:
         FIELD_CLASS_SCHEMA_TYPE = {
             serializers.BooleanField: 'boolean',
@@ -430,9 +439,20 @@ class AutoSchema(ViewInspector):
         pagination_class = getattr(self.view, 'pagination_class', None)
         if pagination_class:
             return pagination_class()
-
         return None
 
+    def map_parsers(self, path, method):
+        return list(map(attrgetter('media_type'), self.view.parser_classes))
+
+    def map_renderers(self, path, method):
+        media_types = []
+        for renderer in self.view.renderer_classes:
+            # BrowsableAPIRenderer not relevant to OpenAPI spec
+            if renderer == renderers.BrowsableAPIRenderer:
+                continue
+            media_types.append(renderer.media_type)
+        return media_types
+
     def _get_serializer(self, method, path):
         view = self.view
 
@@ -452,6 +472,8 @@ class AutoSchema(ViewInspector):
         if method not in ('PUT', 'PATCH', 'POST'):
             return {}
 
+        self.request_media_types = self.map_parsers(path, method)
+
         serializer = self._get_serializer(path, method)
 
         if not isinstance(serializer, serializers.Serializer):
@@ -469,7 +491,7 @@ class AutoSchema(ViewInspector):
         return {
             'content': {
                 ct: {'schema': content}
-                for ct in self.content_types
+                for ct in self.request_media_types
             }
         }
 
@@ -482,6 +504,8 @@ class AutoSchema(ViewInspector):
                 }
             }
 
+        self.response_media_types = self.map_renderers(path, method)
+
         item_schema = {}
         serializer = self._get_serializer(path, method)
 
@@ -509,7 +533,7 @@ class AutoSchema(ViewInspector):
             '200': {
                 'content': {
                     ct: {'schema': response_schema}
-                    for ct in self.content_types
+                    for ct in self.response_media_types
                 },
                 # description is a mandatory property,
                 # https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#responseObject
diff --git a/tests/schemas/test_openapi.py b/tests/schemas/test_openapi.py
index 508e7dba8..6c9089e05 100644
--- a/tests/schemas/test_openapi.py
+++ b/tests/schemas/test_openapi.py
@@ -339,6 +339,30 @@ class TestOperationIntrospection(TestCase):
             },
         }
 
+    def test_multipart_request_body_generation(self):
+        """Test that a view's delete method generates a proper response body schema."""
+        path = '/{id}/'
+        method = 'POST'
+
+        class ItemSerializer(serializers.Serializer):
+            attachment = serializers.FileField()
+
+        class View(generics.CreateAPIView):
+            serializer_class = ItemSerializer
+
+        view = create_view(
+            View,
+            method,
+            create_request(path),
+        )
+        inspector = AutoSchema()
+        inspector.view = view
+
+        request_body = inspector._get_request_body(path, method)
+        assert 'multipart/form-data' in request_body['content']
+        attachment = request_body['content']['multipart/form-data']['schema']['properties']['attachment']
+        assert attachment['format'] == 'binary'
+
     def test_retrieve_response_body_generation(self):
         """
         Test that a list of properties is returned for retrieve item views.