fix: respect TYPER_USE_RICH in shell completion help text (fixes #1643)

tests/test_completion/test_sanitization.py

@@ -36,3 +36,32 @@ def test_sanitize_help_text(
     with patch("importlib.util.find_spec", return_value=find_spec) as mock_find_spec:
         assert _sanitize_help_text(help_text) == expected
     mock_find_spec.assert_called_once_with("rich")
+
+
+@pytest.mark.parametrize(
+    "has_rich, help_text, expected",
+    [
+        (
+            False,
+            "help [bold]with[/] rich tags",
+            "help [bold]with[/] rich tags",
+        ),
+        (
+            True,
+            "help [bold]with[/] rich tags",
+            "help with rich tags",
+        ),
+    ],
+)
+def test_sanitize_help_text_respects_has_rich(
+    has_rich: bool, help_text: str, expected: str
+):
+    """When HAS_RICH is False, rich tags are preserved even if rich is installed."""
+    with (
+        patch("typer._completion_classes.HAS_RICH", has_rich),
+        patch(
+            "importlib.util.find_spec",
+            return_value=ModuleSpec("rich", loader=None),
+        ),
+    ):
+        assert _sanitize_help_text(help_text) == expected

typer/_completion_classes.py

@@ -14,12 +14,19 @@
     COMPLETION_SCRIPT_ZSH,
     Shells,
 )
+from .core import HAS_RICH
 
 
 def _sanitize_help_text(text: str) -> str:
-    """Sanitizes the help text by removing rich tags"""
+    """Sanitizes the help text by removing rich tags.
+
+    Checks both that rich is installed AND that it is enabled
+    (respecting the TYPER_USE_RICH environment variable).
+    """
     if not importlib.util.find_spec("rich"):
         return text
+    if not HAS_RICH:
+        return text
     from . import rich_utils
 
     return rich_utils.rich_render_text(text)