LibCST/libcst/codemod/tests/test_codemod.py
2023-03-15 11:53:50 +00:00

99 lines
2.5 KiB
Python

# Copyright (c) Meta Platforms, Inc. and affiliates.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.
#
from unittest import expectedFailure
import libcst as cst
import libcst.matchers as m
from libcst.codemod import Codemod, CodemodContext, CodemodTest, SkipFile
class SimpleCodemod(Codemod):
def __init__(self, context: CodemodContext, *, skip: bool) -> None:
super().__init__(context)
self.skip = skip
def transform_module_impl(self, tree: cst.Module) -> cst.Module:
if self.skip:
raise SkipFile()
else:
return tree
class TestSkipDetection(CodemodTest):
TRANSFORM = SimpleCodemod
def test_detect_skip(self) -> None:
code = """
def foo() -> None:
pass
def bar() -> int:
return 5
"""
self.assertCodemod(code, code, skip=False, expected_skip=False)
self.assertCodemod(code, code, skip=True, expected_skip=True)
@expectedFailure
def test_did_not_skip_but_should(self) -> None:
code = """
def foo() -> None:
pass
def bar() -> int:
return 5
"""
self.assertCodemod(code, code, skip=False, expected_skip=True)
@expectedFailure
def test_skipped_but_should_not(self) -> None:
code = """
def foo() -> None:
pass
def bar() -> int:
return 5
"""
self.assertCodemod(code, code, skip=True, expected_skip=False)
class IncrementCodemod(Codemod):
def __init__(self, context: CodemodContext, *, iterations: int) -> None:
super().__init__(context)
self.iterations = iterations
def should_allow_multiple_passes(self) -> bool:
return True
def transform_module_impl(self, tree: cst.Module) -> cst.Module:
if self.iterations == 0:
return tree
self.iterations -= 1
return cst.ensure_type(
m.replace(
tree,
m.Integer(),
lambda node, _: node.with_changes(value=str(int(node.value) + 1)),
),
cst.Module,
)
class TestMultipass(CodemodTest):
TRANSFORM = IncrementCodemod
def test_multi_iterations(self) -> None:
before = """
x = 5
"""
after = """
x = 10
"""
self.assertCodemod(before, after, iterations=5)