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# Copyright (c) 2015-2018, 2020 Claudiu Popa <pcmanticore@gmail.com>
# Copyright (c) 2015-2016 Ceridwen <ceridwenv@gmail.com>
# Copyright (c) 2016 Jakub Wilk <jwilk@jwilk.net>
# Copyright (c) 2018 Bryce Guinta <bryce.paul.guinta@gmail.com>
# Copyright (c) 2019 Ashley Whetter <ashley@awhetter.co.uk>
# Copyright (c) 2020 hippo91 <guillaume.peillex@gmail.com>
# Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html
# For details: https://github.com/PyCQA/astroid/blob/master/COPYING.LESSER
from __future__ import print_function
import contextlib
import time
import unittest
from astroid import builder
from astroid import nodes
from astroid import parse
from astroid import transforms
@contextlib.contextmanager
def add_transform(manager, node, transform, predicate=None):
manager.register_transform(node, transform, predicate)
try:
yield
finally:
manager.unregister_transform(node, transform, predicate)
class TestTransforms(unittest.TestCase):
def setUp(self):
self.transformer = transforms.TransformVisitor()
def parse_transform(self, code):
module = parse(code, apply_transforms=False)
return self.transformer.visit(module)
def test_function_inlining_transform(self):
def transform_call(node):
# Let's do some function inlining
inferred = next(node.infer())
return inferred
self.transformer.register_transform(nodes.Call, transform_call)
module = self.parse_transform(
"""
def test(): return 42
test() #@
"""
)
self.assertIsInstance(module.body[1], nodes.Expr)
self.assertIsInstance(module.body[1].value, nodes.Const)
self.assertEqual(module.body[1].value.value, 42)
def test_recursive_transforms_into_astroid_fields(self):
# Test that the transformer walks properly the tree
# by going recursively into the _astroid_fields per each node.
def transform_compare(node):
# Let's check the values of the ops
_, right = node.ops[0]
# Assume they are Consts and they were transformed before
# us.
return nodes.const_factory(node.left.value < right.value)
def transform_name(node):
# Should be Consts
return next(node.infer())
self.transformer.register_transform(nodes.Compare, transform_compare)
self.transformer.register_transform(nodes.Name, transform_name)
module = self.parse_transform(
"""
a = 42
b = 24
a < b
"""
)
self.assertIsInstance(module.body[2], nodes.Expr)
self.assertIsInstance(module.body[2].value, nodes.Const)
self.assertFalse(module.body[2].value.value)
def test_transform_patches_locals(self):
def transform_function(node):
assign = nodes.Assign()
name = nodes.AssignName()
name.name = "value"
assign.targets = [name]
assign.value = nodes.const_factory(42)
node.body.append(assign)
self.transformer.register_transform(nodes.FunctionDef, transform_function)
module = self.parse_transform(
"""
def test():
pass
"""
)
func = module.body[0]
self.assertEqual(len(func.body), 2)
self.assertIsInstance(func.body[1], nodes.Assign)
self.assertEqual(func.body[1].as_string(), "value = 42")
def test_predicates(self):
def transform_call(node):
inferred = next(node.infer())
return inferred
def should_inline(node):
return node.func.name.startswith("inlineme")
self.transformer.register_transform(nodes.Call, transform_call, should_inline)
module = self.parse_transform(
"""
def inlineme_1():
return 24
def dont_inline_me():
return 42
def inlineme_2():
return 2
inlineme_1()
dont_inline_me()
inlineme_2()
"""
)
values = module.body[-3:]
self.assertIsInstance(values[0], nodes.Expr)
self.assertIsInstance(values[0].value, nodes.Const)
self.assertEqual(values[0].value.value, 24)
self.assertIsInstance(values[1], nodes.Expr)
self.assertIsInstance(values[1].value, nodes.Call)
self.assertIsInstance(values[2], nodes.Expr)
self.assertIsInstance(values[2].value, nodes.Const)
self.assertEqual(values[2].value.value, 2)
def test_transforms_are_separated(self):
# Test that the transforming is done at a separate
# step, which means that we are not doing inference
# on a partially constructed tree anymore, which was the
# source of crashes in the past when certain inference rules
# were used in a transform.
def transform_function(node):
if node.decorators:
for decorator in node.decorators.nodes:
inferred = next(decorator.infer())
if inferred.qname() == "abc.abstractmethod":
return next(node.infer_call_result())
return None
manager = builder.MANAGER
with add_transform(manager, nodes.FunctionDef, transform_function):
module = builder.parse(
"""
import abc
from abc import abstractmethod
class A(object):
@abc.abstractmethod
def ala(self):
return 24
@abstractmethod
def bala(self):
return 42
"""
)
cls = module["A"]
ala = cls.body[0]
bala = cls.body[1]
self.assertIsInstance(ala, nodes.Const)
self.assertEqual(ala.value, 24)
self.assertIsInstance(bala, nodes.Const)
self.assertEqual(bala.value, 42)
def test_transforms_are_called_for_builtin_modules(self):
# Test that transforms are called for builtin modules.
def transform_function(node):
name = nodes.AssignName()
name.name = "value"
node.args.args = [name]
return node
manager = builder.MANAGER
predicate = lambda node: node.root().name == "time"
with add_transform(manager, nodes.FunctionDef, transform_function, predicate):
builder_instance = builder.AstroidBuilder()
module = builder_instance.module_build(time)
asctime = module["asctime"]
self.assertEqual(len(asctime.args.args), 1)
self.assertIsInstance(asctime.args.args[0], nodes.AssignName)
self.assertEqual(asctime.args.args[0].name, "value")
def test_builder_apply_transforms(self):
def transform_function(node):
return nodes.const_factory(42)
manager = builder.MANAGER
with add_transform(manager, nodes.FunctionDef, transform_function):
astroid_builder = builder.AstroidBuilder(apply_transforms=False)
module = astroid_builder.string_build("""def test(): pass""")
# The transform wasn't applied.
self.assertIsInstance(module.body[0], nodes.FunctionDef)
def test_transform_crashes_on_is_subtype_of(self):
# Test that we don't crash when having is_subtype_of
# in a transform, as per issue #188. This happened
# before, when the transforms weren't in their own step.
def transform_class(cls):
if cls.is_subtype_of("django.db.models.base.Model"):
return cls
return cls
self.transformer.register_transform(nodes.ClassDef, transform_class)
self.parse_transform(
"""
# Change environ to automatically call putenv() if it exists
import os
putenv = os.putenv
try:
# This will fail if there's no putenv
putenv
except NameError:
pass
else:
import UserDict
"""
)
if __name__ == "__main__":
unittest.main()
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