docs: mock cryptography import due to build errors

docs/conf.py

@@ -85,7 +85,7 @@ autoclass_content = "both"
 
 autodoc_member_order = "groupwise"
 
-autodoc_mock_imports = ["pyalpm"]
+autodoc_mock_imports = ["cryptography", "pyalpm"]
 
 autodoc_default_options = {
     "no-undoc-members": True,

src/ahriman/application/ahriman.py

@@ -90,7 +90,7 @@ def _parser() -> argparse.ArgumentParser:
                         type=int, default=-1)
     parser.add_argument("-V", "--version", action="version", version=__version__)
 
-    subparsers = parser.add_subparsers(title="command", help="command to run", dest="command", required=True)
+    subparsers = parser.add_subparsers(title="command", help="command to run", dest="command")
 
     _set_aur_search_parser(subparsers)
     _set_help_parser(subparsers)
@@ -1016,5 +1016,8 @@ def run() -> int:
     args_parser = _parser()
     args = args_parser.parse_args()
 
+    if args.command is None:  # in case of empty command we would like to print help message
+        args_parser.exit(status=2, message=args_parser.format_help())
+
     handler: handlers.Handler = args.handler
     return handler.execute(args)

tests/ahriman/application/test_ahriman.py

@@ -1,4 +1,5 @@
 import argparse
+import pytest
 
 from pathlib import Path
 from pytest_mock import MockerFixture
@@ -841,8 +842,20 @@ def test_run(args: argparse.Namespace, mocker: MockerFixture) -> None:
     application must be run
     """
     args.architecture = "x86_64"
+    args.command = ""
     args.handler = Handler
 
     mocker.patch("argparse.ArgumentParser.parse_args", return_value=args)
 
     assert ahriman.run() == 1
+
+
+def test_run_without_command(args: argparse.Namespace, mocker: MockerFixture) -> None:
+    """
+    must show help message if run without commands
+    """
+    args.command = None
+    mocker.patch("argparse.ArgumentParser.parse_args", return_value=args)
+
+    with pytest.raises(SystemExit):
+        ahriman.run()