Allow "Required: False" on Response headers - Fix #1261 (#1293)

* Add failing test for optional header

* Required: False headers don't give error if missing

* Use dict.get

* Required keys are when they are not present, or present with "True"

* Update connexion/decorators/response.py

Co-authored-by: Ruwann <ruwan.lambrichts@ml6.eu>

* Update tests for required and optional headers

Swagger2 response headers are optional, and have no 'required'
attribute. OpenAPI3 response headers are optional by default,
but can be specified to be required by setting 'required: true'.

* Make headers required for tests that rely on it

Co-authored-by: Ruwann <ruwan.lambrichts@ml6.eu>

connexion/decorators/response.py

@@ -55,9 +55,10 @@ def validate_response(self, data, status_code, headers, url):
                 raise NonConformingResponseBody(message=str(e))
 
         if response_definition and response_definition.get("headers"):
-            response_definition_header_keys = response_definition.get("headers").keys()
-            header_keys = headers.keys()
-            missing_keys = response_definition_header_keys - header_keys
+            required_header_keys = {k for (k, v) in response_definition.get("headers").items()
+                                    if v.get("required", False)}
+            header_keys = set(headers.keys())
+            missing_keys = required_header_keys - header_keys
             if missing_keys:
                 pretty_list = ', '.join(missing_keys)
                 msg = ("Keys in header don't match response specification. "

tests/api/test_headers.py

@@ -17,8 +17,8 @@ def test_headers_produces(simple_app):
     assert response.headers["Location"] == "http://localhost/my/uri"
 
 
-def test_header_not_returned(simple_app):
-    app_client = simple_app.app.test_client()
+def test_header_not_returned(simple_openapi_app):
+    app_client = simple_openapi_app.app.test_client()
 
     response = app_client.post('/v1.0/goodday/noheader', data={})  # type: flask.Response
     assert response.status_code == 500  # view_func has not returned what was promised in spec
@@ -42,3 +42,10 @@ def test_no_content_object_and_have_headers(simple_app):
     resp = app_client.get('/v1.0/test-204-with-headers-nocontent-obj')
     assert resp.status_code == 204
     assert 'X-Something' in resp.headers
+
+
+def test_optional_header(simple_openapi_app):
+    app_client = simple_openapi_app.app.test_client()
+    resp = app_client.get('/v1.0/test-optional-headers')
+    assert resp.status_code == 200
+    assert 'X-Optional-Header' not in resp.headers

tests/fakeapi/hello/__init__.py

@@ -601,3 +601,7 @@ def get_date():
 
 def get_uuid():
     return {'value': uuid.UUID(hex='e7ff66d0-3ec2-4c4e-bed0-6e4723c24c51')}
+
+
+def test_optional_headers():
+    return {}, 200

tests/fixtures/simple/openapi.yaml

@@ -690,6 +690,7 @@ paths:
               description: The URI of the created resource
               schema:
                 type: string
+              required: true
           content:
             'application/json':
               schema:
@@ -714,6 +715,7 @@ paths:
               description: The URI of the created resource
               schema:
                 type: string
+              required: true
           content:
             'application/json':
               schema:
@@ -731,6 +733,7 @@ paths:
               description: The URI of the created resource
               schema:
                 type: string
+              required: true
           content:
             text/plain:
               schema:
@@ -1140,6 +1143,22 @@ paths:
             application/json:
               schema:
                 type: object
+  /test-optional-headers:
+    get:
+      operationId: fakeapi.hello.test_optional_headers
+      responses:
+        '200':
+          description: Some object response
+          content:
+            application/json:
+              schema:
+                type: object
+          headers:
+            X-Optional-Header:
+              description: Optional header
+              schema:
+                type: string
+              required: false
 
 servers:
   - url: http://localhost:{port}/{basePath}

tests/fixtures/simple/swagger.yaml

@@ -556,21 +556,6 @@ paths:
           required: true
           type: string
 
-  /goodday/noheader:
-    post:
-      summary: Generate good day greeting
-      description: Generates a good day message.
-      operationId: fakeapi.hello.post_goodday_no_header
-      responses:
-        201:
-          description: gooday response
-          headers:
-            Location:
-              type: string
-              description: The URI of the created resource
-          schema:
-            type: object
-
   /goodevening/{name}:
     post:
       summary: Generate good evening