Validate that either networks, ap, or improv is set up (#1910)

esphome/components/wifi/__init__.py

@@ -137,6 +137,18 @@ WIFI_NETWORK_STA = WIFI_NETWORK_BASE.extend(
 )
 
 
+def validate(config, item_config):
+    if (
+        (CONF_NETWORKS in item_config)
+        and (item_config[CONF_NETWORKS] == [])
+        and (CONF_AP not in item_config)
+    ):
+        if "esp32_improv" not in config:
+            raise ValueError(
+                "Please specify at least an SSID or an Access Point to create."
+            )
+
+
 def _validate(config):
     if CONF_PASSWORD in config and CONF_SSID not in config:
         raise cv.Invalid("Cannot have WiFi password without SSID!")