introduce the pytest_configure_funcargs hook for better control on funcarg instanciation/configuration

testing/test_python.py

@@ -606,6 +606,22 @@ class TestFillFuncArgs:
         fillfuncargs(item)
         assert len(item.funcargs) == 1
 
+    def test_configure_hook(self, testdir):
+        item = testdir.getitem("def test_func(some, other=20): pass")
+        class Provider:
+            def pytest_funcarg__some(self, request):
+                return []
+            def pytest_configure_funcargs(self, request):
+                request.getfuncargvalue('some').append(1)
+        item.config.pluginmanager.register(Provider())
+        if hasattr(item, '_args'):
+            del item._args
+        from _pytest.python import fillfuncargs
+        fillfuncargs(item)
+        assert len(item.funcargs) == 1
+        assert item.funcargs['some'] == [1]
+
+
 class TestRequest:
     def test_request_attributes(self, testdir):
         item = testdir.getitem("""