Added more code coverage with unit tests

Author: kmvanbrunt

cmd2/cmd2.py

@@ -2573,6 +2573,10 @@ def complete_help_subcommand(self, text: str, line: str, begidx: int, endidx: in
         if not tokens:
             return []
 
+        # Must have at least 3 args for 'help command subcommand'
+        if len(tokens) < 3:
+            return []
+
         # Find where the command is by skipping past any flags
         cmd_index = 1
         for cur_token in tokens[cmd_index:]:

tests/test_completion.py

@@ -948,6 +948,23 @@ def test_cmd2_help_subcommand_completion_with_flags_before_command(scu_app):
     first_match = complete_tester(text, line, begidx, endidx, scu_app)
     assert first_match is not None and scu_app.completion_matches == ['bar', 'foo', 'sport']
 
+def test_complete_help_subcommand_with_no_command(scu_app):
+    # No command because not enough tokens
+    text = ''
+    line = 'help '
+    endidx = len(line)
+    begidx = endidx - len(text)
+
+    assert not scu_app.complete_help_subcommand(text, line, begidx, endidx)
+
+    # No command because everything is a flag
+    text = '-v'
+    line = 'help -f -v'
+    endidx = len(line)
+    begidx = endidx - len(text)
+
+    assert not scu_app.complete_help_subcommand(text, line, begidx, endidx)
+
 
 def test_cmd2_help_subcommand_completion_nomatch_scu(scu_app):
     text = 'z'