Avoid sending empty integration list multiple times during subscribe_bootstrap_integrations (#49181)

tests/test_bootstrap.py

@@ -7,8 +7,10 @@ from unittest.mock import Mock, patch
 import pytest
 
 from homeassistant import bootstrap, core, runner
+from homeassistant.bootstrap import SIGNAL_BOOTSTRAP_INTEGRATONS
 import homeassistant.config as config_util
 from homeassistant.exceptions import HomeAssistantError
+from homeassistant.helpers.dispatcher import async_dispatcher_connect
 import homeassistant.util.dt as dt_util
 
 from tests.common import (
@@ -610,3 +612,60 @@ async def test_setup_safe_mode_if_no_frontend(
     assert hass.config.skip_pip
     assert hass.config.internal_url == "http://192.168.1.100:8123"
     assert hass.config.external_url == "https://abcdef.ui.nabu.casa"
+
+
+@pytest.mark.parametrize("load_registries", [False])
+async def test_empty_integrations_list_is_only_sent_at_the_end_of_bootstrap(hass):
+    """Test empty integrations list is only sent at the end of bootstrap."""
+    order = []
+
+    def gen_domain_setup(domain):
+        async def async_setup(hass, config):
+            order.append(domain)
+            await asyncio.sleep(0.1)
+
+            async def _background_task():
+                await asyncio.sleep(0.2)
+
+            await hass.async_create_task(_background_task())
+            return True
+
+        return async_setup
+
+    mock_integration(
+        hass,
+        MockModule(
+            domain="normal_integration",
+            async_setup=gen_domain_setup("normal_integration"),
+            partial_manifest={"after_dependencies": ["an_after_dep"]},
+        ),
+    )
+    mock_integration(
+        hass,
+        MockModule(
+            domain="an_after_dep",
+            async_setup=gen_domain_setup("an_after_dep"),
+        ),
+    )
+
+    integrations = []
+
+    @core.callback
+    def _bootstrap_integrations(data):
+        integrations.append(data)
+
+    async_dispatcher_connect(
+        hass, SIGNAL_BOOTSTRAP_INTEGRATONS, _bootstrap_integrations
+    )
+    with patch.object(bootstrap, "SLOW_STARTUP_CHECK_INTERVAL", 0.05):
+        await bootstrap._async_set_up_integrations(
+            hass, {"normal_integration": {}, "an_after_dep": {}}
+        )
+
+    assert integrations[0] != {}
+    assert "an_after_dep" in integrations[0]
+    assert integrations[-3] != {}
+    assert integrations[-1] == {}
+
+    assert "normal_integration" in hass.config.components
+    assert order == ["an_after_dep", "normal_integration"]