Add originalname attribute to Function

Related to #1790

_pytest/python.py

@@ -361,7 +361,9 @@ class PyCollector(PyobjMixin, pytest.Collector):
                 yield Function(name=subname, parent=self,
                                callspec=callspec, callobj=funcobj,
                                fixtureinfo=fixtureinfo,
-                               keywords={callspec.id:True})
+                               keywords={callspec.id:True},
+                               originalname=name,
+                               )
 
 
 def _marked(func, mark):
@@ -1471,7 +1473,7 @@ class Function(FunctionMixin, pytest.Item, fixtures.FuncargnamesCompatAttr):
     _genid = None
     def __init__(self, name, parent, args=None, config=None,
                  callspec=None, callobj=NOTSET, keywords=None, session=None,
-                 fixtureinfo=None):
+                 fixtureinfo=None, originalname=None):
         super(Function, self).__init__(name, parent, config=config,
                                        session=session)
         self._args = args
@@ -1493,6 +1495,12 @@ class Function(FunctionMixin, pytest.Item, fixtures.FuncargnamesCompatAttr):
         self.fixturenames = fixtureinfo.names_closure
         self._initrequest()
 
+        #: original function name, without any decorations (for example
+        #: parametrization adds a ``"[...]"`` suffix to function names).
+        #:
+        #: .. versionadded:: 3.0
+        self.originalname = originalname
+
     def _initrequest(self):
         self.funcargs = {}
         if self._isyieldedfunction():

testing/python/collect.py

@@ -634,6 +634,15 @@ class TestFunction:
         result = testdir.runpytest()
         result.stdout.fnmatch_lines('* 3 passed in *')
 
+    def test_function_original_name(self, testdir):
+        items = testdir.getitems("""
+            import pytest
+            @pytest.mark.parametrize('arg', [1,2])
+            def test_func(arg):
+                pass
+        """)
+        assert [x.originalname for x in items] == ['test_func', 'test_func']
+
 
 class TestSorting:
     def test_check_equality(self, testdir):