fix(groups): sort groups by unique_key to ensure stable group naming

inputremapper/groups.py

@@ -376,9 +376,10 @@ def run(self):
         #   device breaks autoloading. Sorting fixes it.
         # With sorting, mouse1 always gets group.key "Mouse", and mouse2 always
         # "Mouse 2" (Unless only mouse2 is plugged in, then it gets "Mouse")
+        devices = []
         for path in sorted(evdev.list_devices()):
             try:
-                device = evdev.InputDevice(path)
+                devices.append(evdev.InputDevice(path))
             except Exception as error:
                 # Observed exceptions in journalctl:
                 # - "SystemError: <built-in function ioctl_EVIOCGVERSION> returned NULL
@@ -391,8 +392,14 @@ def run(self):
                     error.__class__.__name__,
                     str(error),
                 )
-                continue
 
+        # Sorting the devices by unique_key (which includes product/vendor/physical port topology)
+        # is extremely important if two identical devices are connected. Without sorting, the order
+        # depends on the order of plugging devices in, causing active injections to swap keys
+        # or break autoloading. Tying the order deterministically to physical ports/IDs fixes this.
+        devices.sort(key=get_unique_key)
+
+        for device in devices:
             if device.name == "Power Button":
                 continue
 
@@ -429,16 +436,17 @@ def run(self):
                 'Found %s "%s" at "%s", hash "%s", key "%s"',
                 device_type.value,
                 device.name,
-                path,
+                device.path,
                 get_device_hash(device),
                 key,
             )
 
-            grouped[key].append((device.name, path, device_type))
+            grouped[key].append((device.name, device.path, device_type))
 
         # now write down all the paths of that group
         result = []
         used_keys = set()
+
         for group in grouped.values():
             names = [entry[0] for entry in group]
             devs = [entry[1] for entry in group]

tests/unit/test_controller.py

@@ -135,7 +135,7 @@ def f(groups):
         self.message_broker.subscribe(MessageType.groups, f)
         self.message_broker.signal(MessageType.init)
         self.assertEqual(
-            ["Foo Device", "Foo Device 2", "Bar Device", "gamepad", "Qux/[Device]?"],
+            ["Foo Device", "Foo Device 2", "Bar Device", "Qux/[Device]?", "gamepad"],
             list(calls[-1].groups.keys()),
         )
 

tests/unit/test_groups.py

@@ -33,7 +33,7 @@
     _Group,
     is_inputremapper_device,
 )
-from tests.lib.fixtures import fixtures, keyboard_keys, Fixture
+from tests.lib.fixtures import fixtures, keyboard_keys
 from tests.lib.test_setup import test_setup
 
 
@@ -115,6 +115,14 @@ def test_find_groups(self):
                         "key": "Bar Device",
                     }
                 ),
+                json.dumps(
+                    {
+                        "paths": ["/dev/input/event52"],
+                        "names": ["Qux/[Device]?"],
+                        "types": [DeviceType.KEYBOARD],
+                        "key": "Qux/[Device]?",
+                    }
+                ),
                 json.dumps(
                     {
                         "paths": [
@@ -129,14 +137,6 @@ def test_find_groups(self):
                         "key": "gamepad",
                     }
                 ),
-                json.dumps(
-                    {
-                        "paths": ["/dev/input/event52"],
-                        "names": ["Qux/[Device]?"],
-                        "types": [DeviceType.KEYBOARD],
-                        "key": "Qux/[Device]?",
-                    }
-                ),
             ]
         )
 
@@ -152,8 +152,8 @@ def test_list_group_names(self):
                 "Foo Device",
                 "Foo Device",
                 "Bar Device",
-                "gamepad",
                 "Qux/[Device]?",
+                "gamepad",
             ],
         )
 

tests/unit/test_reader.py

@@ -916,6 +916,14 @@ def test_are_new_groups_available(self):
                             "key": "Bar Device",
                         }
                     ),
+                    json.dumps(
+                        {
+                            "paths": ["/dev/input/event52"],
+                            "names": ["Qux/[Device]?"],
+                            "types": [DeviceType.KEYBOARD],
+                            "key": "Qux/[Device]?",
+                        }
+                    ),
                     json.dumps(
                         {
                             "paths": [
@@ -930,14 +938,6 @@ def test_are_new_groups_available(self):
                             "key": "gamepad",
                         }
                     ),
-                    json.dumps(
-                        {
-                            "paths": ["/dev/input/event52"],
-                            "names": ["Qux/[Device]?"],
-                            "types": [DeviceType.KEYBOARD],
-                            "key": "Qux/[Device]?",
-                        }
-                    ),
                 ]
             ),
         )