accept a left out "()" for ids on command line for better compatibility with pytest.vim

CHANGELOG

@@ -4,6 +4,8 @@ Changes between 2.0.0 and 2.0.1
 - refine and unify initial capturing so that it works nicely
   even if the logging module is used on an early-loaded conftest.py
   file or plugin.
+- allow to omit "()" in test ids to allow for uniform test ids
+  as produced by Alfredo's nice pytest.vim plugin.
 - fix issue12 - show plugin versions with "--version" and
   "--traceconfig" and also document how to add extra information 
   to reporting test header

_pytest/main.py

@@ -495,9 +495,15 @@ class Session(FSCollector):
             node.ihook.pytest_collectstart(collector=node)
             rep = node.ihook.pytest_make_collect_report(collector=node)
             if rep.passed:
+                has_matched = False
                 for x in rep.result:
                     if x.name == name:
                         resultnodes.extend(self.matchnodes([x], nextnames))
+                        has_matched = True
+                # XXX accept IDs that don't have "()" for class instances
+                if not has_matched and len(rep.result) == 1 and x.name == "()":
+                    nextnames.insert(0, name)
+                    resultnodes.extend(self.matchnodes([x], nextnames))
             node.ihook.pytest_collectreport(report=rep)
         return resultnodes
 

testing/test_collection.py

@@ -472,6 +472,21 @@ class TestSession:
         item2b, = newcol.perform_collect([item.nodeid], genitems=False)
         assert item2b == item2
 
+    def test_find_byid_without_instance_parents(self, testdir):
+        p = testdir.makepyfile("""
+            class TestClass:
+                def test_method(self):
+                    pass
+        """)
+        arg = p.basename + ("::TestClass::test_method")
+        config = testdir.parseconfig(arg)
+        rcol = Session(config)
+        rcol.perform_collect()
+        items = rcol.items
+        assert len(items) == 1
+        item, = items
+        assert item.nodeid.endswith("TestClass::()::test_method")
+
 class Test_getinitialnodes:
     def test_global_file(self, testdir, tmpdir):
         x = tmpdir.ensure("x.py")