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

Patch by Ivan Levkivskyi.

1 files changed, 260 insertions, 0 deletions

diff --git a/Lib/test/test_tools/test_com2ann.py b/Lib/test/test_tools/test_com2ann.py
new file mode 100644
index 0000000000..2731f82ce7
--- /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()