fix historic hook calling some more, add docstring

Author: hpk42

CHANGELOG

@@ -1,3 +1,10 @@
+0.4.1
+-----
+
+- fix bug where callbacks for historic hooks would not be called for
+  already registered plugins.  Thanks Simon Gmizelj for the PR
+  and holger krekel for further fixes.
+
 0.4.0
 -----
 

pluggy.py

@@ -67,7 +67,7 @@
 import sys
 import inspect
 
-__version__ = '0.4.0'
+__version__ = '0.4.1'
 
 __all__ = ["PluginManager", "PluginValidationError", "HookCallError",
            "HookspecMarker", "HookimplMarker"]
@@ -745,11 +745,17 @@ def __call__(self, **kwargs):
         return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
 
     def call_historic(self, proc=None, kwargs=None):
+        """ call the hook with given ``kwargs`` for all registered plugins and
+        for all plugins which will be registered afterwards.
+
+        If ``proc`` is not None it will be called for for each non-None result
+        obtained from a hook implementation.
+        """
         self._call_history.append((kwargs or {}, proc))
         # historizing hooks don't return results
         res = self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
-        if res and proc is not None:
-            proc(res[0])
+        for x in res or []:
+            proc(x)
 
     def call_extra(self, methods, kwargs):
         """ Call the hook with some additional temporarily participating

testing/test_pluggy.py

@@ -212,24 +212,37 @@ def he_method1(self, arg):
         pm.register(Plugin())
         assert l == [10]
 
-    def test_with_immediate_result_memorized(self, pm):
+    def test_with_callbacks_immediately_executed(self, pm):
         class Hooks:
             @hookspec(historic=True)
             def he_method1(self, arg):
                 pass
         pm.add_hookspecs(Hooks)
 
-        class Plugin:
+        class Plugin1:
             @hookimpl
             def he_method1(self, arg):
                 return arg * 10
 
+        class Plugin2:
+            @hookimpl
+            def he_method1(self, arg):
+                return arg * 20
+
+        class Plugin3:
+            @hookimpl
+            def he_method1(self, arg):
+                return arg * 30
+
         l = []
-        pm.register(Plugin())
+        pm.register(Plugin1())
+        pm.register(Plugin2())
 
         he_method1 = pm.hook.he_method1
         he_method1.call_historic(lambda res: l.append(res), dict(arg=1))
-        assert l == [10]
+        assert l == [20, 10]
+        pm.register(Plugin3())
+        assert l == [20, 10, 30]
 
     def test_register_historic_incompat_hookwrapper(self, pm):
         class Hooks: