implement changes

rasa/shared/core/domain.py

@@ -39,6 +39,7 @@
 )
 from rasa.shared.core.constants import (
     ACTION_SHOULD_SEND_DOMAIN,
+    SLOT_MAPPINGS,
     SlotMappingType,
     MAPPING_TYPE,
     MAPPING_CONDITIONS,
@@ -490,6 +491,13 @@ def collect_slots(slot_dict: Dict[Text, Any]) -> List[Slot]:
             slot_type = slot_dict[slot_name].pop("type", None)
             slot_class = Slot.resolve_by_type(slot_type)
 
+            if SLOT_MAPPINGS not in slot_dict[slot_name]:
+                logger.warning(
+                    f"Slot '{slot_name}' has no mappings defined. "
+                    f"We will continue with an empty list of mappings."
+                )
+                slot_dict[slot_name][SLOT_MAPPINGS] = []
+
             slot = slot_class(slot_name, **slot_dict[slot_name])
             slots.append(slot)
         return slots

rasa/shared/core/slot_mappings.py

@@ -229,7 +229,7 @@ def validate_slot_mappings(domain_slots: Dict[Text, Any]) -> None:
     )
 
     for slot_name, properties in domain_slots.items():
-        mappings = properties.get(SLOT_MAPPINGS)
+        mappings = properties.get(SLOT_MAPPINGS, [])
 
         for slot_mapping in mappings:
             SlotMapping.validate(slot_mapping, slot_name)

rasa/shared/utils/schemas/domain.yml

@@ -77,7 +77,7 @@ mapping:
             required: False
           mappings:
            type: "seq"
-           required: True
+           required: False
            allowempty: False
            sequence:
               - type: "map"

tests/shared/core/test_domain.py

@@ -1,12 +1,14 @@
 import copy
 import json
+import logging
 import re
 import textwrap
 from pathlib import Path
 import random
 from typing import Dict, List, Text, Any, Union, Set, Optional
 
 import pytest
+from pytest import LogCaptureFixture
 from pytest import WarningsRecorder
 
 from rasa.shared.exceptions import YamlSyntaxException, YamlException
@@ -2352,3 +2354,20 @@ def test_merge_yaml_domains_loads_actions_which_explicitly_need_domain():
 def test_domain_responses_with_ids_are_loaded(domain_yaml, expected) -> None:
     domain = Domain.from_yaml(domain_yaml)
     assert domain.responses == expected
+
+
+def test_domain_with_slots_without_mappings(caplog: LogCaptureFixture) -> None:
+    domain_yaml = """
+    slots:
+      slot_without_mappings:
+        type: text
+    """
+    with caplog.at_level(logging.WARN):
+        domain = Domain.from_yaml(domain_yaml)
+
+    assert isinstance(domain.slots[0].mappings, list)
+    assert len(domain.slots[0].mappings) == 0
+    assert (
+        "Slot 'slot_without_mappings' has no mappings defined. "
+        "We will continue with an empty list of mappings."
+    ) in caplog.text

tests/shared/core/test_slot_mappings.py

@@ -103,19 +103,6 @@ def test_slot_mappings_ignored_intents_during_active_loop():
     )
 
 
-def test_missing_slot_mappings_raises():
-    with pytest.raises(YamlValidationException):
-        Domain.from_yaml(
-            f"""
-            version: "{LATEST_TRAINING_DATA_FORMAT_VERSION}"
-            slots:
-              some_slot:
-                type: text
-                influence_conversation: False
-            """
-        )
-
-
 def test_slot_mappings_invalid_type_raises():
     with pytest.raises(YamlValidationException):
         Domain.from_yaml(