🩺 [#4284] Add DMN plugin config check to digest email

Detect which DMN plugins are enabled and used in (live) forms, and
run the config check for them. If problems are detected, they will
be reported in the digest email.

src/openforms/emails/digest.py

@@ -18,8 +18,10 @@
 
 from openforms.contrib.brk.service import check_brk_config_for_addressNL
 from openforms.contrib.kadaster.service import check_bag_config_for_address_fields
+from openforms.dmn.registry import register as dmn_register
 from openforms.forms.constants import LogicActionTypes
 from openforms.forms.models import Form
+from openforms.forms.models.form import FormQuerySet
 from openforms.forms.models.form_registration_backend import FormRegistrationBackend
 from openforms.forms.models.logic import FormLogic
 from openforms.logging.models import TimelineLogProxy
@@ -255,6 +257,22 @@ def collect_broken_configurations() -> list[BrokenConfiguration]:
             )
         )
 
+    # check DMN usage for each plugin and if used, validate the plugin config
+    for plugin in dmn_register.iter_enabled_plugins():
+        has_forms = _get_forms_with_dmn_action(plugin.identifier).exists()
+        if not has_forms:
+            continue
+
+        try:
+            plugin.check_config()
+        except InvalidPluginConfiguration as exc:
+            broken_configurations.append(
+                BrokenConfiguration(
+                    config_name=_("{plugin} (DMN)").format(plugin=plugin.verbose_name),
+                    exception_message=exc.message,
+                )
+            )
+
     return broken_configurations
 
 
@@ -456,3 +474,21 @@ def _report():
             )
 
     return invalid_logic_rules
+
+
+def _get_forms_with_dmn_action(plugin_id: str) -> FormQuerySet:
+    # actions is a JSONField - the top-level is an array of actions. Each action is
+    # an object with the shape openforms.submissions.logic.actions.ActionDict. The
+    # JSONField query does not fully specify all properties because it performs
+    # structural matching (and we only process the rest of the config after establishing
+    # that it is indeed the expected action type).
+    lookup_value = [
+        {
+            "action": {
+                "type": LogicActionTypes.evaluate_dmn,
+                "config": {"plugin_id": plugin_id},
+            }
+        }
+    ]
+    base_qs = Form.objects.live().distinct()
+    return base_qs.filter(formlogic__actions__contains=lookup_value)