Fixing issue python-restx#177, regarding file uploads as a list. This…

… accounts for multiple arguments as part of the form and sets the correct "consumes" values so that "multipart/form-data" gets submitted, as with a single file, when a list of files is present.

flask_restx/swagger.py

@@ -504,6 +504,9 @@ def serialize_operation(self, doc, method):
         if all_params and any(p["in"] == "formData" for p in all_params):
             if any(p["type"] == "file" for p in all_params):
                 operation["consumes"] = ["multipart/form-data"]
+            elif any(p["type"] == "array" and p["collectionFormat"] == "multi" for p in all_params
+                     if "collectionFormat" in p):
+                operation["consumes"] = ["multipart/form-data"]
             else:
                 operation["consumes"] = [
                     "application/x-www-form-urlencoded",

tests/test_swagger.py

@@ -791,6 +791,49 @@ def get(self):
         assert "consumes" in op
         assert op["consumes"] == ["multipart/form-data"]
 
+    def test_parser_parameter_in_files_append_only(self, api, client):
+        parser = api.parser()
+        parser.add_argument(
+            "in_files", type=FileStorage, location="files", action="append"
+        )
+
+        @api.route("/with-parser/", endpoint="with-parser")
+        class WithParserResource(restx.Resource):
+            @api.expect(parser)
+            def post(self):
+                return {}
+
+        data = client.get_specs()
+        assert "/with-parser/" in data["paths"]
+
+        path = data["paths"]["/with-parser/"]
+        op = path["post"]
+        assert op["consumes"][0] == "multipart/form-data"
+
+    def test_parser_parameter_in_files_append_multiple_parameters(self, api, client):
+        parser = api.parser()
+        parser.add_argument(
+            "in_files", type=FileStorage, location="files", action="append"
+        )
+        # Ensure that we have a second argument not of type file, and therefore will not have the collectionFormat
+        # attribute
+        parser.add_argument(
+            "arbitrary_arguments", type=str, location="form"
+        )
+
+        @api.route("/with-parser/", endpoint="with-parser")
+        class WithParserResource(restx.Resource):
+            @api.expect(parser)
+            def post(self):
+                return {}
+
+        data = client.get_specs()
+        assert "/with-parser/" in data["paths"]
+
+        path = data["paths"]["/with-parser/"]
+        op = path["post"]
+        assert op["consumes"][0] == "multipart/form-data"
+
     def test_explicit_parameters(self, api, client):
         @api.route("/name/<int:age>/", endpoint="by-name")
         class ByNameResource(restx.Resource):