import annotationlib
import textwrap
import types
import unittest
from test.support import run_code, check_syntax_error
class TypeAnnotationTests(unittest.TestCase):
def test_lazy_create_annotations(self):
# type objects lazy create their __annotations__ dict on demand.
# the annotations dict is stored in type.__dict__.
# a freshly created type shouldn't have an annotations dict yet.
foo = type("Foo", (), {})
for i in range(3):
self.assertFalse("__annotations__" in foo.__dict__)
d = foo.__annotations__
self.assertTrue("__annotations__" in foo.__dict__)
self.assertEqual(foo.__annotations__, d)
self.assertEqual(foo.__dict__['__annotations__'], d)
del foo.__annotations__
def test_setting_annotations(self):
foo = type("Foo", (), {})
for i in range(3):
self.assertFalse("__annotations__" in foo.__dict__)
d = {'a': int}
foo.__annotations__ = d
self.assertTrue("__annotations__" in foo.__dict__)
self.assertEqual(foo.__annotations__, d)
self.assertEqual(foo.__dict__['__annotations__'], d)
del foo.__annotations__
def test_annotations_getset_raises(self):
# builtin types don't have __annotations__ (yet!)
with self.assertRaises(AttributeError):
print(float.__annotations__)
with self.assertRaises(TypeError):
float.__annotations__ = {}
with self.assertRaises(TypeError):
del float.__annotations__
# double delete
foo = type("Foo", (), {})
foo.__annotations__ = {}
del foo.__annotations__
with self.assertRaises(AttributeError):
del foo.__annotations__
def test_annotations_are_created_correctly(self):
class C:
a:int=3
b:str=4
self.assertEqual(C.__annotations__, {"a": int, "b": str})
self.assertTrue("__annotations__" in C.__dict__)
del C.__annotations__
self.assertFalse("__annotations__" in C.__dict__)
def test_descriptor_still_works(self):
class C:
def __init__(self, name=None, bases=None, d=None):
self.my_annotations = None
@property
def __annotations__(self):
if not hasattr(self, 'my_annotations'):
self.my_annotations = {}
if not isinstance(self.my_annotations, dict):
self.my_annotations = {}
return self.my_annotations
@__annotations__.setter
def __annotations__(self, value):
if not isinstance(value, dict):
raise ValueError("can only set __annotations__ to a dict")
self.my_annotations = value
@__annotations__.deleter
def __annotations__(self):
if getattr(self, 'my_annotations', False) is None:
raise AttributeError('__annotations__')
self.my_annotations = None
c = C()
self.assertEqual(c.__annotations__, {})
d = {'a':'int'}
c.__annotations__ = d
self.assertEqual(c.__annotations__, d)
with self.assertRaises(ValueError):
c.__annotations__ = 123
del c.__annotations__
with self.assertRaises(AttributeError):
del c.__annotations__
self.assertEqual(c.__annotations__, {})
class D(metaclass=C):
pass
self.assertEqual(D.__annotations__, {})
d = {'a':'int'}
D.__annotations__ = d
self.assertEqual(D.__annotations__, d)
with self.assertRaises(ValueError):
D.__annotations__ = 123
del D.__annotations__
with self.assertRaises(AttributeError):
del D.__annotations__
self.assertEqual(D.__annotations__, {})
def build_module(code: str, name: str = "top") -> types.ModuleType:
ns = run_code(code)
mod = types.ModuleType(name)
mod.__dict__.update(ns)
return mod
class TestSetupAnnotations(unittest.TestCase):
def check(self, code: str):
code = textwrap.dedent(code)
for scope in ("module", "class"):
with self.subTest(scope=scope):
if scope == "class":
code = f"class C:\n{textwrap.indent(code, ' ')}"
ns = run_code(code)
annotations = ns["C"].__annotations__
else:
annotations = build_module(code).__annotations__
self.assertEqual(annotations, {"x": int})
def test_top_level(self):
self.check("x: int = 1")
def test_blocks(self):
self.check("if True:\n x: int = 1")
self.check("""
while True:
x: int = 1
break
""")
self.check("""
while False:
pass
else:
x: int = 1
""")
self.check("""
for i in range(1):
x: int = 1
""")
self.check("""
for i in range(1):
pass
else:
x: int = 1
""")
def test_try(self):
self.check("""
try:
x: int = 1
except:
pass
""")
self.check("""
try:
pass
except:
pass
else:
x: int = 1
""")
self.check("""
try:
pass
except:
pass
finally:
x: int = 1
""")
self.check("""
try:
1/0
except:
x: int = 1
""")
def test_try_star(self):
self.check("""
try:
x: int = 1
except* Exception:
pass
""")
self.check("""
try:
pass
except* Exception:
pass
else:
x: int = 1
""")
self.check("""
try:
pass
except* Exception:
pass
finally:
x: int = 1
""")
self.check("""
try:
1/0
except* Exception:
x: int = 1
""")
def test_match(self):
self.check("""
match 0:
case 0:
x: int = 1
""")
class AnnotateTests(unittest.TestCase):
"""See PEP 649."""
def test_manual_annotate(self):
def f():
pass
mod = types.ModuleType("mod")
class X:
pass
for obj in (f, mod, X):
with self.subTest(obj=obj):
self.check_annotations(obj)
def check_annotations(self, f):
self.assertEqual(f.__annotations__, {})
self.assertIs(f.__annotate__, None)
with self.assertRaisesRegex(TypeError, "__annotate__ must be callable or None"):
f.__annotate__ = 42
f.__annotate__ = lambda: 42
with self.assertRaisesRegex(TypeError, r"takes 0 positional arguments but 1 was given"):
print(f.__annotations__)
f.__annotate__ = lambda x: 42
with self.assertRaisesRegex(TypeError, r"__annotate__ returned non-dict of type 'int'"):
print(f.__annotations__)
f.__annotate__ = lambda x: {"x": x}
self.assertEqual(f.__annotations__, {"x": 1})
# Setting annotate to None does not invalidate the cached __annotations__
f.__annotate__ = None
self.assertEqual(f.__annotations__, {"x": 1})
# But setting it to a new callable does
f.__annotate__ = lambda x: {"y": x}
self.assertEqual(f.__annotations__, {"y": 1})
# Setting f.__annotations__ also clears __annotate__
f.__annotations__ = {"z": 43}
self.assertIs(f.__annotate__, None)
class DeferredEvaluationTests(unittest.TestCase):
def test_function(self):
def func(x: undefined, /, y: undefined, *args: undefined, z: undefined, **kwargs: undefined) -> undefined:
pass
with self.assertRaises(NameError):
func.__annotations__
undefined = 1
self.assertEqual(func.__annotations__, {
"x": 1,
"y": 1,
"args": 1,
"z": 1,
"kwargs": 1,
"return": 1,
})
def test_async_function(self):
async def func(x: undefined, /, y: undefined, *args: undefined, z: undefined, **kwargs: undefined) -> undefined:
pass
with self.assertRaises(NameError):
func.__annotations__
undefined = 1
self.assertEqual(func.__annotations__, {
"x": 1,
"y": 1,
"args": 1,
"z": 1,
"kwargs": 1,
"return": 1,
})
def test_class(self):
class X:
a: undefined
with self.assertRaises(NameError):
X.__annotations__
undefined = 1
self.assertEqual(X.__annotations__, {"a": 1})
def test_module(self):
ns = run_code("x: undefined = 1")
anno = ns["__annotate__"]
with self.assertRaises(NotImplementedError):
anno(2)
with self.assertRaises(NameError):
anno(1)
ns["undefined"] = 1
self.assertEqual(anno(1), {"x": 1})
def test_class_scoping(self):
class Outer:
def meth(self, x: Nested): ...
x: Nested
class Nested: ...
self.assertEqual(Outer.meth.__annotations__, {"x": Outer.Nested})
self.assertEqual(Outer.__annotations__, {"x": Outer.Nested})
def test_no_exotic_expressions(self):
check_syntax_error(self, "def func(x: (yield)): ...", "yield expression cannot be used within an annotation")
check_syntax_error(self, "def func(x: (yield from x)): ...", "yield expression cannot be used within an annotation")
check_syntax_error(self, "def func(x: (y := 3)): ...", "named expression cannot be used within an annotation")
check_syntax_error(self, "def func(x: (await 42)): ...", "await expression cannot be used within an annotation")
def test_no_exotic_expressions_in_unevaluated_annotations(self):
preludes = [
"",
"class X: ",
"def f(): ",
"async def f(): ",
]
for prelude in preludes:
with self.subTest(prelude=prelude):
check_syntax_error(self, prelude + "(x): (yield)", "yield expression cannot be used within an annotation")
check_syntax_error(self, prelude + "(x): (yield from x)", "yield expression cannot be used within an annotation")
check_syntax_error(self, prelude + "(x): (y := 3)", "named expression cannot be used within an annotation")
check_syntax_error(self, prelude + "(x): (await 42)", "await expression cannot be used within an annotation")
def test_ignore_non_simple_annotations(self):
ns = run_code("class X: (y): int")
self.assertEqual(ns["X"].__annotations__, {})
ns = run_code("class X: int.b: int")
self.assertEqual(ns["X"].__annotations__, {})
ns = run_code("class X: int[str]: int")
self.assertEqual(ns["X"].__annotations__, {})
def test_generated_annotate(self):
def func(x: int):
pass
class X:
x: int
mod = build_module("x: int")
for obj in (func, X, mod):
with self.subTest(obj=obj):
annotate = obj.__annotate__
self.assertIsInstance(annotate, types.FunctionType)
self.assertEqual(annotate.__name__, "__annotate__")
with self.assertRaises(NotImplementedError):
annotate(annotationlib.Format.FORWARDREF)
with self.assertRaises(NotImplementedError):
annotate(annotationlib.Format.SOURCE)
with self.assertRaises(NotImplementedError):
annotate(None)
self.assertEqual(annotate(annotationlib.Format.VALUE), {"x": int})
def test_comprehension_in_annotation(self):
# This crashed in an earlier version of the code
ns = run_code("x: [y for y in range(10)]")
self.assertEqual(ns["__annotate__"](1), {"x": list(range(10))})
def test_future_annotations(self):
code = """
from __future__ import annotations
def f(x: int) -> int: pass
"""
ns = run_code(code)
f = ns["f"]
self.assertIsInstance(f.__annotate__, types.FunctionType)
annos = {"x": "int", "return": "int"}
self.assertEqual(f.__annotate__(annotationlib.Format.VALUE), annos)
self.assertEqual(f.__annotations__, annos)
def test_name_clash_with_format(self):
# this test would fail if __annotate__'s parameter was called "format"
code = """
class format: pass
def f(x: format): pass
"""
ns = run_code(code)
f = ns["f"]
self.assertEqual(f.__annotations__, {"x": ns["format"]})
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