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"""Tests for undefined variable with assignment expressions"""
# pylint: disable=using-constant-test, expression-not-assigned
# Tests for annotation of variables and potentially undefinition
from typing import TYPE_CHECKING
def typing_and_assignment_expression():
"""The variable gets assigned in an assignment expression"""
var: int
if (var := 1 ** 2):
print(var)
def typing_and_self_referencing_assignment_expression():
"""The variable gets assigned in an assignment expression that references itself"""
var: int
if (var := var ** 2): # [used-before-assignment]
print(var)
def self_referencing_assignment_expression():
"""An invalid self-referencing assignment expression"""
if (var := var()): # [used-before-assignment]
print(var)
def typed_assignment_in_function_default(param: str = (typed_default := "walrus")) -> None:
"""An annotated assignment expression in a default parameter should not emit"""
return param
print(typed_default)
def assignment_in_function_default(param = (default := "walrus")) -> None:
"""An assignment expression in a default parameter should not emit"""
return param
print(default)
def no_assignment_in_function_default(param: str = "walrus") -> None:
"""No annotated assignment expression should emit"""
return param
print(no_default) # [undefined-variable]
def no_parameters_in_function_default() -> None:
"""Regression tests for functions without any parameters"""
return
print(again_no_default) # [undefined-variable]
# Tests for assignment expressions in if ... else comprehensions
[i for i in range(10) if (if_assign_1 := i)]
print(if_assign_1)
IF_TWO = [i for i in range(10) if (if_assign_2 := i)]
print(if_assign_2)
IF_THREE = next(i for i in range(10) if (if_assign_3 := i))
print(if_assign_3)
IF_FOUR = {i: i for i in range(10) if (if_assign_4 := i)}
print(if_assign_4)
IF_FIVE = {i: i if (if_assign_5 := i) else 0 for i in range(10)}
print(if_assign_5)
{i: i if True else (else_assign_1 := i) for i in range(10)}
print(else_assign_1) # [undefined-variable]
# Tests for assignment expressions in the assignment of comprehensions
[(assign_assign_1 := i) for i in range(10)]
print(assign_assign_1)
COMPREHENSION_TWO =[(assign_assign_2 := i) for i in range(10)]
print(assign_assign_2)
COMPREHENSION_THREE = next((assign_assign_3 := i) for i in range(10))
print(assign_assign_3)
COMPREHENSION_FOUR = {i: (assign_assign_4 := i) for i in range(10)}
print(assign_assign_4)
COMPREHENSION_FIVE = {i: (else_assign_2 := i) if False else 0 for i in range(10)}
print(else_assign_2) # [undefined-variable]
# Tests for assignment expressions in lambda statements
things = []
sorted_things = sorted(
things,
key=lambda thing: x_0
if (x_0 := thing.this_value) < (x_1 := thing.that_value)
else x_1,
)
# Tests for type annotation reused in comprehension
def type_annotation_used_after_comprehension():
"""https://github.com/pylint-dev/pylint/issues/5326#issuecomment-982635371"""
my_int: int
ints = [my_int + 1 for my_int in range(5)]
for my_int in ints:
print(my_int)
def type_annotation_unused_after_comprehension():
"""https://github.com/pylint-dev/pylint/issues/5326"""
my_int: int
_ = [print(sep=my_int, end=my_int) for my_int in range(10)]
def type_annotation_used_improperly_after_comprehension():
"""https://github.com/pylint-dev/pylint/issues/5654"""
my_int: int
_ = [print(sep=my_int, end=my_int) for my_int in range(10)]
print(my_int) # [used-before-assignment]
def type_annotation_used_improperly_after_comprehension_2():
"""Same case as above but with positional arguments"""
my_int: int
_ = [print(my_int, my_int) for my_int in range(10)]
print(my_int) # [used-before-assignment]
# Tests for named expressions (walrus operator)
# Expression in ternary operator: positional argument
print(sep=colon if (colon := ":") else None)
class Dummy:
"""Expression in ternary operator: keyword argument"""
# pylint: disable=too-few-public-methods
def __init__(self, value):
self.value = value
dummy = Dummy(value=val if (val := 'something') else 'anything')
def expression_in_ternary_operator_inside_container():
"""Named expression in ternary operator: inside container"""
return [val2 if (val2 := 'something') else 'anything']
def expression_in_ternary_operator_inside_container_tuple():
"""Same case, using a tuple inside a 1-element list"""
return [(val3, val3) if (val3 := 'something') else 'anything']
def expression_in_ternary_operator_inside_container_later_position():
"""
Named expression follows unrelated item in container.
If 23 is replaced with `val3`, there is currently a false negative,
but the false positive here is more important and likely to occur."""
return [23, val3 if (val3 := 'something') else 'anything']
# Self-referencing
if (z := z): # [used-before-assignment]
z = z + 1
if (defined := False):
NEVER_DEFINED = 1
print(defined)
print(NEVER_DEFINED) # [used-before-assignment]
if (still_defined := False) == 1:
NEVER_DEFINED_EITHER = 1
print(still_defined)
if TYPE_CHECKING:
import enum
import weakref
elif input():
if input() + 1:
pass
elif (enum := None):
pass
else:
print(None if (weakref := '') else True)
else:
pass
def defined_by_walrus_in_type_checking() -> weakref:
"""Usage of variables defined in TYPE_CHECKING blocks"""
print(enum)
return weakref
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