Current File : //opt/cloudlinux/venv/lib/python3.11/site-packages/pyflakes/test/test_other.py
"""
Tests for various Pyflakes behavior.
"""
from sys import version_info
from pyflakes import messages as m
from pyflakes.test.harness import TestCase, skip, skipIf
class Test(TestCase):
def test_duplicateArgs(self):
self.flakes('def fu(bar, bar): pass', m.DuplicateArgument)
def test_localReferencedBeforeAssignment(self):
self.flakes('''
a = 1
def f():
a; a=1
f()
''', m.UndefinedLocal, m.UnusedVariable)
def test_redefinedInGenerator(self):
"""
Test that reusing a variable in a generator does not raise
a warning.
"""
self.flakes('''
a = 1
(1 for a, b in [(1, 2)])
''')
self.flakes('''
class A:
a = 1
list(1 for a, b in [(1, 2)])
''')
self.flakes('''
def f():
a = 1
(1 for a, b in [(1, 2)])
''', m.UnusedVariable)
self.flakes('''
(1 for a, b in [(1, 2)])
(1 for a, b in [(1, 2)])
''')
self.flakes('''
for a, b in [(1, 2)]:
pass
(1 for a, b in [(1, 2)])
''')
def test_redefinedInSetComprehension(self):
"""
Test that reusing a variable in a set comprehension does not raise
a warning.
"""
self.flakes('''
a = 1
{1 for a, b in [(1, 2)]}
''')
self.flakes('''
class A:
a = 1
{1 for a, b in [(1, 2)]}
''')
self.flakes('''
def f():
a = 1
{1 for a, b in [(1, 2)]}
''', m.UnusedVariable)
self.flakes('''
{1 for a, b in [(1, 2)]}
{1 for a, b in [(1, 2)]}
''')
self.flakes('''
for a, b in [(1, 2)]:
pass
{1 for a, b in [(1, 2)]}
''')
def test_redefinedInDictComprehension(self):
"""
Test that reusing a variable in a dict comprehension does not raise
a warning.
"""
self.flakes('''
a = 1
{1: 42 for a, b in [(1, 2)]}
''')
self.flakes('''
class A:
a = 1
{1: 42 for a, b in [(1, 2)]}
''')
self.flakes('''
def f():
a = 1
{1: 42 for a, b in [(1, 2)]}
''', m.UnusedVariable)
self.flakes('''
{1: 42 for a, b in [(1, 2)]}
{1: 42 for a, b in [(1, 2)]}
''')
self.flakes('''
for a, b in [(1, 2)]:
pass
{1: 42 for a, b in [(1, 2)]}
''')
def test_redefinedFunction(self):
"""
Test that shadowing a function definition with another one raises a
warning.
"""
self.flakes('''
def a(): pass
def a(): pass
''', m.RedefinedWhileUnused)
def test_redefinedUnderscoreFunction(self):
"""
Test that shadowing a function definition named with underscore doesn't
raise anything.
"""
self.flakes('''
def _(): pass
def _(): pass
''')
def test_redefinedUnderscoreImportation(self):
"""
Test that shadowing an underscore importation raises a warning.
"""
self.flakes('''
from .i18n import _
def _(): pass
''', m.RedefinedWhileUnused)
def test_redefinedClassFunction(self):
"""
Test that shadowing a function definition in a class suite with another
one raises a warning.
"""
self.flakes('''
class A:
def a(): pass
def a(): pass
''', m.RedefinedWhileUnused)
def test_redefinedIfElseFunction(self):
"""
Test that shadowing a function definition twice in an if
and else block does not raise a warning.
"""
self.flakes('''
if True:
def a(): pass
else:
def a(): pass
''')
def test_redefinedIfFunction(self):
"""
Test that shadowing a function definition within an if block
raises a warning.
"""
self.flakes('''
if True:
def a(): pass
def a(): pass
''', m.RedefinedWhileUnused)
def test_redefinedTryExceptFunction(self):
"""
Test that shadowing a function definition twice in try
and except block does not raise a warning.
"""
self.flakes('''
try:
def a(): pass
except:
def a(): pass
''')
def test_redefinedTryFunction(self):
"""
Test that shadowing a function definition within a try block
raises a warning.
"""
self.flakes('''
try:
def a(): pass
def a(): pass
except:
pass
''', m.RedefinedWhileUnused)
def test_redefinedIfElseInListComp(self):
"""
Test that shadowing a variable in a list comprehension in
an if and else block does not raise a warning.
"""
self.flakes('''
if False:
a = 1
else:
[a for a in '12']
''')
def test_functionDecorator(self):
"""
Test that shadowing a function definition with a decorated version of
that function does not raise a warning.
"""
self.flakes('''
from somewhere import somedecorator
def a(): pass
a = somedecorator(a)
''')
def test_classFunctionDecorator(self):
"""
Test that shadowing a function definition in a class suite with a
decorated version of that function does not raise a warning.
"""
self.flakes('''
class A:
def a(): pass
a = classmethod(a)
''')
def test_modernProperty(self):
self.flakes("""
class A:
@property
def t(self):
pass
@t.setter
def t(self, value):
pass
@t.deleter
def t(self):
pass
""")
def test_unaryPlus(self):
"""Don't die on unary +."""
self.flakes('+1')
def test_undefinedBaseClass(self):
"""
If a name in the base list of a class definition is undefined, a
warning is emitted.
"""
self.flakes('''
class foo(foo):
pass
''', m.UndefinedName)
def test_classNameUndefinedInClassBody(self):
"""
If a class name is used in the body of that class's definition and
the name is not already defined, a warning is emitted.
"""
self.flakes('''
class foo:
foo
''', m.UndefinedName)
def test_classNameDefinedPreviously(self):
"""
If a class name is used in the body of that class's definition and
the name was previously defined in some other way, no warning is
emitted.
"""
self.flakes('''
foo = None
class foo:
foo
''')
def test_classRedefinition(self):
"""
If a class is defined twice in the same module, a warning is emitted.
"""
self.flakes('''
class Foo:
pass
class Foo:
pass
''', m.RedefinedWhileUnused)
def test_functionRedefinedAsClass(self):
"""
If a function is redefined as a class, a warning is emitted.
"""
self.flakes('''
def Foo():
pass
class Foo:
pass
''', m.RedefinedWhileUnused)
def test_classRedefinedAsFunction(self):
"""
If a class is redefined as a function, a warning is emitted.
"""
self.flakes('''
class Foo:
pass
def Foo():
pass
''', m.RedefinedWhileUnused)
def test_classWithReturn(self):
"""
If a return is used inside a class, a warning is emitted.
"""
self.flakes('''
class Foo(object):
return
''', m.ReturnOutsideFunction)
def test_moduleWithReturn(self):
"""
If a return is used at the module level, a warning is emitted.
"""
self.flakes('''
return
''', m.ReturnOutsideFunction)
def test_classWithYield(self):
"""
If a yield is used inside a class, a warning is emitted.
"""
self.flakes('''
class Foo(object):
yield
''', m.YieldOutsideFunction)
def test_moduleWithYield(self):
"""
If a yield is used at the module level, a warning is emitted.
"""
self.flakes('''
yield
''', m.YieldOutsideFunction)
def test_classWithYieldFrom(self):
"""
If a yield from is used inside a class, a warning is emitted.
"""
self.flakes('''
class Foo(object):
yield from range(10)
''', m.YieldOutsideFunction)
def test_moduleWithYieldFrom(self):
"""
If a yield from is used at the module level, a warning is emitted.
"""
self.flakes('''
yield from range(10)
''', m.YieldOutsideFunction)
def test_continueOutsideLoop(self):
self.flakes('''
continue
''', m.ContinueOutsideLoop)
self.flakes('''
def f():
continue
''', m.ContinueOutsideLoop)
self.flakes('''
while True:
pass
else:
continue
''', m.ContinueOutsideLoop)
self.flakes('''
while True:
pass
else:
if 1:
if 2:
continue
''', m.ContinueOutsideLoop)
self.flakes('''
while True:
def f():
continue
''', m.ContinueOutsideLoop)
self.flakes('''
while True:
class A:
continue
''', m.ContinueOutsideLoop)
def test_continueInsideLoop(self):
self.flakes('''
while True:
continue
''')
self.flakes('''
for i in range(10):
continue
''')
self.flakes('''
while True:
if 1:
continue
''')
self.flakes('''
for i in range(10):
if 1:
continue
''')
self.flakes('''
while True:
while True:
pass
else:
continue
else:
pass
''')
self.flakes('''
while True:
try:
pass
finally:
while True:
continue
''')
@skipIf(version_info > (3, 8), "Python <= 3.8 only")
def test_continueInFinally(self):
# 'continue' inside 'finally' is a special syntax error
# that is removed in 3.8
self.flakes('''
while True:
try:
pass
finally:
continue
''', m.ContinueInFinally)
self.flakes('''
while True:
try:
pass
finally:
if 1:
if 2:
continue
''', m.ContinueInFinally)
# Even when not in a loop, this is the error Python gives
self.flakes('''
try:
pass
finally:
continue
''', m.ContinueInFinally)
def test_breakOutsideLoop(self):
self.flakes('''
break
''', m.BreakOutsideLoop)
self.flakes('''
def f():
break
''', m.BreakOutsideLoop)
self.flakes('''
while True:
pass
else:
break
''', m.BreakOutsideLoop)
self.flakes('''
while True:
pass
else:
if 1:
if 2:
break
''', m.BreakOutsideLoop)
self.flakes('''
while True:
def f():
break
''', m.BreakOutsideLoop)
self.flakes('''
while True:
class A:
break
''', m.BreakOutsideLoop)
self.flakes('''
try:
pass
finally:
break
''', m.BreakOutsideLoop)
def test_breakInsideLoop(self):
self.flakes('''
while True:
break
''')
self.flakes('''
for i in range(10):
break
''')
self.flakes('''
while True:
if 1:
break
''')
self.flakes('''
for i in range(10):
if 1:
break
''')
self.flakes('''
while True:
while True:
pass
else:
break
else:
pass
''')
self.flakes('''
while True:
try:
pass
finally:
while True:
break
''')
self.flakes('''
while True:
try:
pass
finally:
break
''')
self.flakes('''
while True:
try:
pass
finally:
if 1:
if 2:
break
''')
def test_defaultExceptLast(self):
"""
A default except block should be last.
YES:
try:
...
except Exception:
...
except:
...
NO:
try:
...
except:
...
except Exception:
...
"""
self.flakes('''
try:
pass
except ValueError:
pass
''')
self.flakes('''
try:
pass
except ValueError:
pass
except:
pass
''')
self.flakes('''
try:
pass
except:
pass
''')
self.flakes('''
try:
pass
except ValueError:
pass
else:
pass
''')
self.flakes('''
try:
pass
except:
pass
else:
pass
''')
self.flakes('''
try:
pass
except ValueError:
pass
except:
pass
else:
pass
''')
def test_defaultExceptNotLast(self):
self.flakes('''
try:
pass
except:
pass
except ValueError:
pass
''', m.DefaultExceptNotLast)
self.flakes('''
try:
pass
except:
pass
except:
pass
''', m.DefaultExceptNotLast)
self.flakes('''
try:
pass
except:
pass
except ValueError:
pass
except:
pass
''', m.DefaultExceptNotLast)
self.flakes('''
try:
pass
except:
pass
except ValueError:
pass
except:
pass
except ValueError:
pass
''', m.DefaultExceptNotLast, m.DefaultExceptNotLast)
self.flakes('''
try:
pass
except:
pass
except ValueError:
pass
else:
pass
''', m.DefaultExceptNotLast)
self.flakes('''
try:
pass
except:
pass
except:
pass
else:
pass
''', m.DefaultExceptNotLast)
self.flakes('''
try:
pass
except:
pass
except ValueError:
pass
except:
pass
else:
pass
''', m.DefaultExceptNotLast)
self.flakes('''
try:
pass
except:
pass
except ValueError:
pass
except:
pass
except ValueError:
pass
else:
pass
''', m.DefaultExceptNotLast, m.DefaultExceptNotLast)
self.flakes('''
try:
pass
except:
pass
except ValueError:
pass
finally:
pass
''', m.DefaultExceptNotLast)
self.flakes('''
try:
pass
except:
pass
except:
pass
finally:
pass
''', m.DefaultExceptNotLast)
self.flakes('''
try:
pass
except:
pass
except ValueError:
pass
except:
pass
finally:
pass
''', m.DefaultExceptNotLast)
self.flakes('''
try:
pass
except:
pass
except ValueError:
pass
except:
pass
except ValueError:
pass
finally:
pass
''', m.DefaultExceptNotLast, m.DefaultExceptNotLast)
self.flakes('''
try:
pass
except:
pass
except ValueError:
pass
else:
pass
finally:
pass
''', m.DefaultExceptNotLast)
self.flakes('''
try:
pass
except:
pass
except:
pass
else:
pass
finally:
pass
''', m.DefaultExceptNotLast)
self.flakes('''
try:
pass
except:
pass
except ValueError:
pass
except:
pass
else:
pass
finally:
pass
''', m.DefaultExceptNotLast)
self.flakes('''
try:
pass
except:
pass
except ValueError:
pass
except:
pass
except ValueError:
pass
else:
pass
finally:
pass
''', m.DefaultExceptNotLast, m.DefaultExceptNotLast)
def test_starredAssignmentNoError(self):
"""
Python 3 extended iterable unpacking
"""
self.flakes('''
a, *b = range(10)
''')
self.flakes('''
*a, b = range(10)
''')
self.flakes('''
a, *b, c = range(10)
''')
self.flakes('''
(a, *b) = range(10)
''')
self.flakes('''
(*a, b) = range(10)
''')
self.flakes('''
(a, *b, c) = range(10)
''')
self.flakes('''
[a, *b] = range(10)
''')
self.flakes('''
[*a, b] = range(10)
''')
self.flakes('''
[a, *b, c] = range(10)
''')
# Taken from test_unpack_ex.py in the cPython source
s = ", ".join("a%d" % i for i in range(1 << 8 - 1)) + \
", *rest = range(1<<8)"
self.flakes(s)
s = "(" + ", ".join("a%d" % i for i in range(1 << 8 - 1)) + \
", *rest) = range(1<<8)"
self.flakes(s)
s = "[" + ", ".join("a%d" % i for i in range(1 << 8 - 1)) + \
", *rest] = range(1<<8)"
self.flakes(s)
def test_starredAssignmentErrors(self):
"""
SyntaxErrors (not encoded in the ast) surrounding Python 3 extended
iterable unpacking
"""
# Taken from test_unpack_ex.py in the cPython source
s = ", ".join("a%d" % i for i in range(1 << 8)) + \
", *rest = range(1<<8 + 1)"
self.flakes(s, m.TooManyExpressionsInStarredAssignment)
s = "(" + ", ".join("a%d" % i for i in range(1 << 8)) + \
", *rest) = range(1<<8 + 1)"
self.flakes(s, m.TooManyExpressionsInStarredAssignment)
s = "[" + ", ".join("a%d" % i for i in range(1 << 8)) + \
", *rest] = range(1<<8 + 1)"
self.flakes(s, m.TooManyExpressionsInStarredAssignment)
s = ", ".join("a%d" % i for i in range(1 << 8 + 1)) + \
", *rest = range(1<<8 + 2)"
self.flakes(s, m.TooManyExpressionsInStarredAssignment)
s = "(" + ", ".join("a%d" % i for i in range(1 << 8 + 1)) + \
", *rest) = range(1<<8 + 2)"
self.flakes(s, m.TooManyExpressionsInStarredAssignment)
s = "[" + ", ".join("a%d" % i for i in range(1 << 8 + 1)) + \
", *rest] = range(1<<8 + 2)"
self.flakes(s, m.TooManyExpressionsInStarredAssignment)
# No way we can actually test this!
# s = "*rest, " + ", ".join("a%d" % i for i in range(1<<24)) + \
# ", *rest = range(1<<24 + 1)"
# self.flakes(s, m.TooManyExpressionsInStarredAssignment)
self.flakes('''
a, *b, *c = range(10)
''', m.TwoStarredExpressions)
self.flakes('''
a, *b, c, *d = range(10)
''', m.TwoStarredExpressions)
self.flakes('''
*a, *b, *c = range(10)
''', m.TwoStarredExpressions)
self.flakes('''
(a, *b, *c) = range(10)
''', m.TwoStarredExpressions)
self.flakes('''
(a, *b, c, *d) = range(10)
''', m.TwoStarredExpressions)
self.flakes('''
(*a, *b, *c) = range(10)
''', m.TwoStarredExpressions)
self.flakes('''
[a, *b, *c] = range(10)
''', m.TwoStarredExpressions)
self.flakes('''
[a, *b, c, *d] = range(10)
''', m.TwoStarredExpressions)
self.flakes('''
[*a, *b, *c] = range(10)
''', m.TwoStarredExpressions)
@skip("todo: Too hard to make this warn but other cases stay silent")
def test_doubleAssignment(self):
"""
If a variable is re-assigned to without being used, no warning is
emitted.
"""
self.flakes('''
x = 10
x = 20
''', m.RedefinedWhileUnused)
def test_doubleAssignmentConditionally(self):
"""
If a variable is re-assigned within a conditional, no warning is
emitted.
"""
self.flakes('''
x = 10
if True:
x = 20
''')
def test_doubleAssignmentWithUse(self):
"""
If a variable is re-assigned to after being used, no warning is
emitted.
"""
self.flakes('''
x = 10
y = x * 2
x = 20
''')
def test_comparison(self):
"""
If a defined name is used on either side of any of the six comparison
operators, no warning is emitted.
"""
self.flakes('''
x = 10
y = 20
x < y
x <= y
x == y
x != y
x >= y
x > y
''')
def test_identity(self):
"""
If a defined name is used on either side of an identity test, no
warning is emitted.
"""
self.flakes('''
x = 10
y = 20
x is y
x is not y
''')
def test_containment(self):
"""
If a defined name is used on either side of a containment test, no
warning is emitted.
"""
self.flakes('''
x = 10
y = 20
x in y
x not in y
''')
def test_loopControl(self):
"""
break and continue statements are supported.
"""
self.flakes('''
for x in [1, 2]:
break
''')
self.flakes('''
for x in [1, 2]:
continue
''')
def test_ellipsis(self):
"""
Ellipsis in a slice is supported.
"""
self.flakes('''
[1, 2][...]
''')
def test_extendedSlice(self):
"""
Extended slices are supported.
"""
self.flakes('''
x = 3
[1, 2][x,:]
''')
def test_varAugmentedAssignment(self):
"""
Augmented assignment of a variable is supported.
We don't care about var refs.
"""
self.flakes('''
foo = 0
foo += 1
''')
def test_attrAugmentedAssignment(self):
"""
Augmented assignment of attributes is supported.
We don't care about attr refs.
"""
self.flakes('''
foo = None
foo.bar += foo.baz
''')
def test_globalDeclaredInDifferentScope(self):
"""
A 'global' can be declared in one scope and reused in another.
"""
self.flakes('''
def f(): global foo
def g(): foo = 'anything'; foo.is_used()
''')
def test_function_arguments(self):
"""
Test to traverse ARG and ARGUMENT handler
"""
self.flakes('''
def foo(a, b):
pass
''')
self.flakes('''
def foo(a, b, c=0):
pass
''')
self.flakes('''
def foo(a, b, c=0, *args):
pass
''')
self.flakes('''
def foo(a, b, c=0, *args, **kwargs):
pass
''')
def test_function_arguments_python3(self):
self.flakes('''
def foo(a, b, c=0, *args, d=0, **kwargs):
pass
''')
class TestUnusedAssignment(TestCase):
"""
Tests for warning about unused assignments.
"""
def test_unusedVariable(self):
"""
Warn when a variable in a function is assigned a value that's never
used.
"""
self.flakes('''
def a():
b = 1
''', m.UnusedVariable)
def test_unusedUnderscoreVariable(self):
"""
Don't warn when the magic "_" (underscore) variable is unused.
See issue #202.
"""
self.flakes('''
def a(unused_param):
_ = unused_param
''')
def test_unusedVariableAsLocals(self):
"""
Using locals() it is perfectly valid to have unused variables
"""
self.flakes('''
def a():
b = 1
return locals()
''')
def test_unusedVariableNoLocals(self):
"""
Using locals() in wrong scope should not matter
"""
self.flakes('''
def a():
locals()
def a():
b = 1
return
''', m.UnusedVariable)
@skip("todo: Difficult because it doesn't apply in the context of a loop")
def test_unusedReassignedVariable(self):
"""
Shadowing a used variable can still raise an UnusedVariable warning.
"""
self.flakes('''
def a():
b = 1
b.foo()
b = 2
''', m.UnusedVariable)
def test_variableUsedInLoop(self):
"""
Shadowing a used variable cannot raise an UnusedVariable warning in the
context of a loop.
"""
self.flakes('''
def a():
b = True
while b:
b = False
''')
def test_assignToGlobal(self):
"""
Assigning to a global and then not using that global is perfectly
acceptable. Do not mistake it for an unused local variable.
"""
self.flakes('''
b = 0
def a():
global b
b = 1
''')
def test_assignToNonlocal(self):
"""
Assigning to a nonlocal and then not using that binding is perfectly
acceptable. Do not mistake it for an unused local variable.
"""
self.flakes('''
b = b'0'
def a():
nonlocal b
b = b'1'
''')
def test_assignToMember(self):
"""
Assigning to a member of another object and then not using that member
variable is perfectly acceptable. Do not mistake it for an unused
local variable.
"""
# XXX: Adding this test didn't generate a failure. Maybe not
# necessary?
self.flakes('''
class b:
pass
def a():
b.foo = 1
''')
def test_assignInForLoop(self):
"""
Don't warn when a variable in a for loop is assigned to but not used.
"""
self.flakes('''
def f():
for i in range(10):
pass
''')
def test_assignInListComprehension(self):
"""
Don't warn when a variable in a list comprehension is
assigned to but not used.
"""
self.flakes('''
def f():
[None for i in range(10)]
''')
def test_generatorExpression(self):
"""
Don't warn when a variable in a generator expression is
assigned to but not used.
"""
self.flakes('''
def f():
(None for i in range(10))
''')
def test_assignmentInsideLoop(self):
"""
Don't warn when a variable assignment occurs lexically after its use.
"""
self.flakes('''
def f():
x = None
for i in range(10):
if i > 2:
return x
x = i * 2
''')
def test_tupleUnpacking(self):
"""
Don't warn when a variable included in tuple unpacking is unused. It's
very common for variables in a tuple unpacking assignment to be unused
in good Python code, so warning will only create false positives.
"""
self.flakes('''
def f(tup):
(x, y) = tup
''')
self.flakes('''
def f():
(x, y) = 1, 2
''', m.UnusedVariable, m.UnusedVariable)
self.flakes('''
def f():
(x, y) = coords = 1, 2
if x > 1:
print(coords)
''')
self.flakes('''
def f():
(x, y) = coords = 1, 2
''', m.UnusedVariable)
self.flakes('''
def f():
coords = (x, y) = 1, 2
''', m.UnusedVariable)
def test_listUnpacking(self):
"""
Don't warn when a variable included in list unpacking is unused.
"""
self.flakes('''
def f(tup):
[x, y] = tup
''')
self.flakes('''
def f():
[x, y] = [1, 2]
''', m.UnusedVariable, m.UnusedVariable)
def test_closedOver(self):
"""
Don't warn when the assignment is used in an inner function.
"""
self.flakes('''
def barMaker():
foo = 5
def bar():
return foo
return bar
''')
def test_doubleClosedOver(self):
"""
Don't warn when the assignment is used in an inner function, even if
that inner function itself is in an inner function.
"""
self.flakes('''
def barMaker():
foo = 5
def bar():
def baz():
return foo
return bar
''')
def test_tracebackhideSpecialVariable(self):
"""
Do not warn about unused local variable __tracebackhide__, which is
a special variable for py.test.
"""
self.flakes("""
def helper():
__tracebackhide__ = True
""")
def test_ifexp(self):
"""
Test C{foo if bar else baz} statements.
"""
self.flakes("a = 'moo' if True else 'oink'")
self.flakes("a = foo if True else 'oink'", m.UndefinedName)
self.flakes("a = 'moo' if True else bar", m.UndefinedName)
def test_if_tuple(self):
"""
Test C{if (foo,)} conditions.
"""
self.flakes("""if (): pass""")
self.flakes("""
if (
True
):
pass
""")
self.flakes("""
if (
True,
):
pass
""", m.IfTuple)
self.flakes("""
x = 1 if (
True,
) else 2
""", m.IfTuple)
def test_withStatementNoNames(self):
"""
No warnings are emitted for using inside or after a nameless C{with}
statement a name defined beforehand.
"""
self.flakes('''
bar = None
with open("foo"):
bar
bar
''')
def test_withStatementSingleName(self):
"""
No warnings are emitted for using a name defined by a C{with} statement
within the suite or afterwards.
"""
self.flakes('''
with open('foo') as bar:
bar
bar
''')
def test_withStatementAttributeName(self):
"""
No warnings are emitted for using an attribute as the target of a
C{with} statement.
"""
self.flakes('''
import foo
with open('foo') as foo.bar:
pass
''')
def test_withStatementSubscript(self):
"""
No warnings are emitted for using a subscript as the target of a
C{with} statement.
"""
self.flakes('''
import foo
with open('foo') as foo[0]:
pass
''')
def test_withStatementSubscriptUndefined(self):
"""
An undefined name warning is emitted if the subscript used as the
target of a C{with} statement is not defined.
"""
self.flakes('''
import foo
with open('foo') as foo[bar]:
pass
''', m.UndefinedName)
def test_withStatementTupleNames(self):
"""
No warnings are emitted for using any of the tuple of names defined by
a C{with} statement within the suite or afterwards.
"""
self.flakes('''
with open('foo') as (bar, baz):
bar, baz
bar, baz
''')
def test_withStatementListNames(self):
"""
No warnings are emitted for using any of the list of names defined by a
C{with} statement within the suite or afterwards.
"""
self.flakes('''
with open('foo') as [bar, baz]:
bar, baz
bar, baz
''')
def test_withStatementComplicatedTarget(self):
"""
If the target of a C{with} statement uses any or all of the valid forms
for that part of the grammar (See
U{http://docs.python.org/reference/compound_stmts.html#the-with-statement}),
the names involved are checked both for definedness and any bindings
created are respected in the suite of the statement and afterwards.
"""
self.flakes('''
c = d = e = g = h = i = None
with open('foo') as [(a, b), c[d], e.f, g[h:i]]:
a, b, c, d, e, g, h, i
a, b, c, d, e, g, h, i
''')
def test_withStatementSingleNameUndefined(self):
"""
An undefined name warning is emitted if the name first defined by a
C{with} statement is used before the C{with} statement.
"""
self.flakes('''
bar
with open('foo') as bar:
pass
''', m.UndefinedName)
def test_withStatementTupleNamesUndefined(self):
"""
An undefined name warning is emitted if a name first defined by the
tuple-unpacking form of the C{with} statement is used before the
C{with} statement.
"""
self.flakes('''
baz
with open('foo') as (bar, baz):
pass
''', m.UndefinedName)
def test_withStatementSingleNameRedefined(self):
"""
A redefined name warning is emitted if a name bound by an import is
rebound by the name defined by a C{with} statement.
"""
self.flakes('''
import bar
with open('foo') as bar:
pass
''', m.RedefinedWhileUnused)
def test_withStatementTupleNamesRedefined(self):
"""
A redefined name warning is emitted if a name bound by an import is
rebound by one of the names defined by the tuple-unpacking form of a
C{with} statement.
"""
self.flakes('''
import bar
with open('foo') as (bar, baz):
pass
''', m.RedefinedWhileUnused)
def test_withStatementUndefinedInside(self):
"""
An undefined name warning is emitted if a name is used inside the
body of a C{with} statement without first being bound.
"""
self.flakes('''
with open('foo') as bar:
baz
''', m.UndefinedName)
def test_withStatementNameDefinedInBody(self):
"""
A name defined in the body of a C{with} statement can be used after
the body ends without warning.
"""
self.flakes('''
with open('foo') as bar:
baz = 10
baz
''')
def test_withStatementUndefinedInExpression(self):
"""
An undefined name warning is emitted if a name in the I{test}
expression of a C{with} statement is undefined.
"""
self.flakes('''
with bar as baz:
pass
''', m.UndefinedName)
self.flakes('''
with bar as bar:
pass
''', m.UndefinedName)
def test_dictComprehension(self):
"""
Dict comprehensions are properly handled.
"""
self.flakes('''
a = {1: x for x in range(10)}
''')
def test_setComprehensionAndLiteral(self):
"""
Set comprehensions are properly handled.
"""
self.flakes('''
a = {1, 2, 3}
b = {x for x in range(10)}
''')
def test_exceptionUsedInExcept(self):
self.flakes('''
try: pass
except Exception as e: e
''')
self.flakes('''
def download_review():
try: pass
except Exception as e: e
''')
def test_exceptionUnusedInExcept(self):
self.flakes('''
try: pass
except Exception as e: pass
''', m.UnusedVariable)
@skipIf(version_info < (3, 11), 'new in Python 3.11')
def test_exception_unused_in_except_star(self):
self.flakes('''
try:
pass
except* OSError as e:
pass
''', m.UnusedVariable)
def test_exceptionUnusedInExceptInFunction(self):
self.flakes('''
def download_review():
try: pass
except Exception as e: pass
''', m.UnusedVariable)
def test_exceptWithoutNameInFunction(self):
"""
Don't issue false warning when an unnamed exception is used.
Previously, there would be a false warning, but only when the
try..except was in a function
"""
self.flakes('''
import tokenize
def foo():
try: pass
except tokenize.TokenError: pass
''')
def test_exceptWithoutNameInFunctionTuple(self):
"""
Don't issue false warning when an unnamed exception is used.
This example catches a tuple of exception types.
"""
self.flakes('''
import tokenize
def foo():
try: pass
except (tokenize.TokenError, IndentationError): pass
''')
def test_augmentedAssignmentImportedFunctionCall(self):
"""
Consider a function that is called on the right part of an
augassign operation to be used.
"""
self.flakes('''
from foo import bar
baz = 0
baz += bar()
''')
def test_assert_without_message(self):
"""An assert without a message is not an error."""
self.flakes('''
a = 1
assert a
''')
def test_assert_with_message(self):
"""An assert with a message is not an error."""
self.flakes('''
a = 1
assert a, 'x'
''')
def test_assert_tuple(self):
"""An assert of a non-empty tuple is always True."""
self.flakes('''
assert (False, 'x')
assert (False, )
''', m.AssertTuple, m.AssertTuple)
def test_assert_tuple_empty(self):
"""An assert of an empty tuple is always False."""
self.flakes('''
assert ()
''')
def test_assert_static(self):
"""An assert of a static value is not an error."""
self.flakes('''
assert True
assert 1
''')
def test_yieldFromUndefined(self):
"""
Test C{yield from} statement
"""
self.flakes('''
def bar():
yield from foo()
''', m.UndefinedName)
def test_f_string(self):
"""Test PEP 498 f-strings are treated as a usage."""
self.flakes('''
baz = 0
print(f'\x7b4*baz\N{RIGHT CURLY BRACKET}')
''')
@skipIf(version_info < (3, 8), 'new in Python 3.8')
def test_assign_expr(self):
"""Test PEP 572 assignment expressions are treated as usage / write."""
self.flakes('''
from foo import y
print(x := y)
print(x)
''')
@skipIf(version_info < (3, 8), 'new in Python 3.8')
def test_assign_expr_generator_scope(self):
"""Test assignment expressions in generator expressions."""
self.flakes('''
if (any((y := x[0]) for x in [[True]])):
print(y)
''')
@skipIf(version_info < (3, 8), 'new in Python 3.8')
def test_assign_expr_nested(self):
"""Test assignment expressions in nested expressions."""
self.flakes('''
if ([(y:=x) for x in range(4) if [(z:=q) for q in range(4)]]):
print(y)
print(z)
''')
class TestStringFormatting(TestCase):
def test_f_string_without_placeholders(self):
self.flakes("f'foo'", m.FStringMissingPlaceholders)
self.flakes('''
f"""foo
bar
"""
''', m.FStringMissingPlaceholders)
self.flakes('''
print(
f'foo'
f'bar'
)
''', m.FStringMissingPlaceholders)
# this is an "escaped placeholder" but not a placeholder
self.flakes("f'{{}}'", m.FStringMissingPlaceholders)
# ok: f-string with placeholders
self.flakes('''
x = 5
print(f'{x}')
''')
# ok: f-string with format specifiers
self.flakes('''
x = 'a' * 90
print(f'{x:.8}')
''')
# ok: f-string with multiple format specifiers
self.flakes('''
x = y = 5
print(f'{x:>2} {y:>2}')
''')
def test_invalid_dot_format_calls(self):
self.flakes('''
'{'.format(1)
''', m.StringDotFormatInvalidFormat)
self.flakes('''
'{} {1}'.format(1, 2)
''', m.StringDotFormatMixingAutomatic)
self.flakes('''
'{0} {}'.format(1, 2)
''', m.StringDotFormatMixingAutomatic)
self.flakes('''
'{}'.format(1, 2)
''', m.StringDotFormatExtraPositionalArguments)
self.flakes('''
'{}'.format(1, bar=2)
''', m.StringDotFormatExtraNamedArguments)
self.flakes('''
'{} {}'.format(1)
''', m.StringDotFormatMissingArgument)
self.flakes('''
'{2}'.format()
''', m.StringDotFormatMissingArgument)
self.flakes('''
'{bar}'.format()
''', m.StringDotFormatMissingArgument)
# too much string recursion (placeholder-in-placeholder)
self.flakes('''
'{:{:{}}}'.format(1, 2, 3)
''', m.StringDotFormatInvalidFormat)
# ok: dotted / bracketed names need to handle the param differently
self.flakes("'{.__class__}'.format('')")
self.flakes("'{foo[bar]}'.format(foo={'bar': 'barv'})")
# ok: placeholder-placeholders
self.flakes('''
print('{:{}} {}'.format(1, 15, 2))
''')
# ok: not a placeholder-placeholder
self.flakes('''
print('{:2}'.format(1))
''')
# ok: not mixed automatic
self.flakes('''
'{foo}-{}'.format(1, foo=2)
''')
# ok: we can't determine statically the format args
self.flakes('''
a = ()
"{}".format(*a)
''')
self.flakes('''
k = {}
"{foo}".format(**k)
''')
def test_invalid_percent_format_calls(self):
self.flakes('''
'%(foo)' % {'foo': 'bar'}
''', m.PercentFormatInvalidFormat)
self.flakes('''
'%s %(foo)s' % {'foo': 'bar'}
''', m.PercentFormatMixedPositionalAndNamed)
self.flakes('''
'%(foo)s %s' % {'foo': 'bar'}
''', m.PercentFormatMixedPositionalAndNamed)
self.flakes('''
'%j' % (1,)
''', m.PercentFormatUnsupportedFormatCharacter)
self.flakes('''
'%s %s' % (1,)
''', m.PercentFormatPositionalCountMismatch)
self.flakes('''
'%s %s' % (1, 2, 3)
''', m.PercentFormatPositionalCountMismatch)
self.flakes('''
'%(bar)s' % {}
''', m.PercentFormatMissingArgument,)
self.flakes('''
'%(bar)s' % {'bar': 1, 'baz': 2}
''', m.PercentFormatExtraNamedArguments)
self.flakes('''
'%(bar)s' % (1, 2, 3)
''', m.PercentFormatExpectedMapping)
self.flakes('''
'%s %s' % {'k': 'v'}
''', m.PercentFormatExpectedSequence)
self.flakes('''
'%(bar)*s' % {'bar': 'baz'}
''', m.PercentFormatStarRequiresSequence)
# ok: single %s with mapping
self.flakes('''
'%s' % {'foo': 'bar', 'baz': 'womp'}
''')
# ok: does not cause a MemoryError (the strings aren't evaluated)
self.flakes('''
"%1000000000000f" % 1
''')
# ok: %% should not count towards placeholder count
self.flakes('''
'%% %s %% %s' % (1, 2)
''')
# ok: * consumes one positional argument
self.flakes('''
'%.*f' % (2, 1.1234)
'%*.*f' % (5, 2, 3.1234)
''')
def test_ok_percent_format_cannot_determine_element_count(self):
self.flakes('''
a = []
'%s %s' % [*a]
'%s %s' % (*a,)
''')
self.flakes('''
k = {}
'%(k)s' % {**k}
''')
class TestAsyncStatements(TestCase):
def test_asyncDef(self):
self.flakes('''
async def bar():
return 42
''')
def test_asyncDefAwait(self):
self.flakes('''
async def read_data(db):
await db.fetch('SELECT ...')
''')
def test_asyncDefUndefined(self):
self.flakes('''
async def bar():
return foo()
''', m.UndefinedName)
def test_asyncFor(self):
self.flakes('''
async def read_data(db):
output = []
async for row in db.cursor():
output.append(row)
return output
''')
def test_asyncForUnderscoreLoopVar(self):
self.flakes('''
async def coro(it):
async for _ in it:
pass
''')
def test_loopControlInAsyncFor(self):
self.flakes('''
async def read_data(db):
output = []
async for row in db.cursor():
if row[0] == 'skip':
continue
output.append(row)
return output
''')
self.flakes('''
async def read_data(db):
output = []
async for row in db.cursor():
if row[0] == 'stop':
break
output.append(row)
return output
''')
def test_loopControlInAsyncForElse(self):
self.flakes('''
async def read_data(db):
output = []
async for row in db.cursor():
output.append(row)
else:
continue
return output
''', m.ContinueOutsideLoop)
self.flakes('''
async def read_data(db):
output = []
async for row in db.cursor():
output.append(row)
else:
break
return output
''', m.BreakOutsideLoop)
@skipIf(version_info > (3, 8), "Python <= 3.8 only")
def test_continueInAsyncForFinally(self):
self.flakes('''
async def read_data(db):
output = []
async for row in db.cursor():
try:
output.append(row)
finally:
continue
return output
''', m.ContinueInFinally)
def test_asyncWith(self):
self.flakes('''
async def commit(session, data):
async with session.transaction():
await session.update(data)
''')
def test_asyncWithItem(self):
self.flakes('''
async def commit(session, data):
async with session.transaction() as trans:
await trans.begin()
...
await trans.end()
''')
def test_matmul(self):
self.flakes('''
def foo(a, b):
return a @ b
''')
def test_formatstring(self):
self.flakes('''
hi = 'hi'
mom = 'mom'
f'{hi} {mom}'
''')
def test_raise_notimplemented(self):
self.flakes('''
raise NotImplementedError("This is fine")
''')
self.flakes('''
raise NotImplementedError
''')
self.flakes('''
raise NotImplemented("This isn't gonna work")
''', m.RaiseNotImplemented)
self.flakes('''
raise NotImplemented
''', m.RaiseNotImplemented)
class TestIncompatiblePrintOperator(TestCase):
"""
Tests for warning about invalid use of print function.
"""
def test_valid_print(self):
self.flakes('''
print("Hello")
''')
def test_invalid_print_when_imported_from_future(self):
exc = self.flakes('''
from __future__ import print_function
import sys
print >>sys.stderr, "Hello"
''', m.InvalidPrintSyntax).messages[0]
self.assertEqual(exc.lineno, 4)
self.assertEqual(exc.col, 0)
def test_print_function_assignment(self):
"""
A valid assignment, tested for catching false positives.
"""
self.flakes('''
from __future__ import print_function
log = print
log("Hello")
''')
def test_print_in_lambda(self):
self.flakes('''
from __future__ import print_function
a = lambda: print
''')
def test_print_returned_in_function(self):
self.flakes('''
from __future__ import print_function
def a():
return print
''')
def test_print_as_condition_test(self):
self.flakes('''
from __future__ import print_function
if print: pass
''')