WIP/RFC: remove pytest.python.Instance [ci skip]

src/_pytest/compat.py

@@ -377,7 +377,6 @@ def safe_str(v):
     "Module",
     "Generator",
     "Function",
-    "Instance",
     "Session",
     "Item",
     "Class",

src/_pytest/mark/legacy.py

@@ -38,11 +38,8 @@ def from_item(cls, item):
         mapped_names = set()
 
         # Add the names of the current item and any parent items
-        import pytest
-
         for item in item.listchain():
-            if not isinstance(item, pytest.Instance):
-                mapped_names.add(item.name)
+            mapped_names.add(item.name)
 
         # Add the names added as extra keywords to current or parent items
         for name in item.listextrakeywords():

src/_pytest/nodes.py

@@ -119,7 +119,6 @@ def ihook(self):
 
     Module = _CompatProperty("Module")
     Class = _CompatProperty("Class")
-    Instance = _CompatProperty("Instance")
     Function = _CompatProperty("Function")
     File = _CompatProperty("File")
     Item = _CompatProperty("Item")

src/_pytest/nose.py

@@ -34,8 +34,9 @@ def pytest_runtest_setup(item):
             gen = item.parent
             if not hasattr(gen, "_nosegensetup"):
                 call_optional(gen.obj, "setup")
-                if isinstance(gen.parent, python.Instance):
-                    call_optional(gen.parent.obj, "setup")
+                # XXX
+                # if isinstance(gen.parent, python.Instance):
+                #     call_optional(gen.parent.obj, "setup")
                 gen._nosegensetup = True
         if not call_optional(item.obj, "setup"):
             # call module level setup if there is no object level one

src/_pytest/python.py

@@ -232,7 +232,6 @@ def pytest_make_parametrize_id(config, val, argname=None):
 class PyobjContext(object):
     module = pyobj_property("Module")
     cls = pyobj_property("Class")
-    instance = pyobj_property("Instance")
 
 
 class PyobjMixin(PyobjContext):
@@ -268,8 +267,6 @@ def getmodpath(self, stopatmodule=True, includemodule=False):
         chain.reverse()
         parts = []
         for node in chain:
-            if isinstance(node, Instance):
-                continue
             name = node.name
             if isinstance(node, Module):
                 name = os.path.splitext(name)[0]
@@ -629,26 +626,30 @@ def _get_xunit_func(obj, name):
 class Class(PyCollector):
     """ Collector for test methods. """
 
+    def _getobj(self):
+        return getattr(self.parent.obj, self.name)()
+
     def collect(self):
         if not safe_getattr(self.obj, "__test__", True):
             return []
-        if hasinit(self.obj):
+        if hasinit(self.obj.__class__):
             self.warn(
                 PytestWarning(
                     "cannot collect test class %r because it has a "
                     "__init__ constructor" % self.obj.__name__
                 )
             )
             return []
-        elif hasnew(self.obj):
+        elif hasnew(self.obj.__class__):
             self.warn(
                 PytestWarning(
                     "cannot collect test class %r because it has a "
                     "__new__ constructor" % self.obj.__name__
                 )
             )
             return []
-        return [self._getcustomclass("Instance")(name="()", parent=self)]
+        self.session._fixturemanager.parsefactories(self)
+        return super(Class, self).collect()
 
     def setup(self):
         setup_class = _get_xunit_func(self.obj, "setup_class")
@@ -662,24 +663,6 @@ def setup(self):
             self.addfinalizer(lambda: fin_class(self.obj))
 
 
-class Instance(PyCollector):
-    _ALLOW_MARKERS = False  # hack, destroy later
-    # instances share the object with their parents in a way
-    # that duplicates markers instances if not taken out
-    # can be removed at node structure reorganization time
-
-    def _getobj(self):
-        return self.parent.obj()
-
-    def collect(self):
-        self.session._fixturemanager.parsefactories(self)
-        return super(Instance, self).collect()
-
-    def newinstance(self):
-        self.obj = self._getobj()
-        return self.obj
-
-
 class FunctionMixin(PyobjMixin):
     """ mixin for the code common to Function and Generator.
     """
@@ -688,9 +671,6 @@ def setup(self):
         """ perform setup for this test function. """
         if hasattr(self, "_preservedparent"):
             obj = self._preservedparent
-        elif isinstance(self.parent, Instance):
-            obj = self.parent.newinstance()
-            self.obj = self._getobj()
         else:
             obj = self.parent.obj
         if inspect.ismethod(self.obj):

src/pytest.py

@@ -29,7 +29,6 @@
 from _pytest.python import Class
 from _pytest.python import Function
 from _pytest.python import Generator
-from _pytest.python import Instance
 from _pytest.python import Module
 from _pytest.python import Package
 from _pytest.python_api import approx
@@ -61,7 +60,6 @@
     "hookimpl",
     "hookspec",
     "importorskip",
-    "Instance",
     "Item",
     "main",
     "mark",

testing/python/collect.py

@@ -1370,7 +1370,6 @@ def test_collector_attributes(testdir):
         def pytest_pycollect_makeitem(collector):
             assert collector.Function == pytest.Function
             assert collector.Class == pytest.Class
-            assert collector.Instance == pytest.Instance
             assert collector.Module == pytest.Module
     """
     )
@@ -1390,10 +1389,8 @@ def test_customize_through_attributes(testdir):
         import pytest
         class MyFunction(pytest.Function):
             pass
-        class MyInstance(pytest.Instance):
-            Function = MyFunction
         class MyClass(pytest.Class):
-            Instance = MyInstance
+            Function = MyFunction
 
         def pytest_pycollect_makeitem(collector, name, obj):
             if name.startswith("MyTestClass"):
@@ -1408,9 +1405,7 @@ def test_hello(self):
     """
     )
     result = testdir.runpytest("--collect-only")
-    result.stdout.fnmatch_lines(
-        ["*MyClass*", "*MyInstance*", "*MyFunction*test_hello*"]
-    )
+    result.stdout.fnmatch_lines(["*MyClass*", "*MyFunction*test_hello*"])
 
 
 def test_unorderable_types(testdir):