Test error message from broken session yaml

tests/config/test_config.py

@@ -10,6 +10,7 @@ import os
 from unittest.mock import patch
 import pytest
 import ruamel
+import subprocess
 
 from bliss.config.conductor import client
 from bliss.config.static import ConfigNode
@@ -162,6 +163,26 @@ def test_ruamel_load_error(beacon, beacon_directory):
     assert error_msg.startswith("YAML parser failure:")
 
 
+def test_broken_session_yml(beacon, beacon_directory):
+    broken_session = f"{beacon_directory}/broken_session.yml"
+
+    with open(broken_session, "w") as f:
+        f.write("foo")
+
+    bliss_shell = subprocess.Popen(
+        [sys.executable, "-m", "bliss.shell.main", "-s", "broken_session"],
+        stdout=subprocess.PIPE,
+    )
+    output, err = bliss_shell.communicate()
+
+    expected = "'broken_session' does not seem to be a valid session, "
+    expected += "it may relate to the following yaml error(s):\n"
+    expected += "Ignored 1 YAML file(s) due to parsing error(s):\n"
+    expected += "    - broken_session.yml:\n"
+    expected += "       |'str' object has no attribute 'items'\n"
+    assert expected in output.decode()
+
+
 @pytest.mark.parametrize(
     "object_name, get_func_name, copy",
     [["refs_test", "get", False], ["refs_test_cpy", "get_config", True]],