Blueprint.add_route() for instance method

sanic/blueprints.py

@@ -1,4 +1,5 @@
 from collections import defaultdict, namedtuple
+from types import MethodType
 
 from sanic.constants import HTTP_METHODS
 from sanic.views import CompositionView
@@ -121,9 +122,14 @@ class Blueprint:
         if isinstance(handler, CompositionView):
             methods = handler.handlers.keys()
 
+        _handler = handler
+        if isinstance(handler, MethodType):
+            def _handler(*args, **kwargs):
+                return handler(*args, **kwargs)
+
         self.route(uri=uri, methods=methods, host=host,
-                   strict_slashes=strict_slashes)(handler)
-        return handler
+                   strict_slashes=strict_slashes)(_handler)
+        return _handler
 
     def websocket(self, uri, host=None, strict_slashes=False):
         """Create a blueprint websocket route from a decorated function.

tests/test_blueprints.py

@@ -349,3 +349,21 @@ def test_bp_shorthand():
         'Sec-WebSocket-Version': '13'})
     assert response.status == 101
     assert ev.is_set()
+
+
+def test_blueprint_handler_is_instance_method():
+
+    blueprint = Blueprint('test_blueprint_handler_is_instance_method')
+
+    class Foo():
+
+        def handler(self, request):
+            return text('OK')
+
+    foo = Foo()
+    app = Sanic('test_blueprint_handler_is_instance_method')
+    blueprint.add_route(foo.handler, '/get')
+    app.blueprint(blueprint)
+
+    request, response = app.test_client.get('/get')
+    assert response.text == 'OK'