From 673519f6bff1c5638aa81f0861124e4537993e25 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Sun, 12 Sep 2021 12:07:40 -1000
Subject: [PATCH] Prefer more targeted matchers in USB discovery (#56142)

- If there is a more targeted match it should win discovery
---
 homeassistant/components/usb/__init__.py | 15 +++++++++
 tests/components/usb/test_init.py        | 39 ++++++++++++++++++++++++
 2 files changed, 54 insertions(+)

diff --git a/homeassistant/components/usb/__init__.py b/homeassistant/components/usb/__init__.py
index 13f18216cca..095d72f3ed4 100644
--- a/homeassistant/components/usb/__init__.py
+++ b/homeassistant/components/usb/__init__.py
@@ -161,6 +161,7 @@ class USBDiscovery:
         if device_tuple in self.seen:
             return
         self.seen.add(device_tuple)
+        matched = []
         for matcher in self.usb:
             if "vid" in matcher and device.vid != matcher["vid"]:
                 continue
@@ -178,6 +179,20 @@ class USBDiscovery:
                 device.description, matcher["description"]
             ):
                 continue
+            matched.append(matcher)
+
+        if not matched:
+            return
+
+        sorted_by_most_targeted = sorted(matched, key=lambda item: -len(item))
+        most_matched_fields = len(sorted_by_most_targeted[0])
+
+        for matcher in sorted_by_most_targeted:
+            # If there is a less targeted match, we only
+            # want the most targeted match
+            if len(matcher) < most_matched_fields:
+                break
+
             flow: USBFlow = {
                 "domain": matcher["domain"],
                 "context": {"source": config_entries.SOURCE_USB},
diff --git a/tests/components/usb/test_init.py b/tests/components/usb/test_init.py
index b09dad9ebe4..7d620b45984 100644
--- a/tests/components/usb/test_init.py
+++ b/tests/components/usb/test_init.py
@@ -176,6 +176,45 @@ async def test_discovered_by_websocket_scan_limited_by_description_matcher(
     assert mock_config_flow.mock_calls[0][1][0] == "test1"
 
 
+async def test_most_targeted_matcher_wins(hass, hass_ws_client):
+    """Test that the most targeted matcher is used."""
+    new_usb = [
+        {"domain": "less", "vid": "3039", "pid": "3039"},
+        {"domain": "more", "vid": "3039", "pid": "3039", "description": "*2652*"},
+    ]
+
+    mock_comports = [
+        MagicMock(
+            device=slae_sh_device.device,
+            vid=12345,
+            pid=12345,
+            serial_number=slae_sh_device.serial_number,
+            manufacturer=slae_sh_device.manufacturer,
+            description=slae_sh_device.description,
+        )
+    ]
+
+    with patch("pyudev.Context", side_effect=ImportError), patch(
+        "homeassistant.components.usb.async_get_usb", return_value=new_usb
+    ), patch(
+        "homeassistant.components.usb.comports", return_value=mock_comports
+    ), patch.object(
+        hass.config_entries.flow, "async_init"
+    ) as mock_config_flow:
+        assert await async_setup_component(hass, "usb", {"usb": {}})
+        await hass.async_block_till_done()
+        hass.bus.async_fire(EVENT_HOMEASSISTANT_STARTED)
+        await hass.async_block_till_done()
+        ws_client = await hass_ws_client(hass)
+        await ws_client.send_json({"id": 1, "type": "usb/scan"})
+        response = await ws_client.receive_json()
+        assert response["success"]
+        await hass.async_block_till_done()
+
+    assert len(mock_config_flow.mock_calls) == 1
+    assert mock_config_flow.mock_calls[0][1][0] == "more"
+
+
 async def test_discovered_by_websocket_scan_rejected_by_description_matcher(
     hass, hass_ws_client
 ):