Add diagnostics platform to Xiaomi Miio integration (#69985)

.coveragerc

@@ -1426,6 +1426,7 @@ omit =
     homeassistant/components/xiaomi_miio/button.py
     homeassistant/components/xiaomi_miio/device.py
     homeassistant/components/xiaomi_miio/device_tracker.py
+    homeassistant/components/xiaomi_miio/diagnostics.py
     homeassistant/components/xiaomi_miio/fan.py
     homeassistant/components/xiaomi_miio/gateway.py
     homeassistant/components/xiaomi_miio/humidifier.py

homeassistant/components/xiaomi_miio/diagnostics.py

@@ -0,0 +1,35 @@
+"""Diagnostics support for Xiaomi Miio."""
+from __future__ import annotations
+
+from homeassistant.components.diagnostics import async_redact_data
+from homeassistant.config_entries import ConfigEntry
+from homeassistant.const import CONF_MAC, CONF_TOKEN, CONF_UNIQUE_ID
+from homeassistant.core import HomeAssistant
+
+from .const import CONF_CLOUD_PASSWORD, CONF_CLOUD_USERNAME, DOMAIN, KEY_COORDINATOR
+
+TO_REDACT = {
+    CONF_CLOUD_PASSWORD,
+    CONF_CLOUD_USERNAME,
+    CONF_MAC,
+    CONF_TOKEN,
+    CONF_UNIQUE_ID,
+}
+
+
+async def async_get_config_entry_diagnostics(
+    hass: HomeAssistant, config_entry: ConfigEntry
+) -> dict:
+    """Return diagnostics for a config entry."""
+    diagnostics_data = {
+        "config_entry": async_redact_data(config_entry.as_dict(), TO_REDACT)
+    }
+
+    # not every device uses DataUpdateCoordinator
+    if coordinator := hass.data[DOMAIN][config_entry.entry_id].get(KEY_COORDINATOR):
+        if isinstance(coordinator.data, dict):
+            diagnostics_data["coordinator_data"] = coordinator.data
+        else:
+            diagnostics_data["coordinator_data"] = coordinator.data.__repr__()
+
+    return diagnostics_data