astroid/tests/unittest_inference_calls.py

590 lines
14 KiB
Python

"""Tests for function call inference"""
from astroid import bases, builder, nodes
from astroid.util import Uninferable
def test_no_return() -> None:
"""Test function with no return statements"""
node = builder.extract_node(
"""
def f():
pass
f() #@
"""
)
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert inferred[0] is Uninferable
def test_one_return() -> None:
"""Test function with a single return that always executes"""
node = builder.extract_node(
"""
def f():
return 1
f() #@
"""
)
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.Const)
assert inferred[0].value == 1
def test_one_return_possible() -> None:
"""Test function with a single return that only sometimes executes
Note: currently, inference doesn't handle this type of control flow
"""
node = builder.extract_node(
"""
def f(x):
if x:
return 1
f(1) #@
"""
)
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.Const)
assert inferred[0].value == 1
def test_multiple_returns() -> None:
"""Test function with multiple returns"""
node = builder.extract_node(
"""
def f(x):
if x > 10:
return 1
elif x > 20:
return 2
else:
return 3
f(100) #@
"""
)
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 3
assert all(isinstance(node, nodes.Const) for node in inferred)
assert {node.value for node in inferred} == {1, 2, 3}
def test_argument() -> None:
"""Test function whose return value uses its arguments"""
node = builder.extract_node(
"""
def f(x, y):
return x + y
f(1, 2) #@
"""
)
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.Const)
assert inferred[0].value == 3
def test_inner_call() -> None:
"""Test function where return value is the result of a separate function call"""
node = builder.extract_node(
"""
def f():
return g()
def g():
return 1
f() #@
"""
)
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.Const)
assert inferred[0].value == 1
def test_inner_call_with_const_argument() -> None:
"""Test function where return value is the result of a separate function call,
with a constant value passed to the inner function.
"""
node = builder.extract_node(
"""
def f():
return g(1)
def g(y):
return y + 2
f() #@
"""
)
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.Const)
assert inferred[0].value == 3
def test_inner_call_with_dynamic_argument() -> None:
"""Test function where return value is the result of a separate function call,
with a dynamic value passed to the inner function.
Currently, this is Uninferable.
"""
node = builder.extract_node(
"""
def f(x):
return g(x)
def g(y):
return y + 2
f(1) #@
"""
)
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert inferred[0] is Uninferable
def test_method_const_instance_attr() -> None:
"""Test method where the return value is based on an instance attribute with a
constant value.
"""
node = builder.extract_node(
"""
class A:
def __init__(self):
self.x = 1
def get_x(self):
return self.x
A().get_x() #@
"""
)
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.Const)
assert inferred[0].value == 1
def test_method_const_instance_attr_multiple() -> None:
"""Test method where the return value is based on an instance attribute with
multiple possible constant values, across different methods.
"""
node = builder.extract_node(
"""
class A:
def __init__(self, x):
if x:
self.x = 1
else:
self.x = 2
def set_x(self):
self.x = 3
def get_x(self):
return self.x
A().get_x() #@
"""
)
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 3
assert all(isinstance(node, nodes.Const) for node in inferred)
assert {node.value for node in inferred} == {1, 2, 3}
def test_method_const_instance_attr_same_method() -> None:
"""Test method where the return value is based on an instance attribute with
multiple possible constant values, including in the method being called.
Note that even with a simple control flow where the assignment in the method body
is guaranteed to override any previous assignments, all possible constant values
are returned.
"""
node = builder.extract_node(
"""
class A:
def __init__(self, x):
if x:
self.x = 1
else:
self.x = 2
def set_x(self):
self.x = 3
def get_x(self):
self.x = 4
return self.x
A().get_x() #@
"""
)
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 4
assert all(isinstance(node, nodes.Const) for node in inferred)
assert {node.value for node in inferred} == {1, 2, 3, 4}
def test_method_dynamic_instance_attr_1() -> None:
"""Test method where the return value is based on an instance attribute with
a dynamically-set value in a different method.
In this case, the return value is Uninferable.
"""
node = builder.extract_node(
"""
class A:
def __init__(self, x):
self.x = x
def get_x(self):
return self.x
A(1).get_x() #@
"""
)
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert inferred[0] is Uninferable
def test_method_dynamic_instance_attr_2() -> None:
"""Test method where the return value is based on an instance attribute with
a dynamically-set value in the same method.
"""
node = builder.extract_node(
"""
class A:
# Note: no initializer, so the only assignment happens in get_x
def get_x(self, x):
self.x = x
return self.x
A().get_x(1) #@
"""
)
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.Const)
assert inferred[0].value == 1
def test_method_dynamic_instance_attr_3() -> None:
"""Test method where the return value is based on an instance attribute with
a dynamically-set value in a different method.
This is currently Uninferable.
"""
node = builder.extract_node(
"""
class A:
def get_x(self, x): # x is unused
return self.x
def set_x(self, x):
self.x = x
A().get_x(10) #@
"""
)
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert inferred[0] is Uninferable # not 10!
def test_method_dynamic_instance_attr_4() -> None:
"""Test method where the return value is based on an instance attribute with
a dynamically-set value in a different method, and is passed a constant value.
This is currently Uninferable.
"""
node = builder.extract_node(
"""
class A:
# Note: no initializer, so the only assignment happens in get_x
def get_x(self):
self.set_x(10)
return self.x
def set_x(self, x):
self.x = x
A().get_x() #@
"""
)
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert inferred[0] is Uninferable
def test_method_dynamic_instance_attr_5() -> None:
"""Test method where the return value is based on an instance attribute with
a dynamically-set value in a different method, and is passed a constant value.
But, where the outer and inner functions have the same signature.
Inspired by https://github.com/PyCQA/pylint/issues/400
This is currently Uninferable.
"""
node = builder.extract_node(
"""
class A:
# Note: no initializer, so the only assignment happens in get_x
def get_x(self, x):
self.set_x(10)
return self.x
def set_x(self, x):
self.x = x
A().get_x(1) #@
"""
)
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert inferred[0] is Uninferable
def test_method_dynamic_instance_attr_6() -> None:
"""Test method where the return value is based on an instance attribute with
a dynamically-set value in a different method, and is passed a dynamic value.
This is currently Uninferable.
"""
node = builder.extract_node(
"""
class A:
# Note: no initializer, so the only assignment happens in get_x
def get_x(self, x):
self.set_x(x + 1)
return self.x
def set_x(self, x):
self.x = x
A().get_x(1) #@
"""
)
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert inferred[0] is Uninferable
def test_dunder_getitem() -> None:
"""Test for the special method __getitem__ (used by Instance.getitem).
This is currently Uninferable, until we can infer instance attribute values through
constructor calls.
"""
node = builder.extract_node(
"""
class A:
def __init__(self, x):
self.x = x
def __getitem__(self, i):
return self.x + i
A(1)[2] #@
"""
)
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert inferred[0] is Uninferable
def test_instance_method() -> None:
"""Tests for instance method, both bound and unbound."""
nodes_ = builder.extract_node(
"""
class A:
def method(self, x):
return x
A().method(42) #@
# In this case, the 1 argument is bound to self, which is ignored in the method
A.method(1, 42) #@
"""
)
for node in nodes_:
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.Const)
assert inferred[0].value == 42
def test_class_method() -> None:
"""Tests for class method calls, both instance and with the class."""
nodes_ = builder.extract_node(
"""
class A:
@classmethod
def method(cls, x):
return x
A.method(42) #@
A().method(42) #@
"""
)
for node in nodes_:
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.Const), node
assert inferred[0].value == 42
def test_static_method() -> None:
"""Tests for static method calls, both instance and with the class."""
nodes_ = builder.extract_node(
"""
class A:
@staticmethod
def method(x):
return x
A.method(42) #@
A().method(42) #@
"""
)
for node in nodes_:
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.Const), node
assert inferred[0].value == 42
def test_instance_method_inherited() -> None:
"""Tests for instance methods that are inherited from a superclass.
Based on https://github.com/PyCQA/astroid/issues/1008.
"""
nodes_ = builder.extract_node(
"""
class A:
def method(self):
return self
class B(A):
pass
A().method() #@
A.method(A()) #@
B().method() #@
B.method(B()) #@
A.method(B()) #@
"""
)
expected = ["A", "A", "B", "B", "B"]
for node, expected in zip(nodes_, expected):
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], bases.Instance)
assert inferred[0].name == expected
def test_class_method_inherited() -> None:
"""Tests for class methods that are inherited from a superclass.
Based on https://github.com/PyCQA/astroid/issues/1008.
"""
nodes_ = builder.extract_node(
"""
class A:
@classmethod
def method(cls):
return cls
class B(A):
pass
A().method() #@
A.method() #@
B().method() #@
B.method() #@
"""
)
expected = ["A", "A", "B", "B"]
for node, expected in zip(nodes_, expected):
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.ClassDef)
assert inferred[0].name == expected
def test_chained_attribute_inherited() -> None:
"""Tests for class methods that are inherited from a superclass.
Based on https://github.com/PyCQA/pylint/issues/4220.
"""
node = builder.extract_node(
"""
class A:
def f(self):
return 42
class B(A):
def __init__(self):
self.a = A()
result = self.a.f()
def f(self):
pass
B().a.f() #@
"""
)
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.Const)
assert inferred[0].value == 42