From 165419f227d39b6a8b8ffd4b4ec7a68be400aecb Mon Sep 17 00:00:00 2001
From: Diogo Gomes <dgomes@ua.pt>
Date: Fri, 31 Jul 2026 09:42:43 +0100
Subject: [PATCH] fix empty selector in Integral config flow (#177681)

---
 .../components/integration/config_flow.py     |  4 ++
 .../integration/test_config_flow.py           | 37 +++++++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/homeassistant/components/integration/config_flow.py b/homeassistant/components/integration/config_flow.py
index 718fee7893c5..e4361b6d9d39 100644
--- a/homeassistant/components/integration/config_flow.py
+++ b/homeassistant/components/integration/config_flow.py
@@ -61,6 +61,10 @@ def entity_selector_compatible(
         if current
         else None
     )
+    if unit_of_measurement is None:
+        return selector.EntitySelector(
+            selector.EntitySelectorConfig(domain=ALLOWED_DOMAINS)
+        )
 
     entities = [
         ent.entity_id
diff --git a/tests/components/integration/test_config_flow.py b/tests/components/integration/test_config_flow.py
index 37b0760dc039..d8757ac25c67 100644
--- a/tests/components/integration/test_config_flow.py
+++ b/tests/components/integration/test_config_flow.py
@@ -6,6 +6,7 @@ import pytest
 
 from homeassistant import config_entries
 from homeassistant.components.integration.const import DOMAIN
+from homeassistant.const import UnitOfPower
 from homeassistant.core import HomeAssistant
 from homeassistant.data_entry_flow import FlowResultType
 from homeassistant.helpers import selector
@@ -151,3 +152,39 @@ async def test_options(hass: HomeAssistant, platform) -> None:
     state = hass.states.get(f"{platform}.my_integration")
     assert state.state != "unknown"
     assert state.attributes["unit_of_measurement"] == "kdogmin"
+
+
+async def test_options_source_selector_with_missing_source_unit(
+    hass: HomeAssistant,
+) -> None:
+    """Test reconfiguring when the current source unit is missing."""
+    config_entry = MockConfigEntry(
+        data={},
+        domain=DOMAIN,
+        options={
+            "method": "left",
+            "name": "My integration",
+            "round": 1.0,
+            "source": "sensor.input",
+            "unit_prefix": "k",
+            "unit_time": "min",
+        },
+        title="My integration",
+    )
+    config_entry.add_to_hass(hass)
+    assert await hass.config_entries.async_setup(config_entry.entry_id)
+    await hass.async_block_till_done()
+
+    hass.states.async_set("sensor.input", "unavailable")
+    hass.states.async_set(
+        "sensor.valid_power", 10, {"unit_of_measurement": UnitOfPower.WATT}
+    )
+
+    result = await hass.config_entries.options.async_init(config_entry.entry_id)
+    assert result["type"] is FlowResultType.FORM
+    assert result["step_id"] == "init"
+
+    source = result["data_schema"].schema["source"]
+    assert isinstance(source, selector.EntitySelector)
+    assert source.config["domain"] == ["counter", "input_number", "sensor"]
+    assert "include_entities" not in source.config