From 44973125c15304b4262c51c78b5a86bd1daafa86 Mon Sep 17 00:00:00 2001
From: Ashley Sommer <ashleysommer@gmail.com>
Date: Thu, 14 May 2020 09:54:47 +1000
Subject: [PATCH] Reverse named_response_middlware execution order, to match
 normal response middleware execution order. Fixes #1847 Adds a test to ensure
 fix is correct Adds an example which demonstrates correct blueprint-middlware
 execution order behavior.

---
 .../blueprint_middlware_execution_order.py    | 43 +++++++++++++++++++
 sanic/app.py                                  |  2 +-
 tests/test_blueprints.py                      | 34 ++++++++++++++-
 3 files changed, 77 insertions(+), 2 deletions(-)
 create mode 100644 examples/blueprint_middlware_execution_order.py

diff --git a/examples/blueprint_middlware_execution_order.py b/examples/blueprint_middlware_execution_order.py
new file mode 100644
index 00000000..38fc4cb1
--- /dev/null
+++ b/examples/blueprint_middlware_execution_order.py
@@ -0,0 +1,43 @@
+from sanic import Sanic, Blueprint
+from sanic.response import text
+'''
+Demonstrates that blueprint request middleware are executed in the order they 
+are added. And blueprint response middleware are executed in _reverse_ order.
+On a valid request, it should print "1 2 3 6 5 4" to terminal
+'''
+
+app = Sanic(__name__)
+
+bp = Blueprint("bp_"+__name__)
+
+@bp.middleware('request')
+def request_middleware_1(request):
+    print('1')
+
+@bp.middleware('request')
+def request_middleware_2(request):
+    print('2')
+
+@bp.middleware('request')
+def request_middleware_3(request):
+    print('3')
+
+@bp.middleware('response')
+def resp_middleware_4(request, response):
+    print('4')
+
+@bp.middleware('response')
+def resp_middleware_5(request, response):
+    print('5')
+
+@bp.middleware('response')
+def resp_middleware_6(request, response):
+    print('6')
+
+@bp.route('/')
+def pop_handler(request):
+    return text('hello world')
+
+app.blueprint(bp, url_prefix='/bp')
+
+app.run(host="0.0.0.0", port=8000, debug=True, auto_reload=False)
diff --git a/sanic/app.py b/sanic/app.py
index 6d7f2daf..7ef1c942 100644
--- a/sanic/app.py
+++ b/sanic/app.py
@@ -653,7 +653,7 @@ class Sanic:
                 if _rn not in self.named_response_middleware:
                     self.named_response_middleware[_rn] = deque()
                 if middleware not in self.named_response_middleware[_rn]:
-                    self.named_response_middleware[_rn].append(middleware)
+                    self.named_response_middleware[_rn].appendleft(middleware)
 
     # Decorator
     def middleware(self, middleware_or_request):
diff --git a/tests/test_blueprints.py b/tests/test_blueprints.py
index 47b2b907..69a2118a 100644
--- a/tests/test_blueprints.py
+++ b/tests/test_blueprints.py
@@ -253,7 +253,7 @@ def test_several_bp_with_host(app):
 
 
 def test_bp_middleware(app):
-    blueprint = Blueprint("test_middleware")
+    blueprint = Blueprint("test_bp_middleware")
 
     @blueprint.middleware("response")
     async def process_response(request, response):
@@ -270,6 +270,38 @@ def test_bp_middleware(app):
     assert response.status == 200
     assert response.text == "FAIL"
 
+def test_bp_middleware_order(app):
+    blueprint = Blueprint("test_bp_middleware_order")
+    order = list()
+    @blueprint.middleware("request")
+    def mw_1(request):
+        order.append(1)
+    @blueprint.middleware("request")
+    def mw_2(request):
+        order.append(2)
+    @blueprint.middleware("request")
+    def mw_3(request):
+        order.append(3)
+    @blueprint.middleware("response")
+    def mw_4(request, response):
+        order.append(6)
+    @blueprint.middleware("response")
+    def mw_5(request, response):
+        order.append(5)
+    @blueprint.middleware("response")
+    def mw_6(request, response):
+        order.append(4)
+
+    @blueprint.route("/")
+    def process_response(request):
+        return text("OK")
+
+    app.blueprint(blueprint)
+    order.clear()
+    request, response = app.test_client.get("/")
+
+    assert response.status == 200
+    assert order == [1, 2, 3, 4, 5, 6]
 
 def test_bp_exception_handler(app):
     blueprint = Blueprint("test_middleware")