improve typing for `_simple_escaping_wrapper` (#376)

2 files changed, 26 insertions, 29 deletions

diff --git a/CHANGES.rst b/CHANGES.rst
index e25c156..90476f7 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -3,6 +3,8 @@ Version 2.1.3
 
 Unreleased
 
+-   Fix static typing for basic ``str`` methods on ``Markup``. :issue:`358`
+
 
 Version 2.1.2
 -------------
diff --git a/src/markupsafe/__init__.py b/src/markupsafe/__init__.py
index b2faa46..c593a13 100644
--- a/src/markupsafe/__init__.py
+++ b/src/markupsafe/__init__.py
@@ -10,6 +10,8 @@ if t.TYPE_CHECKING:
         def __html__(self) -> str:
             pass
 
+    _P = te.ParamSpec("_P")
+
 
 __version__ = "2.1.3.dev"
 
@@ -17,16 +19,14 @@ _strip_comments_re = re.compile(r"<!--.*?-->", re.DOTALL)
 _strip_tags_re = re.compile(r"<.*?>", re.DOTALL)
 
 
-def _simple_escaping_wrapper(name: str) -> t.Callable[..., "Markup"]:
-    orig = getattr(str, name)
-
-    @functools.wraps(orig)
-    def wrapped(self: "Markup", *args: t.Any, **kwargs: t.Any) -> "Markup":
-        args = _escape_argspec(list(args), enumerate(args), self.escape)  # type: ignore
+def _simple_escaping_wrapper(func: "t.Callable[_P, str]") -> "t.Callable[_P, Markup]":
+    @functools.wraps(func)
+    def wrapped(self: "Markup", *args: "_P.args", **kwargs: "_P.kwargs") -> "Markup":
+        arg_list = _escape_argspec(list(args), enumerate(args), self.escape)
         _escape_argspec(kwargs, kwargs.items(), self.escape)
-        return self.__class__(orig(self, *args, **kwargs))
+        return self.__class__(func(self, *arg_list, **kwargs))  # type: ignore[arg-type]
 
-    return wrapped
+    return wrapped  # type: ignore[return-value]
 
 
 class Markup(str):
@@ -177,27 +177,22 @@ class Markup(str):
 
         return rv
 
-    for method in (
-        "__getitem__",
-        "capitalize",
-        "title",
-        "lower",
-        "upper",
-        "replace",
-        "ljust",
-        "rjust",
-        "lstrip",
-        "rstrip",
-        "center",
-        "strip",
-        "translate",
-        "expandtabs",
-        "swapcase",
-        "zfill",
-    ):
-        locals()[method] = _simple_escaping_wrapper(method)
-
-    del method
+    __getitem__ = _simple_escaping_wrapper(str.__getitem__)
+    capitalize = _simple_escaping_wrapper(str.capitalize)
+    title = _simple_escaping_wrapper(str.title)
+    lower = _simple_escaping_wrapper(str.lower)
+    upper = _simple_escaping_wrapper(str.upper)
+    replace = _simple_escaping_wrapper(str.replace)
+    ljust = _simple_escaping_wrapper(str.ljust)
+    rjust = _simple_escaping_wrapper(str.rjust)
+    lstrip = _simple_escaping_wrapper(str.lstrip)
+    rstrip = _simple_escaping_wrapper(str.rstrip)
+    center = _simple_escaping_wrapper(str.center)
+    strip = _simple_escaping_wrapper(str.strip)
+    translate = _simple_escaping_wrapper(str.translate)
+    expandtabs = _simple_escaping_wrapper(str.expandtabs)
+    swapcase = _simple_escaping_wrapper(str.swapcase)
+    zfill = _simple_escaping_wrapper(str.zfill)
 
     def partition(self, sep: str) -> t.Tuple["Markup", "Markup", "Markup"]:
         l, s, r = super().partition(self.escape(sep))