feat: show message when enabling demo trading mode

freqtrade/exchange/exchange.py

@@ -875,10 +875,11 @@ class Exchange:
         """Validate demo trading configuration
         Prevents accidental configuration with wrong expectations.
         """
-        if exchange_conf.get("demo_trading", False) and not self.get_option(
-            "supports_demo_trading"
-        ):
-            raise ConfigurationError(f"Demo trading is not supported for {self.name}.")
+        if exchange_conf.get("demo_trading", False):
+            if not self.get_option("supports_demo_trading"):
+                raise ConfigurationError(f"Demo trading is not supported for {self.name}.")
+            else:
+                logger.info(f"Demo trading enabled for {self.name}")
 
     def validate_required_startup_candles(self, startup_candles: int, timeframe: str) -> int:
         """

tests/exchange/test_exchange.py

@@ -349,7 +349,6 @@ def test_validate_freqai_compat(default_conf, mocker, caplog):
 
 
 def test_validate_demo_trading(default_conf_usdt, mocker, caplog):
-    caplog.set_level(logging.INFO)
     # Test - nothing enabled so nothing happens
     ex = get_patched_exchange(mocker, default_conf_usdt, exchange="kraken")
     ex.validate_demo_trading(default_conf_usdt["exchange"])
@@ -358,8 +357,11 @@ def test_validate_demo_trading(default_conf_usdt, mocker, caplog):
     with pytest.raises(ConfigurationError, match=r"Demo trading is not supported for .*"):
         ex.validate_demo_trading(default_conf_usdt["exchange"])
 
+    msg = r"Demo trading enabled for .*"
+    assert not log_has_re(msg, caplog)
     ex_bybit = get_patched_exchange(mocker, default_conf_usdt, exchange="bybit")
     ex_bybit.validate_demo_trading(default_conf_usdt["exchange"])
+    assert log_has_re(msg, caplog)
 
 
 @pytest.mark.parametrize(