Add test for start_websever

tests/commands/test_commands.py

@@ -16,6 +16,7 @@ from freqtrade.commands import (start_convert_data, start_create_userdir, start_
                                 start_test_pairlist, start_trading)
 from freqtrade.commands.deploy_commands import (clean_ui_subdir, download_and_install_ui,
                                                 get_ui_download_url, read_ui_version)
+from freqtrade.commands.trade_commands import start_webserver
 from freqtrade.configuration import setup_utils_configuration
 from freqtrade.enums import RunMode
 from freqtrade.exceptions import OperationalException
@@ -58,6 +59,18 @@ def test_start_trading_fail(mocker, caplog):
     assert log_has('Fatal exception!', caplog)
 
 
+def test_start_webserver(mocker, caplog):
+
+    api_server_mock = mocker.patch("freqtrade.rpc.api_server.ApiServer", )
+
+    args = [
+        'webserver',
+        '-c', 'config_bittrex.json.example'
+    ]
+    start_webserver(get_args(args))
+    assert api_server_mock.call_count == 1
+
+
 def test_list_exchanges(capsys):
 
     args = [