Improve tests of entity limits

tests/helpers/test_entity_platform.py

@@ -934,6 +934,54 @@ async def test_entity_limit_per_config_entry_frees_slot_when_disabled(
     assert hass.states.get("test_domain.ent3") is not None
 
 
+@pytest.mark.parametrize(
+    "filler_ids",
+    [
+        pytest.param([], id="below_limit"),
+        pytest.param(["2"], id="at_limit"),
+    ],
+)
+async def test_entity_limit_per_config_entry_allows_enabling_disabled_entity(
+    hass: HomeAssistant,
+    entity_registry: er.EntityRegistry,
+    caplog: pytest.LogCaptureFixture,
+    filler_ids: list[str],
+) -> None:
+    """Test a user can enable a disabled entity regardless of the limit."""
+    config_entry = MockConfigEntry()
+    config_entry.add_to_hass(hass)
+    platform = MockEntityPlatform(hass)
+    platform.config_entry = config_entry
+
+    with patch.object(entity_platform, "MAX_ENABLED_ENTITIES_PER_CONFIG_ENTRY", 1):
+        # Register a disabled-by-default entity; fillers optionally reach the limit
+        await platform.async_add_entities(
+            [
+                MockEntity(
+                    unique_id="1",
+                    name="ent1",
+                    entity_registry_enabled_default=False,
+                ),
+                *(MockEntity(unique_id=uid, name=f"ent{uid}") for uid in filler_ids),
+            ]
+        )
+
+    entity_id = entity_registry.async_get_entity_id("test_domain", "test_platform", "1")
+    assert entity_id is not None
+    assert hass.states.get("test_domain.ent1") is None
+
+    # The user enables the disabled entity
+    entity_registry.async_update_entity(entity_id, disabled_by=None)
+
+    # Re-adding the now-enabled entity, e.g. after a reload, adds it because it is
+    # already registered, even when this pushes the count over the limit
+    with patch.object(entity_platform, "MAX_ENABLED_ENTITIES_PER_CONFIG_ENTRY", 1):
+        await platform.async_add_entities([MockEntity(unique_id="1", name="ent1")])
+
+    assert hass.states.get("test_domain.ent1") is not None
+    assert "Reached the maximum" not in caplog.text
+
+
 async def test_entity_limit_per_config_entry_allows_existing_entities(
     hass: HomeAssistant,
 ) -> None: