Suggest close matches for unknown YAML configuration keys (#182124)

homeassistant/config.py

@@ -479,10 +479,13 @@ def stringify_invalid(
         message_prefix += f" at {_relpath(hass, annotation[0])}, line {annotation[1]}"
     path = "->".join(str(m) for m in exc.path)
     if exc.code == "extra_keys_not_allowed":
-        return (
-            f"{message_prefix}: '{exc.path[-1]}' is an invalid option for '{domain}', "
-            f"check: {path}{message_suffix}"
+        message = (
+            f"{message_prefix}: '{exc.path[-1]}' is an invalid option for '{domain}'"
         )
+        if candidates := exc.context.get("candidates"):
+            options = " or ".join(f"'{candidate}'" for candidate in candidates)
+            message += f" (did you mean {options}?)"
+        return f"{message}, check: {path}{message_suffix}"
     if exc.error_message == "required key not provided":
         return (
             f"{message_prefix}: required key '{exc.path[-1]}' not provided"

tests/test_config.py

@@ -1481,6 +1481,52 @@ async def test_component_config_validation_error_with_docs(
     assert error_records == snapshot
 
 
+@pytest.mark.parametrize(
+    ("key", "expected"),
+    [
+        pytest.param(
+            "command_topci",
+            "'command_topci' is an invalid option for 'mqtt' "
+            "(did you mean 'command_topic'?), check: command_topci",
+            id="one_candidate",
+        ),
+        pytest.param(
+            "command_t",
+            "'command_t' is an invalid option for 'mqtt' "
+            "(did you mean 'command_topic' or 'command_template'?), check: command_t",
+            id="two_candidates",
+        ),
+        pytest.param(
+            "totally_unrelated",
+            "'totally_unrelated' is an invalid option for 'mqtt', "
+            "check: totally_unrelated",
+            id="no_candidate",
+        ),
+    ],
+)
+async def test_stringify_invalid_suggests_close_keys(
+    hass: HomeAssistant, key: str, expected: str
+) -> None:
+    """Test an unknown option reports the close matches probatio found."""
+    schema = probatio.Schema(
+        {
+            probatio.Optional("command_topic"): str,
+            probatio.Optional("command_template"): str,
+        }
+    )
+    config = {key: "some-value"}
+
+    with pytest.raises(probatio.MultipleInvalid) as exc_info:
+        schema(config)
+
+    assert (
+        config_util.stringify_invalid(
+            hass, exc_info.value.errors[0], "mqtt", config, None, 500
+        )
+        == f"Invalid config for 'mqtt': {expected}"
+    )
+
+
 @pytest.mark.parametrize(
     "config_dir",
     ["packages", "packages_include_dir_named"],