Document that the extra "::()" is stripped from old style node ids of

class methods.

Author: RKrahl

doc/src/names.rst

@@ -39,6 +39,16 @@ look like:
 
 .. literalinclude:: ../examples/nodeid.out
 
+.. note::
+    Old versions of pytest used to include an extra "()" component to
+    the node ids of methods of test classes.  This has been
+    `removed in pytest 4.0.0`__.  pytest-dependency strips this
+    if present.  Thus, when referencing dependencies, the new style
+    node ids as described above may (and must) be used, regardless of
+    the pytest version.
+
+.. __: https://docs.pytest.org/en/latest/changelog.html#pytest-4-0-0-2018-11-13
+
 References and scope
 --------------------
 

pytest_dependency.py

@@ -72,6 +72,9 @@ def __init__(self, scope):
 
     def addResult(self, item, name, rep):
         if not name:
+            # Old versions of pytest used to add an extra "::()" to
+            # the node ids of class methods to denote the class
+            # instance.  This has been removed in pytest 4.0.0.
             nodeid = item.nodeid.replace("::()::", "::")
             if self.scope == 'session' or self.scope == 'package':
                 name = nodeid