🐛 Ensure rich_markup_mode=None disables Rich formatting

docs/tutorial/commands/help.md

@@ -195,7 +195,7 @@ If you have **Rich** installed as described in [Printing and Colors](../printing
 Then you can use more formatting in the docstrings and the `help` parameter for *CLI arguments* and *CLI options*. You will see more about it below. 👇
 
 !!! info
-    By default, `rich_markup_mode` is `None`, which disables any rich text formatting.
+    By default, `rich_markup_mode` is `None` if Rich is not installed, and `"rich"` if it is installed. In the latter case, you can set `rich_markup_mode` to `None` to disable rich text formatting.
 
 ### Rich Markup
 

tests/test_rich_markup_mode.py

@@ -0,0 +1,40 @@
+import typer
+import typer.completion
+from typer.testing import CliRunner
+
+runner = CliRunner()
+rounded = ["╭", "─", "┬", "╮", "│", "├", "┼", "┤", "╰", "┴", "╯"]
+
+
+def test_rich_markup_mode_none():
+    app = typer.Typer(rich_markup_mode=None)
+
+    @app.command()
+    def main(arg: str):
+        """Main function"""
+        print(f"Hello {arg}")
+
+    assert app.rich_markup_mode is None
+
+    result = runner.invoke(app, ["World"])
+    assert "Hello World" in result.stdout
+
+    result = runner.invoke(app, ["--help"])
+    assert all(c not in result.stdout for c in rounded)
+
+
+def test_rich_markup_mode_rich():
+    app = typer.Typer(rich_markup_mode="rich")
+
+    @app.command()
+    def main(arg: str):
+        """Main function"""
+        print(f"Hello {arg}")
+
+    assert app.rich_markup_mode == "rich"
+
+    result = runner.invoke(app, ["World"])
+    assert "Hello World" in result.stdout
+
+    result = runner.invoke(app, ["--help"])
+    assert any(c in result.stdout for c in rounded)

typer/core.py

@@ -31,15 +31,18 @@
 else:
     from typing_extensions import Literal
 
+MarkupMode = Literal["markdown", "rich", None]
+
 try:
     import rich
 
     from . import rich_utils
 
+    DEFAULT_MARKUP_MODE: MarkupMode = "rich"
+
 except ImportError:  # pragma: no cover
     rich = None  # type: ignore
-
-MarkupMode = Literal["markdown", "rich", None]
+    DEFAULT_MARKUP_MODE = None
 
 
 # Copy from click.parser._split_opt
@@ -167,6 +170,7 @@ def _main(
     complete_var: Optional[str] = None,
     standalone_mode: bool = True,
     windows_expand_args: bool = True,
+    rich_markup_mode: MarkupMode = DEFAULT_MARKUP_MODE,
     **extra: Any,
 ) -> Any:
     # Typer override, duplicated from click.main() to handle custom rich exceptions
@@ -208,7 +212,7 @@ def _main(
             if not standalone_mode:
                 raise
             # Typer override
-            if rich:
+            if rich and rich_markup_mode is not None:
                 rich_utils.rich_format_error(e)
             else:
                 e.show()
@@ -238,7 +242,7 @@ def _main(
         if not standalone_mode:
             raise
         # Typer override
-        if rich:
+        if rich and rich_markup_mode is not None:
             rich_utils.rich_abort_error()
         else:
             click.echo(_("Aborted!"), file=sys.stderr)
@@ -614,7 +618,7 @@ def __init__(
         hidden: bool = False,
         deprecated: bool = False,
         # Rich settings
-        rich_markup_mode: MarkupMode = None,
+        rich_markup_mode: MarkupMode = DEFAULT_MARKUP_MODE,
         rich_help_panel: Union[str, None] = None,
     ) -> None:
         super().__init__(
@@ -665,11 +669,12 @@ def main(
             complete_var=complete_var,
             standalone_mode=standalone_mode,
             windows_expand_args=windows_expand_args,
+            rich_markup_mode=self.rich_markup_mode,
             **extra,
         )
 
     def format_help(self, ctx: click.Context, formatter: click.HelpFormatter) -> None:
-        if not rich:
+        if not rich or self.rich_markup_mode is None:
             return super().format_help(ctx, formatter)
         return rich_utils.rich_format_help(
             obj=self,
@@ -687,7 +692,7 @@ def __init__(
             Union[Dict[str, click.Command], Sequence[click.Command]]
         ] = None,
         # Rich settings
-        rich_markup_mode: MarkupMode = None,
+        rich_markup_mode: MarkupMode = DEFAULT_MARKUP_MODE,
         rich_help_panel: Union[str, None] = None,
         **attrs: Any,
     ) -> None:
@@ -727,11 +732,12 @@ def main(
             complete_var=complete_var,
             standalone_mode=standalone_mode,
             windows_expand_args=windows_expand_args,
+            rich_markup_mode=self.rich_markup_mode,
             **extra,
         )
 
     def format_help(self, ctx: click.Context, formatter: click.HelpFormatter) -> None:
-        if not rich:
+        if not rich or self.rich_markup_mode is None:
             return super().format_help(ctx, formatter)
         return rich_utils.rich_format_help(
             obj=self,

typer/main.py

@@ -14,7 +14,14 @@
 import click
 
 from .completion import get_completion_inspect_parameters
-from .core import MarkupMode, TyperArgument, TyperCommand, TyperGroup, TyperOption
+from .core import (
+    DEFAULT_MARKUP_MODE,
+    MarkupMode,
+    TyperArgument,
+    TyperCommand,
+    TyperGroup,
+    TyperOption,
+)
 from .models import (
     AnyType,
     ArgumentInfo,
@@ -132,7 +139,7 @@ def __init__(
         deprecated: bool = Default(False),
         add_completion: bool = True,
         # Rich settings
-        rich_markup_mode: MarkupMode = None,
+        rich_markup_mode: MarkupMode = Default(DEFAULT_MARKUP_MODE),
         rich_help_panel: Union[str, None] = Default(None),
         pretty_exceptions_enable: bool = True,
         pretty_exceptions_show_locals: bool = True,