Issue #27985: Implement PEP 526 -- Syntax for Variable Annotations.

Patch by Ivan Levkivskyi.

13 files changed, 743 insertions, 3 deletions

diff --git a/Lib/test/ann_module.py b/Lib/test/ann_module.py
new file mode 100644
index 0000000..9e6b87d
--- /dev/null
+++ b/Lib/test/ann_module.py
@@ -0,0 +1,53 @@
+
+
+"""
+The module for testing variable annotations.
+Empty lines above are for good reason (testing for correct line numbers)
+"""
+
+from typing import Optional
+
+__annotations__[1] = 2
+
+class C:
+
+    x = 5; y: Optional['C'] = None
+
+from typing import Tuple
+x: int = 5; y: str = x; f: Tuple[int, int]
+
+class M(type):
+
+    __annotations__['123'] = 123
+    o: type = object
+
+(pars): bool = True
+
+class D(C):
+    j: str = 'hi'; k: str= 'bye'
+
+from types import new_class
+h_class = new_class('H', (C,))
+j_class = new_class('J')
+
+class F():
+    z: int = 5
+    def __init__(self, x):
+        pass
+
+class Y(F):
+    def __init__(self):
+        super(F, self).__init__(123)
+
+class Meta(type):
+    def __new__(meta, name, bases, namespace):
+        return super().__new__(meta, name, bases, namespace)
+
+class S(metaclass = Meta):
+    x: str = 'something'
+    y: str = 'something else'
+
+def foo(x: int = 10):
+    def bar(y: List[str]):
+        x: str = 'yes'
+    bar()
diff --git a/Lib/test/ann_module2.py b/Lib/test/ann_module2.py
new file mode 100644
index 0000000..76cf5b3
--- /dev/null
+++ b/Lib/test/ann_module2.py
@@ -0,0 +1,36 @@
+"""
+Some correct syntax for variable annotation here.
+More examples are in test_grammar and test_parser.
+"""
+
+from typing import no_type_check, ClassVar
+
+i: int = 1
+j: int
+x: float = i/10
+
+def f():
+    class C: ...
+    return C()
+
+f().new_attr: object = object()
+
+class C:
+    def __init__(self, x: int) -> None:
+        self.x = x
+
+c = C(5)
+c.new_attr: int = 10
+
+__annotations__ = {}
+
+
+@no_type_check
+class NTC:
+    def meth(self, param: complex) -> None:
+        ...
+
+class CV:
+    var: ClassVar['CV']
+
+CV.var = CV()
diff --git a/Lib/test/ann_module3.py b/Lib/test/ann_module3.py
new file mode 100644
index 0000000..eccd7be
--- /dev/null
+++ b/Lib/test/ann_module3.py
@@ -0,0 +1,18 @@
+"""
+Correct syntax for variable annotation that should fail at runtime
+in a certain manner. More examples are in test_grammar and test_parser.
+"""
+
+def f_bad_ann():
+    __annotations__[1] = 2
+
+class C_OK:
+    def __init__(self, x: int) -> None:
+        self.x: no_such_name = x  # This one is OK as proposed by Guido
+
+class D_bad_ann:
+    def __init__(self, x: int) -> None:
+        sfel.y: int = 0
+
+def g_bad_ann():
+    no_such_name.attr: int = 0
diff --git a/Lib/test/pydoc_mod.py b/Lib/test/pydoc_mod.py
index cda1c9e..9c1fff5 100644
--- a/Lib/test/pydoc_mod.py
+++ b/Lib/test/pydoc_mod.py
@@ -12,7 +12,7 @@ class A:
         pass
 
 class B(object):
-    NO_MEANING = "eggs"
+    NO_MEANING: str = "eggs"
     pass
 
 class C(object):
diff --git a/Lib/test/test___all__.py b/Lib/test/test___all__.py
index e94d984..ae9114e 100644
--- a/Lib/test/test___all__.py
+++ b/Lib/test/test___all__.py
@@ -38,6 +38,8 @@ class AllTest(unittest.TestCase):
                           modname, e.__class__.__name__, e))
             if "__builtins__" in names:
                 del names["__builtins__"]
+            if '__annotations__' in names:
+                del names['__annotations__']
             keys = set(names)
             all_list = sys.modules[modname].__all__
             all_set = set(all_list)
diff --git a/Lib/test/test_dis.py b/Lib/test/test_dis.py
index 09e68ce..6081073 100644
--- a/Lib/test/test_dis.py
+++ b/Lib/test/test_dis.py
@@ -207,6 +207,38 @@ dis_simple_stmt_str = """\
              10 RETURN_VALUE
 """
 
+annot_stmt_str = """\
+
+x: int = 1
+y: fun(1)
+lst[fun(0)]: int = 1
+"""
+# leading newline is for a reason (tests lineno)
+
+dis_annot_stmt_str = """\
+  2           0 SETUP_ANNOTATIONS
+              2 LOAD_CONST               0 (1)
+              4 STORE_NAME               0 (x)
+              6 LOAD_NAME                1 (int)
+              8 STORE_ANNOTATION         0 (x)
+
+  3          10 LOAD_NAME                2 (fun)
+             12 LOAD_CONST               0 (1)
+             14 CALL_FUNCTION            1 (1 positional, 0 keyword pair)
+             16 STORE_ANNOTATION         3 (y)
+
+  4          18 LOAD_CONST               0 (1)
+             20 LOAD_NAME                4 (lst)
+             22 LOAD_NAME                2 (fun)
+             24 LOAD_CONST               1 (0)
+             26 CALL_FUNCTION            1 (1 positional, 0 keyword pair)
+             28 STORE_SUBSCR
+             30 LOAD_NAME                1 (int)
+             32 POP_TOP
+             34 LOAD_CONST               2 (None)
+             36 RETURN_VALUE
+"""
+
 compound_stmt_str = """\
 x = 0
 while 1:
@@ -345,6 +377,7 @@ class DisTests(unittest.TestCase):
     def test_disassemble_str(self):
         self.do_disassembly_test(expr_str, dis_expr_str)
         self.do_disassembly_test(simple_stmt_str, dis_simple_stmt_str)
+        self.do_disassembly_test(annot_stmt_str, dis_annot_stmt_str)
         self.do_disassembly_test(compound_stmt_str, dis_compound_stmt_str)
 
     def test_disassemble_bytes(self):
diff --git a/Lib/test/test_grammar.py b/Lib/test/test_grammar.py
index bfe5225..109013f 100644
--- a/Lib/test/test_grammar.py
+++ b/Lib/test/test_grammar.py
@@ -8,6 +8,14 @@ import sys
 # testing import *
 from sys import *
 
+# different import patterns to check that __annotations__ does not interfere
+# with import machinery
+import test.ann_module as ann_module
+import typing
+from collections import ChainMap
+from test import ann_module2
+import test
+
 
 class TokenTests(unittest.TestCase):
 
@@ -139,6 +147,19 @@ the \'lazy\' dog.\n\
                 compile(s, "<test>", "exec")
             self.assertIn("unexpected EOF", str(cm.exception))
 
+var_annot_global: int # a global annotated is necessary for test_var_annot
+
+# custom namespace for testing __annotations__
+
+class CNS:
+    def __init__(self):
+        self._dct = {}
+    def __setitem__(self, item, value):
+        self._dct[item.lower()] = value
+    def __getitem__(self, item):
+        return self._dct[item]
+
+
 class GrammarTests(unittest.TestCase):
 
     # single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE
@@ -154,6 +175,163 @@ class GrammarTests(unittest.TestCase):
         # testlist ENDMARKER
         x = eval('1, 0 or 1')
 
+    def test_var_annot_basics(self):
+        # all these should be allowed
+        var1: int = 5
+        var2: [int, str]
+        my_lst = [42]
+        def one():
+            return 1
+        int.new_attr: int
+        [list][0]: type
+        my_lst[one()-1]: int = 5
+        self.assertEqual(my_lst, [5])
+
+    def test_var_annot_syntax_errors(self):
+        # parser pass
+        check_syntax_error(self, "def f: int")
+        check_syntax_error(self, "x: int: str")
+        check_syntax_error(self, "def f():\n"
+                                 "    nonlocal x: int\n")
+        # AST pass
+        check_syntax_error(self, "[x, 0]: int\n")
+        check_syntax_error(self, "f(): int\n")
+        check_syntax_error(self, "(x,): int")
+        check_syntax_error(self, "def f():\n"
+                                 "    (x, y): int = (1, 2)\n")
+        # symtable pass
+        check_syntax_error(self, "def f():\n"
+                                 "    x: int\n"
+                                 "    global x\n")
+        check_syntax_error(self, "def f():\n"
+                                 "    global x\n"
+                                 "    x: int\n")
+
+    def test_var_annot_basic_semantics(self):
+        # execution order
+        with self.assertRaises(ZeroDivisionError):
+            no_name[does_not_exist]: no_name_again = 1/0
+        with self.assertRaises(NameError):
+            no_name[does_not_exist]: 1/0 = 0
+        global var_annot_global
+
+        # function semantics
+        def f():
+            st: str = "Hello"
+            a.b: int = (1, 2)
+            return st
+        self.assertEqual(f.__annotations__, {})
+        def f_OK():
+            x: 1/0
+        f_OK()
+        def fbad():
+            x: int
+            print(x)
+        with self.assertRaises(UnboundLocalError):
+            fbad()
+        def f2bad():
+            (no_such_global): int
+            print(no_such_global)
+        try:
+            f2bad()
+        except Exception as e:
+            self.assertIs(type(e), NameError)
+
+        # class semantics
+        class C:
+            x: int
+            s: str = "attr"
+            z = 2
+            def __init__(self, x):
+                self.x: int = x
+        self.assertEqual(C.__annotations__, {'x': int, 's': str})
+        with self.assertRaises(NameError):
+            class CBad:
+                no_such_name_defined.attr: int = 0
+        with self.assertRaises(NameError):
+            class Cbad2(C):
+                x: int
+                x.y: list = []
+
+    def test_var_annot_metaclass_semantics(self):
+        class CMeta(type):
+            @classmethod
+            def __prepare__(metacls, name, bases, **kwds):
+                return {'__annotations__': CNS()}
+        class CC(metaclass=CMeta):
+            XX: 'ANNOT'
+        self.assertEqual(CC.__annotations__['xx'], 'ANNOT')
+
+    def test_var_annot_module_semantics(self):
+        with self.assertRaises(AttributeError):
+            print(test.__annotations__)
+        self.assertEqual(ann_module.__annotations__,
+                     {1: 2, 'x': int, 'y': str, 'f': typing.Tuple[int, int]})
+        self.assertEqual(ann_module.M.__annotations__,
+                              {'123': 123, 'o': type})
+        self.assertEqual(ann_module2.__annotations__, {})
+        self.assertEqual(typing.get_type_hints(ann_module2.CV,
+                                               ann_module2.__dict__),
+                         ChainMap({'var': typing.ClassVar[ann_module2.CV]}, {}))
+
+    def test_var_annot_in_module(self):
+        # check that functions fail the same way when executed
+        # outside of module where they were defined
+        from test.ann_module3 import f_bad_ann, g_bad_ann, D_bad_ann
+        with self.assertRaises(NameError):
+            f_bad_ann()
+        with self.assertRaises(NameError):
+            g_bad_ann()
+        with self.assertRaises(NameError):
+            D_bad_ann(5)
+
+    def test_var_annot_simple_exec(self):
+        gns = {}; lns= {}
+        exec("'docstring'\n"
+             "__annotations__[1] = 2\n"
+             "x: int = 5\n", gns, lns)
+        self.assertEqual(lns["__annotations__"], {1: 2, 'x': int})
+        with self.assertRaises(KeyError):
+            gns['__annotations__']
+
+    def test_var_annot_custom_maps(self):
+        # tests with custom locals() and __annotations__
+        ns = {'__annotations__': CNS()}
+        exec('X: int; Z: str = "Z"; (w): complex = 1j', ns)
+        self.assertEqual(ns['__annotations__']['x'], int)
+        self.assertEqual(ns['__annotations__']['z'], str)
+        with self.assertRaises(KeyError):
+            ns['__annotations__']['w']
+        nonloc_ns = {}
+        class CNS2:
+            def __init__(self):
+                self._dct = {}
+            def __setitem__(self, item, value):
+                nonlocal nonloc_ns
+                self._dct[item] = value
+                nonloc_ns[item] = value
+            def __getitem__(self, item):
+                return self._dct[item]
+        exec('x: int = 1', {}, CNS2())
+        self.assertEqual(nonloc_ns['__annotations__']['x'], int)
+
+    def test_var_annot_refleak(self):
+        # complex case: custom locals plus custom __annotations__
+        # this was causing refleak
+        cns = CNS()
+        nonloc_ns = {'__annotations__': cns}
+        class CNS2:
+            def __init__(self):
+                self._dct = {'__annotations__': cns}
+            def __setitem__(self, item, value):
+                nonlocal nonloc_ns
+                self._dct[item] = value
+                nonloc_ns[item] = value
+            def __getitem__(self, item):
+                return self._dct[item]
+        exec('X: str', {}, CNS2())
+        self.assertEqual(nonloc_ns['__annotations__']['x'], str)
+
     def test_funcdef(self):
         ### [decorators] 'def' NAME parameters ['->' test] ':' suite
         ### decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
diff --git a/Lib/test/test_opcodes.py b/Lib/test/test_opcodes.py
index 6ef93d9..6806c61 100644
--- a/Lib/test/test_opcodes.py
+++ b/Lib/test/test_opcodes.py
@@ -1,6 +1,7 @@
 # Python test set -- part 2, opcodes
 
 import unittest
+from test import ann_module
 
 class OpcodeTest(unittest.TestCase):
 
@@ -20,6 +21,32 @@ class OpcodeTest(unittest.TestCase):
         if n != 90:
             self.fail('try inside for')
 
+    def test_setup_annotations_line(self):
+        # check that SETUP_ANNOTATIONS does not create spurious line numbers
+        try:
+            with open(ann_module.__file__) as f:
+                txt = f.read()
+            co = compile(txt, ann_module.__file__, 'exec')
+            self.assertEqual(co.co_firstlineno, 6)
+        except OSError:
+            pass
+
+    def test_no_annotations_if_not_needed(self):
+        class C: pass
+        with self.assertRaises(AttributeError):
+            C.__annotations__
+
+    def test_use_existing_annotations(self):
+        ns = {'__annotations__': {1: 2}}
+        exec('x: int', ns)
+        self.assertEqual(ns['__annotations__'], {'x': int, 1: 2})
+
+    def test_do_not_recreate_annotations(self):
+        class C:
+            del __annotations__
+            with self.assertRaises(NameError):
+                x: int
+
     def test_raise_class_exceptions(self):
 
         class AClass(Exception): pass
diff --git a/Lib/test/test_parser.py b/Lib/test/test_parser.py
index e2a42f9..d6e6f71 100644
--- a/Lib/test/test_parser.py
+++ b/Lib/test/test_parser.py
@@ -138,6 +138,45 @@ class RoundtripLegalSyntaxTestCase(unittest.TestCase):
         self.check_suite("a = b")
         self.check_suite("a = b = c = d = e")
 
+    def test_var_annot(self):
+        self.check_suite("x: int = 5")
+        self.check_suite("y: List[T] = []; z: [list] = fun()")
+        self.check_suite("x: tuple = (1, 2)")
+        self.check_suite("d[f()]: int = 42")
+        self.check_suite("f(d[x]): str = 'abc'")
+        self.check_suite("x.y.z.w: complex = 42j")
+        self.check_suite("x: int")
+        self.check_suite("def f():\n"
+                         "    x: str\n"
+                         "    y: int = 5\n")
+        self.check_suite("class C:\n"
+                         "    x: str\n"
+                         "    y: int = 5\n")
+        self.check_suite("class C:\n"
+                         "    def __init__(self, x: int) -> None:\n"
+                         "        self.x: int = x\n")
+        # double check for nonsense
+        with self.assertRaises(SyntaxError):
+            exec("2+2: int", {}, {})
+        with self.assertRaises(SyntaxError):
+            exec("[]: int = 5", {}, {})
+        with self.assertRaises(SyntaxError):
+            exec("x, *y, z: int = range(5)", {}, {})
+        with self.assertRaises(SyntaxError):
+            exec("t: tuple = 1, 2", {}, {})
+        with self.assertRaises(SyntaxError):
+            exec("u = v: int", {}, {})
+        with self.assertRaises(SyntaxError):
+            exec("False: int", {}, {})
+        with self.assertRaises(SyntaxError):
+            exec("x.False: int", {}, {})
+        with self.assertRaises(SyntaxError):
+            exec("x.y,: int", {}, {})
+        with self.assertRaises(SyntaxError):
+            exec("[0]: int", {}, {})
+        with self.assertRaises(SyntaxError):
+            exec("f(): int", {}, {})
+
     def test_simple_augmented_assignments(self):
         self.check_suite("a += b")
         self.check_suite("a -= b")
diff --git a/Lib/test/test_pydoc.py b/Lib/test/test_pydoc.py
index 17a82c2..5174d56 100644
--- a/Lib/test/test_pydoc.py
+++ b/Lib/test/test_pydoc.py
@@ -83,6 +83,8 @@ CLASSES
      |  Data and other attributes defined here:
      |\x20\x20
      |  NO_MEANING = 'eggs'
+     |\x20\x20
+     |  __annotations__ = {'NO_MEANING': <class 'str'>}
 \x20\x20\x20\x20
     class C(builtins.object)
      |  Methods defined here:
@@ -195,6 +197,8 @@ Data descriptors defined here:<br>
 Data and other attributes defined here:<br>
 <dl><dt><strong>NO_MEANING</strong> = 'eggs'</dl>
 
+<dl><dt><strong>__annotations__</strong> = {'NO_MEANING': &lt;class 'str'&gt;}</dl>
+
 </td></tr></table> <p>
 <table width="100%%" cellspacing=0 cellpadding=2 border=0 summary="section">
 <tr bgcolor="#ffc8d8">
diff --git a/Lib/test/test_symtable.py b/Lib/test/test_symtable.py
index bf99505..3047165 100644
--- a/Lib/test/test_symtable.py
+++ b/Lib/test/test_symtable.py
@@ -133,6 +133,17 @@ class SymtableTest(unittest.TestCase):
         self.assertTrue(self.Mine.lookup("a_method").is_assigned())
         self.assertFalse(self.internal.lookup("x").is_assigned())
 
+    def test_annotated(self):
+        st1 = symtable.symtable('def f():\n    x: int\n', 'test', 'exec')
+        st2 = st1.get_children()[0]
+        self.assertTrue(st2.lookup('x').is_local())
+        self.assertTrue(st2.lookup('x').is_annotated())
+        self.assertFalse(st2.lookup('x').is_global())
+        st3 = symtable.symtable('def f():\n    x = 1\n', 'test', 'exec')
+        st4 = st3.get_children()[0]
+        self.assertTrue(st4.lookup('x').is_local())
+        self.assertFalse(st4.lookup('x').is_annotated())
+
     def test_imported(self):
         self.assertTrue(self.top.lookup("sys").is_imported())
 
diff --git a/Lib/test/test_tools/test_com2ann.py b/Lib/test/test_tools/test_com2ann.py
new file mode 100644
index 0000000..2731f82
--- /dev/null
+++ b/Lib/test/test_tools/test_com2ann.py
@@ -0,0 +1,260 @@
+"""Tests for the com2ann.py script in the Tools/parser directory."""
+
+import unittest
+import test.support
+import os
+import re
+
+from test.test_tools import basepath, toolsdir, skip_if_missing
+
+skip_if_missing()
+
+parser_path = os.path.join(toolsdir, "parser")
+
+with test.support.DirsOnSysPath(parser_path):
+    from com2ann import *
+
+class BaseTestCase(unittest.TestCase):
+
+    def check(self, code, expected, n=False, e=False):
+        self.assertEqual(com2ann(code,
+                         drop_None=n, drop_Ellipsis=e, silent=True),
+                         expected)
+
+class SimpleTestCase(BaseTestCase):
+    # Tests for basic conversions
+
+    def test_basics(self):
+        self.check("z = 5", "z = 5")
+        self.check("z: int = 5", "z: int = 5")
+        self.check("z = 5 # type: int", "z: int = 5")
+        self.check("z = 5 # type: int # comment",
+                   "z: int = 5 # comment")
+
+    def test_type_ignore(self):
+        self.check("foobar = foobaz() #type: ignore",
+                   "foobar = foobaz() #type: ignore")
+        self.check("a = 42 #type: ignore #comment",
+                   "a = 42 #type: ignore #comment")
+
+    def test_complete_tuple(self):
+        self.check("t = 1, 2, 3 # type: Tuple[int, ...]",
+                   "t: Tuple[int, ...] = (1, 2, 3)")
+        self.check("t = 1, # type: Tuple[int]",
+                   "t: Tuple[int] = (1,)")
+        self.check("t = (1, 2, 3) # type: Tuple[int, ...]",
+                   "t: Tuple[int, ...] = (1, 2, 3)")
+
+    def test_drop_None(self):
+        self.check("x = None # type: int",
+                   "x: int", True)
+        self.check("x = None # type: int # another",
+                   "x: int # another", True)
+        self.check("x = None # type: int # None",
+                   "x: int # None", True)
+
+    def test_drop_Ellipsis(self):
+        self.check("x = ... # type: int",
+                   "x: int", False, True)
+        self.check("x = ... # type: int # another",
+                   "x: int # another", False, True)
+        self.check("x = ... # type: int # ...",
+                   "x: int # ...", False, True)
+
+    def test_newline(self):
+        self.check("z = 5 # type: int\r\n", "z: int = 5\r\n")
+        self.check("z = 5 # type: int # comment\x85",
+                   "z: int = 5 # comment\x85")
+
+    def test_wrong(self):
+        self.check("#type : str", "#type : str")
+        self.check("x==y #type: bool", "x==y #type: bool")
+
+    def test_pattern(self):
+        for line in ["#type: int", "  # type:  str[:] # com"]:
+            self.assertTrue(re.search(TYPE_COM, line))
+        for line in ["", "#", "# comment", "#type", "type int:"]:
+            self.assertFalse(re.search(TYPE_COM, line))
+
+class BigTestCase(BaseTestCase):
+    # Tests for really crazy formatting, to be sure
+    # that script works reasonably in extreme situations
+
+    def test_crazy(self):
+        self.maxDiff = None
+        self.check(crazy_code, big_result, False, False)
+        self.check(crazy_code, big_result_ne, True, True)
+
+crazy_code = """\
+# -*- coding: utf-8 -*- # this should not be spoiled
+'''
+Docstring here
+'''
+
+import testmod
+x = 5 #type    : int # this one is OK
+ttt \\
+    = \\
+        1.0, \\
+        2.0, \\
+        3.0, #type: Tuple[float, float, float]
+with foo(x==1) as f: #type: str
+    print(f)
+
+for i, j in my_inter(x=1): # type: ignore
+    i + j # type: int # what about this
+
+x = y = z = 1 # type: int
+x, y, z = [], [], []  # type: (List[int], List[int], List[str])
+class C:
+
+
+    l[f(x
+        =1)] = [
+
+         1,
+         2,
+         ]  # type: List[int]
+
+
+    (C.x[1]) = \\
+        42 == 5# type: bool
+lst[...] = \\
+    ((\\
+...)) # type: int # comment ..
+
+y = ... # type: int # comment ...
+z = ...
+#type: int
+
+
+#DONE placement of annotation after target rather than before =
+
+TD.x[1]  \\
+    = 0 == 5# type: bool
+
+TD.y[1] =5 == 5# type: bool # one more here
+F[G(x == y,
+
+# hm...
+
+    z)]\\
+      = None # type: OMG[int] # comment: None
+x = None#type:int   #comment : None"""
+
+big_result = """\
+# -*- coding: utf-8 -*- # this should not be spoiled
+'''
+Docstring here
+'''
+
+import testmod
+x: int = 5 # this one is OK
+ttt: Tuple[float, float, float] \\
+    = \\
+       (1.0, \\
+        2.0, \\
+        3.0,)
+with foo(x==1) as f: #type: str
+    print(f)
+
+for i, j in my_inter(x=1): # type: ignore
+    i + j # type: int # what about this
+
+x = y = z = 1 # type: int
+x, y, z = [], [], []  # type: (List[int], List[int], List[str])
+class C:
+
+
+    l[f(x
+        =1)]: List[int] = [
+
+         1,
+         2,
+         ]
+
+
+    (C.x[1]): bool = \\
+        42 == 5
+lst[...]: int = \\
+    ((\\
+...)) # comment ..
+
+y: int = ... # comment ...
+z = ...
+#type: int
+
+
+#DONE placement of annotation after target rather than before =
+
+TD.x[1]: bool  \\
+    = 0 == 5
+
+TD.y[1]: bool =5 == 5 # one more here
+F[G(x == y,
+
+# hm...
+
+    z)]: OMG[int]\\
+      = None # comment: None
+x: int = None   #comment : None"""
+
+big_result_ne = """\
+# -*- coding: utf-8 -*- # this should not be spoiled
+'''
+Docstring here
+'''
+
+import testmod
+x: int = 5 # this one is OK
+ttt: Tuple[float, float, float] \\
+    = \\
+       (1.0, \\
+        2.0, \\
+        3.0,)
+with foo(x==1) as f: #type: str
+    print(f)
+
+for i, j in my_inter(x=1): # type: ignore
+    i + j # type: int # what about this
+
+x = y = z = 1 # type: int
+x, y, z = [], [], []  # type: (List[int], List[int], List[str])
+class C:
+
+
+    l[f(x
+        =1)]: List[int] = [
+
+         1,
+         2,
+         ]
+
+
+    (C.x[1]): bool = \\
+        42 == 5
+lst[...]: int \\
+    \\
+ # comment ..
+
+y: int # comment ...
+z = ...
+#type: int
+
+
+#DONE placement of annotation after target rather than before =
+
+TD.x[1]: bool  \\
+    = 0 == 5
+
+TD.y[1]: bool =5 == 5 # one more here
+F[G(x == y,
+
+# hm...
+
+    z)]: OMG[int]\\
+       # comment: None
+x: int   #comment : None"""
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py
index 72afe67..e3904b1 100644
--- a/Lib/test/test_typing.py
+++ b/Lib/test/test_typing.py
@@ -4,14 +4,16 @@ import pickle
 import re
 import sys
 from unittest import TestCase, main, skipUnless, SkipTest
+from collections import ChainMap
+from test import ann_module, ann_module2, ann_module3
 
 from typing import Any
 from typing import TypeVar, AnyStr
 from typing import T, KT, VT  # Not in __all__.
 from typing import Union, Optional
-from typing import Tuple
+from typing import Tuple, List
 from typing import Callable
-from typing import Generic
+from typing import Generic, ClassVar
 from typing import cast
 from typing import get_type_hints
 from typing import no_type_check, no_type_check_decorator
@@ -827,6 +829,43 @@ class GenericTests(BaseTestCase):
         with self.assertRaises(Exception):
             D[T]
 
+class ClassVarTests(BaseTestCase):
+
+    def test_basics(self):
+        with self.assertRaises(TypeError):
+            ClassVar[1]
+        with self.assertRaises(TypeError):
+            ClassVar[int, str]
+        with self.assertRaises(TypeError):
+            ClassVar[int][str]
+
+    def test_repr(self):
+        self.assertEqual(repr(ClassVar), 'typing.ClassVar')
+        cv = ClassVar[int]
+        self.assertEqual(repr(cv), 'typing.ClassVar[int]')
+        cv = ClassVar[Employee]
+        self.assertEqual(repr(cv), 'typing.ClassVar[%s.Employee]' % __name__)
+
+    def test_cannot_subclass(self):
+        with self.assertRaises(TypeError):
+            class C(type(ClassVar)):
+                pass
+        with self.assertRaises(TypeError):
+            class C(type(ClassVar[int])):
+                pass
+
+    def test_cannot_init(self):
+        with self.assertRaises(TypeError):
+            type(ClassVar)()
+        with self.assertRaises(TypeError):
+            type(ClassVar[Optional[int]])()
+
+    def test_no_isinstance(self):
+        with self.assertRaises(TypeError):
+            isinstance(1, ClassVar[int])
+        with self.assertRaises(TypeError):
+            issubclass(int, ClassVar)
+
 
 class VarianceTests(BaseTestCase):
 
@@ -930,6 +969,46 @@ class ForwardRefTests(BaseTestCase):
         right_hints = get_type_hints(t.add_right, globals(), locals())
         self.assertEqual(right_hints['node'], Optional[Node[T]])
 
+    def test_get_type_hints(self):
+        gth = get_type_hints
+        self.assertEqual(gth(ann_module), {'x': int, 'y': str})
+        self.assertEqual(gth(ann_module.C, ann_module.__dict__),
+                         ChainMap({'y': Optional[ann_module.C]}, {}))
+        self.assertEqual(gth(ann_module2), {})
+        self.assertEqual(gth(ann_module3), {})
+        self.assertEqual(repr(gth(ann_module.j_class)), 'ChainMap({}, {})')
+        self.assertEqual(gth(ann_module.M), ChainMap({'123': 123, 'o': type},
+                                                     {}, {}))
+        self.assertEqual(gth(ann_module.D),
+                         ChainMap({'j': str, 'k': str,
+                                   'y': Optional[ann_module.C]}, {}))
+        self.assertEqual(gth(ann_module.Y), ChainMap({'z': int}, {}))
+        self.assertEqual(gth(ann_module.h_class),
+                         ChainMap({}, {'y': Optional[ann_module.C]}, {}))
+        self.assertEqual(gth(ann_module.S), ChainMap({'x': str, 'y': str},
+                                                    {}))
+        self.assertEqual(gth(ann_module.foo), {'x': int})
+
+        def testf(x, y): ...
+        testf.__annotations__['x'] = 'int'
+        self.assertEqual(gth(testf), {'x': int})
+        self.assertEqual(gth(ann_module2.NTC.meth), {})
+
+        # interactions with ClassVar
+        class B:
+            x: ClassVar[Optional['B']] = None
+            y: int
+        class C(B):
+            z: ClassVar['C'] = B()
+        class G(Generic[T]):
+            lst: ClassVar[List[T]] = []
+        self.assertEqual(gth(B, locals()),
+                         ChainMap({'y': int, 'x': ClassVar[Optional[B]]}, {}))
+        self.assertEqual(gth(C, locals()),
+                        ChainMap({'z': ClassVar[C]},
+                                 {'y': int, 'x': ClassVar[Optional[B]]}, {}))
+        self.assertEqual(gth(G), ChainMap({'lst': ClassVar[List[T]]},{},{}))
+
     def test_forwardref_instance_type_error(self):
         fr = typing._ForwardRef('int')
         with self.assertRaises(TypeError):