specialize make_hook_caller to work with a subset of the registered plugins.

--HG--
branch : more_plugin

_pytest/config.py

@@ -197,6 +197,7 @@ class PytestPluginManager(PluginManager):
                 if conftestpath.check(file=1):
                     mod = self._importconftest(conftestpath)
                     clist.append(mod)
+
             self._path2confmods[path] = clist
             return clist
 
@@ -220,6 +221,7 @@ class PytestPluginManager(PluginManager):
                 mod = conftestpath.pyimport()
             except Exception:
                 raise ConftestImportFailure(conftestpath, sys.exc_info())
+
             self._conftestpath2mod[conftestpath] = mod
             dirpath = conftestpath.dirpath()
             if dirpath in self._path2confmods:

_pytest/core.py

@@ -236,6 +236,21 @@ class PluginManager(object):
 
         return TracedHookExecution(self, before, after).undo
 
+    def subset_hook_caller(self, name, remove_plugins):
+        """ Return a new HookCaller instance which manages calls to
+        the plugins but without hooks from remove_plugins taking part. """
+        hc = getattr(self.hook, name)
+        plugins_to_remove = [plugin for plugin in remove_plugins
+                                    if hasattr(plugin, name)]
+        if plugins_to_remove:
+            hc = hc.clone()
+            for plugin in plugins_to_remove:
+                hc._remove_plugin(plugin)
+            # we also keep track of this hook caller so it
+            # gets properly removed on plugin unregistration
+            self._plugin2hookcallers.setdefault(plugin, []).append(hc)
+        return hc
+
     def make_hook_caller(self, name, plugins):
         """ Return a new HookCaller instance which manages calls to
         all methods named "name" in the plugins. The new hook caller

_pytest/main.py

@@ -362,9 +362,6 @@ class Node(object):
     def listnames(self):
         return [x.name for x in self.listchain()]
 
-    def getplugins(self):
-        return self.config._getmatchingplugins(self.fspath)
-
     def addfinalizer(self, fin):
         """ register a function to be called when this node is finalized.
 

testing/test_core.py

@@ -195,6 +195,44 @@ class TestPluginManager:
         hc(arg=2)
         assert l == [10]
 
+    def test_subset_hook_caller(self, pm):
+        class Hooks:
+            def he_method1(self, arg):
+                pass
+        pm.addhooks(Hooks)
+
+        l = []
+        class Plugin1:
+            def he_method1(self, arg):
+                l.append(arg)
+        class Plugin2:
+            def he_method1(self, arg):
+                l.append(arg*10)
+        class PluginNo:
+            pass
+
+        plugin1, plugin2, plugin3 = Plugin1(), Plugin2(), PluginNo()
+        pm.register(plugin1)
+        pm.register(plugin2)
+        pm.register(plugin3)
+        pm.hook.he_method1(arg=1)
+        assert l == [10, 1]
+        l[:] = []
+
+        hc = pm.subset_hook_caller("he_method1", [plugin1])
+        hc(arg=2)
+        assert l == [20]
+        l[:] = []
+
+        hc = pm.subset_hook_caller("he_method1", [plugin2])
+        hc(arg=2)
+        assert l == [2]
+        l[:] = []
+
+        pm.unregister(plugin1)
+        hc(arg=2)
+        assert l == []
+
 
 class TestAddMethodOrdering:
     @pytest.fixture