Validate empty sentence triggers (#103579)

* Validate empty sentence triggers

* Add extra test for no sentences

* Remove extra line

---------

Co-authored-by: Michael Hansen <mike@rhasspy.org>

homeassistant/components/conversation/trigger.py

@@ -26,11 +26,23 @@ def has_no_punctuation(value: list[str]) -> list[str]:
     return value
 
 
+def has_one_non_empty_item(value: list[str]) -> list[str]:
+    """Validate result has at least one item."""
+    if len(value) < 1:
+        raise vol.Invalid("at least one sentence is required")
+
+    for sentence in value:
+        if not sentence:
+            raise vol.Invalid(f"sentence too short: '{sentence}'")
+
+    return value
+
+
 TRIGGER_SCHEMA = cv.TRIGGER_BASE_SCHEMA.extend(
     {
         vol.Required(CONF_PLATFORM): DOMAIN,
         vol.Required(CONF_COMMAND): vol.All(
-            cv.ensure_list, [cv.string], has_no_punctuation
+            cv.ensure_list, [cv.string], has_one_non_empty_item, has_no_punctuation
         ),
     }
 )

tests/components/conversation/test_trigger.py

@@ -194,6 +194,42 @@ async def test_fails_on_punctuation(hass: HomeAssistant, command: str) -> None:
         )
 
 
+@pytest.mark.parametrize(
+    "command",
+    [""],
+)
+async def test_fails_on_empty(hass: HomeAssistant, command: str) -> None:
+    """Test that validation fails when sentences are empty."""
+    with pytest.raises(vol.Invalid):
+        await trigger.async_validate_trigger_config(
+            hass,
+            [
+                {
+                    "id": "trigger1",
+                    "platform": "conversation",
+                    "command": [
+                        command,
+                    ],
+                },
+            ],
+        )
+
+
+async def test_fails_on_no_sentences(hass: HomeAssistant) -> None:
+    """Test that validation fails when no sentences are provided."""
+    with pytest.raises(vol.Invalid):
+        await trigger.async_validate_trigger_config(
+            hass,
+            [
+                {
+                    "id": "trigger1",
+                    "platform": "conversation",
+                    "command": [],
+                },
+            ],
+        )
+
+
 async def test_wildcards(hass: HomeAssistant, calls, setup_comp) -> None:
     """Test wildcards in trigger sentences."""
     assert await async_setup_component(