Add diagnostics platform to Fastdotcom (#111525)

tests/components/fastdotcom/test_diagnostics.py

@@ -0,0 +1,43 @@
+"""Test the Fast.com component diagnostics."""
+
+from unittest.mock import patch
+
+from syrupy import SnapshotAssertion
+
+from homeassistant.components.fastdotcom.const import DEFAULT_NAME, DOMAIN
+from homeassistant.config_entries import SOURCE_USER
+from homeassistant.core import HomeAssistant
+
+from tests.common import MockConfigEntry
+from tests.components.diagnostics import get_diagnostics_for_config_entry
+from tests.typing import ClientSessionGenerator
+
+
+async def test_get_config_entry_diagnostics(
+    hass: HomeAssistant,
+    hass_client: ClientSessionGenerator,
+    snapshot: SnapshotAssertion,
+) -> None:
+    """Test if get_config_entry_diagnostics returns the correct data."""
+    config_entry = MockConfigEntry(
+        version=1,
+        domain=DOMAIN,
+        title=DEFAULT_NAME,
+        source=SOURCE_USER,
+        options={},
+        entry_id="TEST_ENTRY_ID",
+        unique_id="UNIQUE_TEST_ID",
+        minor_version=1,
+    )
+    config_entry.add_to_hass(hass)
+
+    with patch(
+        "homeassistant.components.fastdotcom.coordinator.fast_com", return_value=50.3
+    ):
+        await hass.config_entries.async_setup(config_entry.entry_id)
+        await hass.async_block_till_done()
+
+    assert (
+        await get_diagnostics_for_config_entry(hass, hass_client, config_entry)
+        == snapshot
+    )