Fix for JSON array parsing in multipart/form-data (#1869) (#1872)

Fixes #1869 .



Changes proposed in this pull request:

- Prioritise parsing JSON over splitting array

---------

Co-authored-by: Alex Fechner <alex.fechner@stryker.com>

connexion/uri_parsing.py

@@ -160,10 +160,10 @@ def resolve_form(self, form_data):
             form_data[k] = self._resolve_param_duplicates(
                 form_data[k], encoding, "form"
             )
-            if defn and defn["type"] == "array":
-                form_data[k] = self._split(form_data[k], encoding, "form")
-            elif "contentType" in encoding and all_json([encoding.get("contentType")]):
+            if "contentType" in encoding and all_json([encoding.get("contentType")]):
                 form_data[k] = json.loads(form_data[k])
+            elif defn and defn["type"] == "array":
+                form_data[k] = self._split(form_data[k], encoding, "form")
             form_data[k] = coerce_type(defn, form_data[k], "requestBody", k)
         return form_data
 

tests/fakeapi/hello/__init__.py

@@ -650,6 +650,15 @@ def post_multipart_form(body):
     return x
 
 
+def post_multipart_form_array(body):
+    result = []
+    for x in body["x"]:
+        x["name"] += "-reply"
+        x["age"] += 10
+        result.append(x)
+    return result
+
+
 def apikey_info(apikey, required_scopes=None):
     if apikey == "mykey":
         return {"sub": "admin"}

tests/fixtures/json_validation/openapi.yaml

@@ -117,3 +117,31 @@ paths:
             application/json:
               schema:
                 $ref: "#/components/schemas/X"
+
+
+  /multipart_form_json_array:
+    post:
+      operationId: fakeapi.hello.post_multipart_form_array
+      requestBody:
+        required: true
+        content:
+          multipart/form-data:
+            schema:
+              type: object
+              properties:
+                x:
+                  type: array
+                  items:
+                    $ref: "#/components/schemas/X"
+            encoding:
+              x:
+                contentType: "application/json"
+      responses:
+        200:
+          description: Modified Echo
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  $ref: "#/components/schemas/X"

tests/test_json_validation.py

@@ -128,3 +128,27 @@ def test_multipart_form_json(json_validation_spec_dir, spec, app_class):
     assert res.status_code == 200
     assert res.json()["name"] == "joe-reply"
     assert res.json()["age"] == 30
+
+
+@pytest.mark.parametrize("spec", ["openapi.yaml"])
+def test_multipart_form_json_array(json_validation_spec_dir, spec, app_class):
+    app = build_app_from_fixture(
+        json_validation_spec_dir,
+        app_class=app_class,
+        spec_file=spec,
+        validate_responses=True,
+    )
+    app_client = app.test_client()
+
+    res = app_client.post(
+        "/v1.0/multipart_form_json_array",
+        files={"file": b""},  # Force multipart/form-data content-type
+        data={
+            "x": json.dumps([{"name": "joe", "age": 20}, {"name": "alena", "age": 28}])
+        },
+    )
+    assert res.status_code == 200
+    assert res.json()[0]["name"] == "joe-reply"
+    assert res.json()[0]["age"] == 30
+    assert res.json()[1]["name"] == "alena-reply"
+    assert res.json()[1]["age"] == 38