fix 889f81a, better logic/type-hints, update mypy comment

sopel/plugin.py

@@ -29,6 +29,7 @@
 
 
 if TYPE_CHECKING:
+    from collections.abc import Iterable
     from sopel.bot import SopelWrapper
 
 __all__ = [
@@ -1773,23 +1774,23 @@ class example:
     def __init__(
         self,
         msg: str,
-        result: Optional[Union[str, List[str]]] = None,
+        result: Optional[Union[str, Iterable[str]]] = None,
         privmsg: bool = False,
         admin: bool = False,
         owner: bool = False,
         repeat: int = 1,
         re: bool = False,
-        ignore: Optional[Union[str, List[str]]] = None,
+        ignore: Optional[Union[str, Iterable[str]]] = None,
         user_help: bool = False,
         online: bool = False,
         vcr: bool = False,
     ):
         # Wrap result into a list for get_example_test
-        self.result: Optional[List[str]] = None
-        if isinstance(result, list):
-            self.result = result
-        elif result is not None:
+        self.result: Optional[list[str]] = None
+        if isinstance(result, str):
             self.result = [result]
+        elif result is not None:
+            self.result = list(result)
 
         self.use_re = re
         self.msg = msg
@@ -1800,17 +1801,16 @@ def __init__(
         self.online = online
         self.vcr = vcr
 
-        if isinstance(ignore, list):
-            self.ignore = ignore
-        elif ignore is not None:
+        self.ignore: list[str] = []
+        if isinstance(ignore, str):
             self.ignore = [ignore]
-        else:
-            self.ignore = []
+        elif ignore is not None:
+            self.ignore = list(ignore)
 
         self.user_help = user_help
 
     def __call__(self, func):
-        # mypy (as of v1.3) doesn't recognize the below check as adding an
+        # mypy (as of v1.4) doesn't recognize the below check as adding an
         # "example" attribute to `func` if it's missing, so the `func`
         # argument isn't typed yet.
         # When we're ready to type-hint `loader`, we can make a TypeVar like