fix(cli): pre parse launch arguments when cli command executed (#4161)

Author: mmev

litestar/cli/_utils.py

@@ -190,7 +190,10 @@ def __init__(
     ) -> None:
         """Init ``LitestarExtensionGroup``"""
         super().__init__(name=name, commands=commands, **attrs)
+
         self._prepare_done = False
+        self._preparsed_app_dir: str | None = None
+        self._preparsed_app_path: Path | None = None
 
         for entry_point in entry_points(group="litestar.commands"):
             command = entry_point.load()
@@ -205,7 +208,9 @@ def _prepare(self, ctx: Context) -> None:
             env: LitestarEnv | None = ctx.obj
         else:
             try:
-                env = ctx.obj = LitestarEnv.from_env(ctx.params.get("app_path"), ctx.params.get("app_dir"))
+                app_path = ctx.params.get("app_path", self._preparsed_app_path)
+                app_dir = ctx.params.get("app_dir", self._preparsed_app_dir)
+                env = ctx.obj = LitestarEnv.from_env(app_path, app_dir)
             except LitestarCLIException:
                 env = None
 
@@ -226,6 +231,23 @@ def make_context(  # type: ignore[override]
         self._prepare(ctx)
         return ctx
 
+    def parse_args(self, ctx: Context, args: list[str]) -> list[str]:
+        """Preparse launch arguments and save app_path & app_dir to slots.
+        This block is triggered in any case, but its results are only used if the --help command is invoked.
+        """
+        parser = self.make_parser(ctx)
+
+        original_ignore_unknown_option = ctx.ignore_unknown_options
+        ctx.ignore_unknown_options = True
+
+        opts, remaining_args, order = parser.parse_args(list(args))
+        self._preparsed_app_path = opts.get("app_path", None)
+        self._preparsed_app_dir = opts.get("app_dir", None)
+
+        ctx.ignore_unknown_options = original_ignore_unknown_option
+
+        return super().parse_args(ctx, args)
+
     def list_commands(self, ctx: Context) -> list[str]:
         self._prepare(ctx)
         return super().list_commands(ctx)

tests/unit/test_cli/conftest.py

@@ -25,7 +25,7 @@
 if TYPE_CHECKING:
     from unittest.mock import MagicMock
 
-    from litestar.cli._utils import LitestarGroup
+    from litestar.cli._utils import LitestarExtensionGroup
 
 
 @pytest.fixture(autouse=True)
@@ -34,10 +34,10 @@ def reset_litestar_app_env(monkeypatch: MonkeyPatch) -> None:
 
 
 @pytest.fixture()
-def root_command() -> LitestarGroup:
+def root_command() -> LitestarExtensionGroup:
     import litestar.cli.main
 
-    return cast("LitestarGroup", importlib.reload(litestar.cli.main).litestar_group)
+    return cast("LitestarExtensionGroup", importlib.reload(litestar.cli.main).litestar_group)
 
 
 @pytest.fixture

tests/unit/test_cli/test_cli_plugin.py

@@ -1,28 +1,43 @@
-import textwrap
-
 from click.testing import CliRunner
 
-from litestar.cli._utils import LitestarGroup
+from litestar.cli._utils import LitestarExtensionGroup
 from tests.unit.test_cli.conftest import CreateAppFileFixture
 
+APPLICATION_WITH_CLI_PLUGIN = """
+from litestar import Litestar
+from litestar.plugins import CLIPluginProtocol
+
+class CLIPlugin(CLIPluginProtocol):
+    def on_cli_init(self, cli):
+        @cli.command()
+        def mycommand(app: Litestar):
+            \"\"\"Description of plugin command\"\"\"
+            print(f"App is loaded: {app is not None}")
 
-def test_basic_command(runner: CliRunner, create_app_file: CreateAppFileFixture, root_command: LitestarGroup) -> None:
-    app_file_content = textwrap.dedent(
-        """
-    from litestar import Litestar
-    from litestar.plugins import CLIPluginProtocol
+app = Litestar(plugins=[CLIPlugin()])
+"""
 
-    class CLIPlugin(CLIPluginProtocol):
-        def on_cli_init(self, cli):
-            @cli.command()
-            def foo(app: Litestar):
-                print(f"App is loaded: {app is not None}")
 
-    app = Litestar(plugins=[CLIPlugin()])
-    """
-    )
-    app_file = create_app_file("command_test_app.py", content=app_file_content)
-    result = runner.invoke(root_command, ["--app", f"{app_file.stem}:app", "foo"])
+def test_basic_command(
+    runner: CliRunner,
+    create_app_file: CreateAppFileFixture,
+    root_command: LitestarExtensionGroup,
+) -> None:
+    app_file = create_app_file("command_test_app.py", content=APPLICATION_WITH_CLI_PLUGIN)
+    result = runner.invoke(root_command, ["--app", f"{app_file.stem}:app", "mycommand"])
 
     assert not result.exception
     assert "App is loaded: True" in result.output
+
+
+def test_plugin_command_appears_in_help_message(
+    runner: CliRunner,
+    create_app_file: CreateAppFileFixture,
+    root_command: LitestarExtensionGroup,
+) -> None:
+    app_file = create_app_file("command_test_app.py", content=APPLICATION_WITH_CLI_PLUGIN)
+    result = runner.invoke(root_command, ["--app", f"{app_file.stem}:app", "--help"])
+
+    assert not result.exception
+    assert "mycommand" in result.output
+    assert "Description of plugin command" in result.output