🐛 Fix context_settings for a Typer app with a single command (#210)

Co-authored-by: Sebastián Ramírez <tiangolo@gmail.com>

tests/test_others.py

@@ -232,3 +232,14 @@ def test_forward_references():
         "arg1: <class 'str'> Hello\narg2: <class 'int'> 2\narg3: <class 'int'> 3\narg4: <class 'bool'> True\narg5: <class 'bool'> True\n"
         in result.stdout
     )
+
+
+def test_context_settings_inheritance_single_command():
+    app = typer.Typer(context_settings=dict(help_option_names=["-h", "--help"]))
+
+    @app.command()
+    def main(name: str):
+        pass  # pragma: nocover
+
+    result = runner.invoke(app, ["main", "-h"])
+    assert "Show this message and exit." in result.stdout

typer/main.py

@@ -236,7 +236,14 @@ def get_command(typer_instance: Typer) -> click.Command:
         return click_command
     elif len(typer_instance.registered_commands) == 1:
         # Create a single Command
-        click_command = get_command_from_info(typer_instance.registered_commands[0])
+        single_command = typer_instance.registered_commands[0]
+
+        if not single_command.context_settings and not isinstance(
+            typer_instance.info.context_settings, DefaultPlaceholder
+        ):
+            single_command.context_settings = typer_instance.info.context_settings
+
+        click_command = get_command_from_info(single_command)
         if typer_instance._add_completion:
             click_command.params.append(click_install_param)
             click_command.params.append(click_show_param)