From fcf2eb4753d02caf258c5b1473fbb74721a3f489 Mon Sep 17 00:00:00 2001
From: David Baumgold <david@davidbaumgold.com>
Date: Sun, 19 May 2019 11:16:53 -0400
Subject: [PATCH] FakeSignal should stub connect_via method

---
 CHANGES.rst      |  2 ++
 flask/signals.py | 17 ++++++++---------
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/CHANGES.rst b/CHANGES.rst
index 9d95317f..6a179bdf 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -47,6 +47,8 @@ Unreleased
 -   The return value from :meth:`cli.load_dotenv` is more consistent
     with the documentation. It will return ``False`` if python-dotenv is
     not installed, or if the given path isn't a file. :issue:`2937`
+-   Signaling support has a stub for the ``connect_via`` method when
+    the Blinker library is not installed. :pr:`3208`
 
 .. _#2935: https://github.com/pallets/flask/issues/2935
 .. _#2957: https://github.com/pallets/flask/issues/2957
diff --git a/flask/signals.py b/flask/signals.py
index 14d9c619..69da0216 100644
--- a/flask/signals.py
+++ b/flask/signals.py
@@ -32,19 +32,18 @@ except ImportError:
             self.name = name
             self.__doc__ = doc
 
+        def send(self, *args, **kwargs):
+            pass
+
         def _fail(self, *args, **kwargs):
             raise RuntimeError(
-                "signalling support is unavailable "
-                "because the blinker library is "
-                "not installed."
+                "Signalling support is unavailable because the blinker"
+                " library is not installed."
             )
 
-        send = lambda *a, **kw: None
-        connect = (
-            disconnect
-        ) = (
-            has_receivers_for
-        ) = receivers_for = temporarily_connected_to = connected_to = _fail
+        connect = connect_via = connected_to = temporarily_connected_to = _fail
+        disconnect = _fail
+        has_receivers_for = receivers_for = _fail
         del _fail