def test_message_loop_complex(self):
src = """
y = 0
x = 10
for y in range(1, 10):
x = func(y)
print(x)
x = 10
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
assign_y, assign_x1, assign_x2, assign_x3 = mod.nodes_of_class(
astroid.Assign)
self.checker.visit_module(mod)
with self.assertAddsMessages(
pylint.testutils.Message(
msg_id='redundant-assignment',
node=assign_y,
),
pylint.testutils.Message(
msg_id='redundant-assignment',
node=assign_x1,
),
):
self.checker.visit_assign(assign_y)
self.checker.visit_assign(assign_x1)
self.checker.visit_assign(assign_x2)
self.checker.visit_assign(assign_x3)
def test_message_complex(self):
src = """
def test(x):
if True:
y = 10
else:
for j in range(10):
if j > 10:
break
else:
y = 10
return y
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
func_node = mod.body[0]
_, _, name_node_y = mod.nodes_of_class(astroid.Name)
self.checker.visit_functiondef(func_node)
with self.assertAddsMessages(
pylint.testutils.Message(
msg_id='possibly-undefined',
node=name_node_y,
), ):
self.checker.visit_name(name_node_y)
def main(filepath: str) -> None:
filename = os.path.splitext(os.path.basename(filepath))[0]
mod = AstroidBuilder().file_build(filepath)
visitor = CFGVisitor()
mod.accept(visitor)
display(visitor.cfgs, filename)
def build_cfgs(
src: str
) -> Dict[Union[nodes.FunctionDef, nodes.Module], ControlFlowGraph]:
mod = astroid.parse(src)
t = CFGVisitor()
mod.accept(t)
return t.cfgs
def build_cfg(src: str, is_function: Optional[bool] = False) -> ControlFlowGraph:
"""<is_function> == True guarantees that the function node is the first node
in the module."""
mod = astroid.parse(src)
t = CFGVisitor()
mod.accept(t)
if is_function:
return t.cfgs[mod.body[0]]
return t.cfgs[mod]
def test_no_message_loop(self):
src = """
y = 5
while y > 5:
x = 10
print(x)
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
_, assign_x, *_ = mod.nodes_of_class(astroid.Assign)
self.checker.visit_module(mod)
with self.assertNoMessages():
self.checker.visit_assign(assign_x)
def test_no_messages_simple(self):
src = """
x = 10
print(x)
x = 10
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
assign_1, *_ = mod.nodes_of_class(astroid.Assign)
with self.assertNoMessages():
self.checker.visit_module(mod)
self.checker.visit_assign(assign_1)
def test_no_message_loop_(self):
src = """
y = 0
for y in range(1, 10):
x = 10
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
_, assign_x, *_ = mod.nodes_of_class(astroid.Assign)
print(assign_x.as_string())
self.checker.visit_module(mod)
with self.assertNoMessages():
self.checker.visit_assign(assign_x)
def test_augassign_simple_no_message(self):
src = """
y_pos = 5
y_pos += 10
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
self.checker.visit_module(mod)
with self.assertNoMessages():
for node in mod.nodes_of_class(astroid.Assign):
self.checker.visit_assign(node)
for node in mod.nodes_of_class(astroid.AugAssign):
self.checker.visit_augassign(node)
def test_no_messages_with_args(self):
src = """
def test(x):
if True:
x = 10
print(x)
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
func_node = mod.body[0]
_, name_node_x = mod.nodes_of_class(astroid.Name)
with self.assertNoMessages():
self.checker.visit_functiondef(func_node)
self.checker.visit_name(name_node_x)
def test_with_comprehension(self):
src = """
def func(lst):
test = [x for x in lst]
x = 0
print(x)
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
func_node = mod.body[0]
# expression `x` at line `test = ...`
name_node_x = next(func_node.nodes_of_class(astroid.Name))
self.checker.visit_functiondef(func_node)
with self.assertNoMessages():
self.checker.visit_name(name_node_x)
def test_with_dict_comprehension(self):
src = """
def func(lst):
test = {key:val for key, val in lst}
key = 0
print(key)
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
func_node = mod.body[0]
# expression `key` at line `test = ...`
name_node_key = next(func_node.nodes_of_class(nodes.Name))
self.checker.visit_functiondef(func_node)
with self.assertNoMessages():
self.checker.visit_name(name_node_key)
def test_no_messages_if_else_with_ann_assign(self):
src = """
def test(x):
if True:
y: int = 10
else:
y = 20
print(y)
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
func_node = mod.body[0]
_, _, name_node_y = mod.nodes_of_class(astroid.Name)
with self.assertNoMessages():
self.checker.visit_functiondef(func_node)
self.checker.visit_name(name_node_y)
def test_no_messages_with_nonlocal(self):
src = """
def test(x):
x = 10
nonlocal y
if True:
y = 10
print(y)
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
func_node = mod.body[0]
__, name_node_y = mod.nodes_of_class(nodes.Name)
with self.assertNoMessages():
self.checker.visit_functiondef(func_node)
self.checker.visit_name(name_node_y)
def test_augassign_redundant(self):
src = """
y_pos = 5
y_pos += 10
y_pos = 10
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
augassign_node, *_ = mod.nodes_of_class(astroid.AugAssign)
self.checker.visit_module(mod)
with self.assertAddsMessages(
pylint.testutils.Message(
msg_id='redundant-assignment',
node=augassign_node,
)):
self.checker.visit_augassign(augassign_node)
def test_message_simple(self):
src = """
x = 10
x = 230
print(x)
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
assign_1, _ = mod.nodes_of_class(astroid.Assign)
self.checker.visit_module(mod)
with self.assertAddsMessages(
pylint.testutils.Message(
msg_id='redundant-assignment',
node=assign_1,
), ):
self.checker.visit_assign(assign_1)
def test_no_message_function_def(self):
src = """
x = 10
if False:
x = 20
else:
def func():
x = 1
print(x)
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
assign_x, *_ = mod.nodes_of_class(astroid.Assign)
self.checker.visit_module(mod)
with self.assertNoMessages():
self.checker.visit_assign(assign_x)
def test_no_message_loop_complex(self):
src = """
x = 10
for y in range(1, 10):
x = func(y)
print(x)
x = x - 1
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
assign_x1, assign_x2, assign_x3 = mod.nodes_of_class(astroid.Assign)
self.checker.visit_module(mod)
with self.assertNoMessages():
self.checker.visit_assign(assign_x1)
self.checker.visit_assign(assign_x2)
self.checker.visit_assign(assign_x3)
def test_no_messages_simple(self):
src = """
def test(x):
x = 10
if True:
return x
return x
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
func_node = mod.body[0]
name_node_a, name_node_b = mod.nodes_of_class(astroid.Name)
with self.assertNoMessages():
self.checker.visit_module(mod)
self.checker.visit_functiondef(func_node)
self.checker.visit_name(name_node_a)
self.checker.visit_name(name_node_b)
def test_message_with_func_name(self):
src = """
if True:
pass
else:
y = lambda: 20
y()
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
*_, name_node_y = mod.nodes_of_class(astroid.Name)
self.checker.visit_module(mod)
with self.assertAddsMessages(
pylint.testutils.Message(
msg_id='possibly-undefined',
node=name_node_y,
), ):
self.checker.visit_name(name_node_y)
def test_no_message_if_complex(self):
src = """
x = 10
y = 5
if y > 5:
x = 20
elif y > 50:
x = 15
else:
pass
print(x)
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
assign_x, *_ = mod.nodes_of_class(astroid.Assign)
self.checker.visit_module(mod)
with self.assertNoMessages():
self.checker.visit_assign(assign_x)
def test_message_with_args(self):
src = """
def test(x):
if True:
del x
print(x)
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
func_node = mod.body[0]
_, name_node_x = mod.nodes_of_class(astroid.Name)
self.checker.visit_functiondef(func_node)
with self.assertAddsMessages(
pylint.testutils.Message(
msg_id='possibly-undefined',
node=name_node_x,
), ):
self.checker.visit_name(name_node_x)
def test_message_with_del_simple(self):
src = """
def test(x):
y = 0
del y
print(y)
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
func_node = mod.body[0]
_, name_node_y = mod.nodes_of_class(nodes.Name)
self.checker.visit_functiondef(func_node)
with self.assertAddsMessages(
pylint.testutils.MessageTest(msg_id="possibly-undefined",
node=name_node_y),
ignore_position=True,
):
self.checker.visit_name(name_node_y)
def test_no_messages_with_class_def(self):
"""This example is a false negative due to how class definitions are
represented in the control flow graph."""
src = """
class A:
y = 10
if True:
x = 10
else:
y = 20
print(y)
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
_, name_node_y = mod.nodes_of_class(astroid.Name)
self.checker.visit_module(mod)
with self.assertNoMessages():
self.checker.visit_name(name_node_y)
def test_assign(self):
src = """
def func():
if False:
x = 10
x = x + 1
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
func_node = mod.body[0]
name_node_x = next(func_node.nodes_of_class(astroid.Name))
print(list(func_node.nodes_of_class(astroid.Name)))
self.checker.visit_functiondef(func_node)
with self.assertAddsMessages(
pylint.testutils.Message(
msg_id='possibly-undefined',
node=name_node_x,
)):
self.checker.visit_name(name_node_x)
def test_no_messages_with_import_from(self):
src = """
from random import j
y = 0
if y > 10:
j = 10
else:
y = 5
print(j)
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
name_node_y, name_node_print, name_node_j = mod.nodes_of_class(
astroid.Name)
with self.assertNoMessages():
self.checker.visit_module(mod)
self.checker.visit_name(name_node_y)
self.checker.visit_name(name_node_print)
self.checker.visit_name(name_node_j)
def test_message_scope(self):
src = """
x = 25
def func():
def func2():
print(x - 1)
func2()
x = 10
func()
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
assign_x, *_ = mod.nodes_of_class(astroid.Assign)
self.checker.visit_module(mod)
with self.assertAddsMessages(
pylint.testutils.Message(
msg_id='redundant-assignment',
node=assign_x,
)):
self.checker.visit_assign(assign_x)
def test_multiple_messages_simple(self):
src = """
if True:
y: int = 10
else:
x = 10
print(x and y)
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
_, _, name_node_x, name_node_y = mod.nodes_of_class(nodes.Name)
self.checker.visit_module(mod)
with self.assertAddsMessages(
pylint.testutils.MessageTest(msg_id="possibly-undefined",
node=name_node_y),
pylint.testutils.MessageTest(msg_id="possibly-undefined",
node=name_node_x),
ignore_position=True,
):
self.checker.visit_name(name_node_y)
self.checker.visit_name(name_node_x)
def test_message_if_stmt(self):
src = """
x = 10
y = 5
if y > 5:
x = 20
else:
x = 15
print(x)
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
assign_x, *_ = mod.nodes_of_class(astroid.Assign)
self.checker.visit_module(mod)
with self.assertAddsMessages(
pylint.testutils.Message(
msg_id='redundant-assignment',
node=assign_x,
), ):
self.checker.visit_assign(assign_x)
def test_no_messages_complex(self):
src = """
def test(x):
if True:
y = 10
else:
for j in range(10):
if j > 10:
y = 10
break
else:
y = 10
return y
"""
mod = astroid.parse(src)
mod.accept(CFGVisitor())
func_node = mod.body[0]
_, _, name_node_y = mod.nodes_of_class(astroid.Name)
with self.assertNoMessages():
self.checker.visit_functiondef(func_node)
self.checker.visit_name(name_node_y)
