Add discovery rule to quality_scale hassfest validation (#131890)

script/hassfest/quality_scale.py

@@ -17,6 +17,7 @@ from .quality_scale_validation import (
     config_entry_unloading,
     config_flow,
     diagnostics,
+    discovery,
     reauthentication_flow,
     reconfiguration_flow,
     strict_typing,
@@ -73,7 +74,7 @@ ALL_RULES = [
     # GOLD: [
     Rule("devices", ScaledQualityScaleTiers.GOLD),
     Rule("diagnostics", ScaledQualityScaleTiers.GOLD, diagnostics),
-    Rule("discovery", ScaledQualityScaleTiers.GOLD),
+    Rule("discovery", ScaledQualityScaleTiers.GOLD, discovery),
     Rule("discovery-update-info", ScaledQualityScaleTiers.GOLD),
     Rule("docs-data-update", ScaledQualityScaleTiers.GOLD),
     Rule("docs-examples", ScaledQualityScaleTiers.GOLD),

script/hassfest/quality_scale_validation/discovery.py

@@ -0,0 +1,46 @@
+"""Enforce that the integration supports discovery.
+
+https://developers.home-assistant.io/docs/core/integration-quality-scale/rules/discovery/
+"""
+
+import ast
+
+from script.hassfest.model import Integration
+
+DISCOVERY_FUNCTIONS = [
+    "async_step_discovery",
+    "async_step_bluetooth",
+    "async_step_hassio",
+    "async_step_homekit",
+    "async_step_mqtt",
+    "async_step_ssdp",
+    "async_step_zeroconf",
+    "async_step_dhcp",
+    "async_step_usb",
+]
+
+
+def _has_discovery_function(module: ast.Module) -> bool:
+    """Test if the module defines at least one of the discovery functions."""
+    return any(
+        type(item) is ast.AsyncFunctionDef and item.name in DISCOVERY_FUNCTIONS
+        for item in ast.walk(module)
+    )
+
+
+def validate(integration: Integration) -> list[str] | None:
+    """Validate that the integration implements diagnostics."""
+
+    config_flow_file = integration.path / "config_flow.py"
+    if not config_flow_file.exists():
+        return ["Integration is missing config_flow.py"]
+
+    config_flow = ast.parse(config_flow_file.read_text())
+
+    if not _has_discovery_function(config_flow):
+        return [
+            f"Integration is missing one of {DISCOVERY_FUNCTIONS} "
+            f"in {config_flow_file}"
+        ]
+
+    return None