Prevent discovered Tradfri while already configured (#16891)

* Prevent discovered Tradfri while already configured

* Lint

tests/components/tradfri/test_init.py

@@ -0,0 +1,72 @@
+"""Tests for Tradfri setup."""
+from unittest.mock import patch
+
+from homeassistant.setup import async_setup_component
+
+from tests.common import MockConfigEntry
+
+
+async def test_config_yaml_host_not_imported(hass):
+    """Test that we don't import a configured host."""
+    MockConfigEntry(
+        domain='tradfri',
+        data={'host': 'mock-host'}
+    ).add_to_hass(hass)
+
+    with patch('homeassistant.components.tradfri.load_json',
+               return_value={}), \
+            patch.object(hass.config_entries.flow, 'async_init') as mock_init:
+        assert await async_setup_component(hass, 'tradfri', {
+            'tradfri': {
+                'host': 'mock-host'
+            }
+        })
+
+    assert len(mock_init.mock_calls) == 0
+
+
+async def test_config_yaml_host_imported(hass):
+    """Test that we import a configured host."""
+    with patch('homeassistant.components.tradfri.load_json',
+               return_value={}):
+        assert await async_setup_component(hass, 'tradfri', {
+            'tradfri': {
+                'host': 'mock-host'
+            }
+        })
+
+    progress = hass.config_entries.flow.async_progress()
+    assert len(progress) == 1
+    assert progress[0]['handler'] == 'tradfri'
+    assert progress[0]['context'] == {'source': 'import'}
+
+
+async def test_config_json_host_not_imported(hass):
+    """Test that we don't import a configured host."""
+    MockConfigEntry(
+        domain='tradfri',
+        data={'host': 'mock-host'}
+    ).add_to_hass(hass)
+
+    with patch('homeassistant.components.tradfri.load_json',
+               return_value={'mock-host': {'key': 'some-info'}}), \
+            patch.object(hass.config_entries.flow, 'async_init') as mock_init:
+        assert await async_setup_component(hass, 'tradfri', {
+            'tradfri': {}
+        })
+
+    assert len(mock_init.mock_calls) == 0
+
+
+async def test_config_json_host_imported(hass):
+    """Test that we import a configured host."""
+    with patch('homeassistant.components.tradfri.load_json',
+               return_value={'mock-host': {'key': 'some-info'}}):
+        assert await async_setup_component(hass, 'tradfri', {
+            'tradfri': {}
+        })
+
+    progress = hass.config_entries.flow.async_progress()
+    assert len(progress) == 1
+    assert progress[0]['handler'] == 'tradfri'
+    assert progress[0]['context'] == {'source': 'import'}