Correct click.edit typing (#2804)

CHANGES.rst

@@ -94,6 +94,7 @@ Unreleased
 -   ``Option.flag_value`` will no longer have a default value set based on
     ``Option.default`` if ``Option.is_flag`` is ``False``. This results in
     ``Option.default`` not needing to implement `__bool__`. :pr:`2829`
+-   Incorrect ``click.edit`` typing has been corrected. :pr:`2804`
 
 Version 8.1.8
 -------------

src/click/_termui_impl.py

@@ -545,10 +545,18 @@ def edit_files(self, filenames: cabc.Iterable[str]) -> None:
                 _("{editor}: Editing failed: {e}").format(editor=editor, e=e)
             ) from e
 
-    def edit(self, text: t.AnyStr | None) -> t.AnyStr | None:
+    @t.overload
+    def edit(self, text: bytes | bytearray) -> bytes | None: ...
+
+    # We cannot know whether or not the type expected is str or bytes when None
+    # is passed, so str is returned as that was what was done before.
+    @t.overload
+    def edit(self, text: str | None) -> str | None: ...
+
+    def edit(self, text: str | bytes | bytearray | None) -> str | bytes | None:
         import tempfile
 
-        if not text:
+        if text is None:
             data = b""
         elif isinstance(text, (bytes, bytearray)):
             data = text
@@ -588,7 +596,7 @@ def edit(self, text: t.AnyStr | None) -> t.AnyStr | None:
             if isinstance(text, (bytes, bytearray)):
                 return rv
 
-            return rv.decode("utf-8-sig").replace("\r\n", "\n")  # type: ignore
+            return rv.decode("utf-8-sig").replace("\r\n", "\n")
         finally:
             os.unlink(name)
 

src/click/termui.py

@@ -686,12 +686,22 @@ def secho(
 
 @t.overload
 def edit(
-    text: t.AnyStr,
+    text: bytes | bytearray,
+    editor: str | None = None,
+    env: cabc.Mapping[str, str] | None = None,
+    require_save: bool = False,
+    extension: str = ".txt",
+) -> bytes | None: ...
+
+
+@t.overload
+def edit(
+    text: str,
     editor: str | None = None,
     env: cabc.Mapping[str, str] | None = None,
     require_save: bool = True,
     extension: str = ".txt",
-) -> t.AnyStr: ...
+) -> str | None: ...
 
 
 @t.overload
@@ -706,13 +716,13 @@ def edit(
 
 
 def edit(
-    text: t.AnyStr | None = None,
+    text: str | bytes | bytearray | None = None,
     editor: str | None = None,
     env: cabc.Mapping[str, str] | None = None,
     require_save: bool = True,
     extension: str = ".txt",
     filename: str | cabc.Iterable[str] | None = None,
-) -> t.AnyStr | None:
+) -> str | bytes | bytearray | None:
     r"""Edits the given text in the defined editor.  If an editor is given
     (should be the full path to the executable but the regular operating
     system search path is used for finding the executable) it overrides