From 4a79b559d547f0602d632c8bd4b2f1b2344d485b Mon Sep 17 00:00:00 2001
From: Stein Magnus Jodal <stein.magnus@jodal.no>
Date: Mon, 29 Oct 2012 10:31:35 +0100
Subject: [PATCH] Fail if two backends claims to handle the same URI schema

---
 mopidy/core/actor.py     | 3 +++
 tests/core/actor_test.py | 6 ++++++
 2 files changed, 9 insertions(+)

diff --git a/mopidy/core/actor.py b/mopidy/core/actor.py
index e2eeb746..7fdaeb71 100644
--- a/mopidy/core/actor.py
+++ b/mopidy/core/actor.py
@@ -62,4 +62,7 @@ class Backends(list):
         for backend in backends:
             uri_schemes = backend.uri_schemes.get()
             for uri_scheme in uri_schemes:
+                assert uri_scheme not in self.by_uri_scheme, (
+                    'URI scheme %s is already handled by %s'
+                    % (uri_scheme, backend.__class__.__name__))
                 self.by_uri_scheme[uri_scheme] = backend
diff --git a/tests/core/actor_test.py b/tests/core/actor_test.py
index 95639cf8..9feddbd0 100644
--- a/tests/core/actor_test.py
+++ b/tests/core/actor_test.py
@@ -24,3 +24,9 @@ class CoreActorTest(unittest.TestCase):
 
         self.assertIn('dummy1', result)
         self.assertIn('dummy2', result)
+
+    def test_backends_with_colliding_uri_schemes_fails(self):
+        self.backend2.uri_schemes.get.return_value = ['dummy1', 'dummy2']
+        self.assertRaisesRegexp(
+            AssertionError, 'URI scheme dummy1 is already handled by Mock',
+            Core, audio=None, backends=[self.backend1, self.backend2])