feat: allow setting instantiate to regsiter a class as its instance

Author: pwwang

simplug.py

@@ -274,6 +274,10 @@ def __init__(self, plugin: Any, batch_index: int, index: int) -> None:
             (batch_index, index) if priority is None else (priority, batch_index)
         )
 
+        instantiate = getattr(self.plugin, "instantiate", False)
+        if instantiate and inspect.isclass(self.plugin):
+            self.plugin = self.plugin()
+
         self.enabled = True  # type: bool
 
     @property

tests/test_simplug.py

@@ -2001,6 +2001,8 @@ def hook2(arg):
             ...
 
     class PluginBase:
+        instantiate = True
+
         @simplug.impl
         def hook1(self, arg):
             return arg + 1
@@ -2014,12 +2016,12 @@ def hook2(arg):
     assert pb.hook2(1) == 3
     assert PluginBase.hook2(1) == 3
 
-    with pytest.warns(ImplMightNeedInstanceWarning):
-        simplug.register(PluginBase)
+    simplug.register(PluginBase)
     assert simplug.hooks.hook1(1) == [2]
     assert simplug.hooks.hook2(1) == [3]
 
     class PluginChild(PluginBase):
+        instantiate = False
 
         def __init__(self, name="pluginchild"):
             self.name = name