def _get_async_expr_replacement(
self, node: cst.CSTNode) -> Optional[cst.CSTNode]:
if m.matches(node, m.Call()):
node = cast(cst.Call, node)
return self._get_async_call_replacement(node)
elif m.matches(node, m.Attribute()):
node = cast(cst.Attribute, node)
return self._get_async_attr_replacement(node)
elif m.matches(node, m.UnaryOperation(operator=m.Not())):
node = cast(cst.UnaryOperation, node)
replacement_expression = self._get_async_expr_replacement(
node.expression)
if replacement_expression is not None:
return node.with_changes(expression=replacement_expression)
elif m.matches(node, m.BooleanOperation()):
node = cast(cst.BooleanOperation, node)
maybe_left = self._get_async_expr_replacement(node.left)
maybe_right = self._get_async_expr_replacement(node.right)
if maybe_left is not None or maybe_right is not None:
left_replacement = maybe_left if maybe_left is not None else node.left
right_replacement = (maybe_right if maybe_right is not None
else node.right)
return node.with_changes(left=left_replacement,
right=right_replacement)
return None
def __assert_codegen(
self,
node: cst.CSTNode,
expected: str,
expected_position: Optional[CodeRange] = None,
) -> None:
"""
Verifies that the given node's `_codegen` method is correct.
"""
module = cst.Module([])
self.assertEqual(module.code_for_node(node), expected)
if expected_position is not None:
# This is using some internal APIs, because we only want to compute
# position for the node being tested, not a whole module.
#
# Normally, this is a nonsense operation (how can a node have a position if
# its not in a module?), which is why it's not supported, but it makes
# sense in the context of these node tests.
provider = PositionProvider()
state = PositionProvidingCodegenState(
default_indent=module.default_indent,
default_newline=module.default_newline,
provider=provider,
)
node._codegen(state)
self.assertEqual(provider._computed[node], expected_position)
def _replace_or_remove(
parent: cst.CSTNode,
original_node: cst.CSTNode,
replacement_node: Union[cst.CSTNode, cst.RemovalSentinel],
) -> cst.CSTNode:
if isinstance(replacement_node, cst.RemovalSentinel):
return cst.ensure_type(parent.deep_remove(original_node), cst.CSTNode)
else:
return parent.deep_replace(original_node, replacement_node)
def basic_parenthesize(
node: libcst.CSTNode,
whitespace: Optional[libcst.BaseParenthesizableWhitespace] = None,
) -> libcst.CSTNode:
if not hasattr(node, "lpar"):
return node
if whitespace:
return node.with_changes(
lpar=[libcst.LeftParen(whitespace_after=whitespace)],
rpar=[libcst.RightParen()],
)
return node.with_changes(lpar=[libcst.LeftParen()], rpar=[libcst.RightParen()])
def remove_unused_import_by_node(context: CodemodContext,
node: cst.CSTNode) -> None:
"""
Schedule any imports referenced by ``node`` or one of its children
to be removed in a future invocation of this class by updating the
``context`` to include the ``module``, ``obj`` and ``alias`` for each
import in question. When subclassing from
:class:`~libcst.codemod.CodemodCommand`, this will be performed for you
after your transform finishes executing. If you are subclassing from a
:class:`~libcst.codemod.Codemod` instead, you will need to call the
:meth:`~libcst.codemod.Codemod.transform_module` method on the module
under modification with an instance of this class after performing your
transform. Note that all imports that are referenced by this ``node``
or its children will only be removed if they are not in use at the time
of exeucting :meth:`~libcst.codemod.Codemod.transform_module`
on an instance of :class:`~libcst.codemod.visitors.AddImportsVisitor`
in order to avoid removing an in-use import.
"""
# Special case both Import and ImportFrom so they can be
# directly removed here.
if isinstance(node, cst.Import):
for import_alias in node.names:
RemoveImportsVisitor.remove_unused_import(
context,
import_alias.evaluated_name,
asname=import_alias.evaluated_alias,
)
elif isinstance(node, cst.ImportFrom):
names = node.names
if isinstance(names, cst.ImportStar):
# We don't handle removing this, so ignore it.
return
module_name = get_absolute_module_for_import(
context.full_module_name, node)
if module_name is None:
raise Exception(
"Cannot look up absolute module from relative import!")
for import_alias in names:
RemoveImportsVisitor.remove_unused_import(
context,
module_name,
obj=import_alias.evaluated_name,
asname=import_alias.evaluated_alias,
)
else:
# Look up all children that could have been imported. Any that
# we find will be scheduled for removal.
node.visit(RemovedNodeVisitor(context))
def rewrite(self, tree: cst.CSTNode, env: SymbolTable,
metadata: tp.MutableMapping) -> PASS_ARGS_T:
if self.replace_and:
visitor = AndTransformer()
tree = tree.visit(visitor)
if self.replace_or:
visitor = OrTransformer()
tree = tree.visit(visitor)
if self.replace_not:
visitor = NotTransformer()
tree = tree.visit(visitor)
return tree, env, metadata
def assert_node_equal(self, first: libcst.CSTNode,
second: libcst.CSTNode) -> None:
"""Check that two libcst nodes are equal."""
if not first.deep_equals(second):
self.fail(
f"Nodes are not equal\nGot: {utils.to_string(first)}\nExpected: {utils.to_string(second)}"
)
def _maybe_autofix_node(self, node: cst.CSTNode,
attribute_name: str) -> None:
replacement_value = self._get_async_expr_replacement(
getattr(node, attribute_name))
if replacement_value is not None:
replacement = node.with_changes(
**{attribute_name: replacement_value})
self.report(node, replacement=replacement)
def _cst_node_equality_func(
a: cst.CSTNode, b: cst.CSTNode, msg: Optional[str] = None
) -> None:
"""
For use with addTypeEqualityFunc.
"""
if not a.deep_equals(b):
suffix = "" if msg is None else f"\n{msg}"
raise AssertionError(f"\n{a!r}\nis not deeply equal to \n{b!r}{suffix}")
def __assert_visit_returns_identity(self, node: cst.CSTNode) -> None:
"""
When visit is called with a visitor that acts as a no-op, the visit method
should return the same node it started with.
"""
# TODO: We're only checking equality right now, because visit currently clones
# the node, since that was easier to implement. We should fix that behavior in a
# later version and tighten this check.
self.assertEqual(node, node.visit(_NOOPVisitor()))
def _replace_names(
node: libcst.CSTNode,
wrapper: libcst.metadata.MetadataWrapper,
replacements: Dict[str, libcst.CSTNode],
) -> libcst.CSTNode:
replacer = _ReplaceTransformer(replacements)
with replacer.resolve(wrapper):
# The result of node.visit can never be a RemovalSentinel.
return cast(libcst.CSTNode, node.visit(replacer))
def _leave(self, original: cst.CSTNode, updated: cst.CSTNode) -> cst.CSTNode:
# TODO: if global scope query create a module tree from scratch?
# NOTE: in the future can cache lib cst node comparisons for speed
match = notFound
if first_ref_index is not None:
match = tryFind(lambda m: original.deep_equals(
m.path[first_ref_index].node), matches)
if match is not notFound:
from_assert = first(astNodeFromAssertion(transform, match))
return from_assert
elif original in transform.references:
# TODO: replace references to anything destroyed by the transform
pass
elif find_attempt is notFound and isinstance(updated, cst.Module):
module_match = Match(
[CaptureExpr().contextualize(node=updated)])
return updated.with_changes(body=(*updated.body, *astNodeFromAssertion(transform, module_match)))
else:
return updated
def _add_one_to_arg(
node: cst.CSTNode,
extraction: Dict[str, Union[cst.CSTNode, Sequence[cst.CSTNode]]],
) -> cst.CSTNode:
return node.deep_replace(
# This can be either a node or a sequence, pyre doesn't know.
cst.ensure_type(extraction["arg"], cst.CSTNode),
# Grab the arg and add one to its value.
cst.Integer(
str(
int(cst.ensure_type(extraction["arg"], cst.Integer).value)
+ 1)),
)
def rewrite(self,
tree: cst.CSTNode,
env: SymbolTable,
metadata: tp.MutableMapping) -> PASS_ARGS_T:
if not isinstance(self.phi, str):
phi_name = gen_free_name(tree, env, self.phi_name_prefix)
env.locals[phi_name] = self.phi
else:
phi_name = self.phi
visitor = IfExpTransformer(phi_name)
tree = tree.visit(visitor)
return tree, env, metadata
def assert_(py_ast: cst.CSTNode, transform: Transform) -> cst.CSTNode:
"""
TODO: in programming `assert` has a context of being passive, not fixing if it finds that it's incorrect,
perhaps a more active word should be chosen. Maybe *ensure*?
"""
matches = transform.matches
first_ref_index = None
find_attempt = tryFirst(transform.capture_reference_indices)
if find_attempt is not notFound:
_, (first_ref_index, _) = first(transform.capture_reference_indices)
@ unified_visit
class Transformer(cst.CSTTransformer):
def _leave(self, original: cst.CSTNode, updated: cst.CSTNode) -> cst.CSTNode:
# TODO: if global scope query create a module tree from scratch?
# NOTE: in the future can cache lib cst node comparisons for speed
match = notFound
if first_ref_index is not None:
match = tryFind(lambda m: original.deep_equals(
m.path[first_ref_index].node), matches)
if match is not notFound:
from_assert = first(astNodeFromAssertion(transform, match))
return from_assert
elif original in transform.references:
# TODO: replace references to anything destroyed by the transform
pass
elif find_attempt is notFound and isinstance(updated, cst.Module):
module_match = Match(
[CaptureExpr().contextualize(node=updated)])
return updated.with_changes(body=(*updated.body, *astNodeFromAssertion(transform, module_match)))
else:
return updated
transformed_tree = py_ast.visit(Transformer())
return transformed_tree
def render_node(node: cst.CSTNode, module: Optional[cst.Module] = None) -> str:
if module is None:
module = cst.Module(body=[])
code = module.code_for_node(node.with_changes(leading_lines=()))
return code
def rewrite(self, tree: cst.CSTNode, env: SymbolTable,
metadata: tp.MutableMapping) -> PASS_ARGS_T:
visitor = AssertRemover()
tree = tree.visit(visitor)
return tree, env, metadata
def _handle_suppression_comment(
self,
parent_node: cst.CSTNode,
parent_attribute_name: str,
index: int,
local_supp_comment: SuppressionComment,
comment_physical_line: int,
) -> None:
ignored_rules = local_supp_comment.ignored_rules
# Just a check for the type-checker - it should never actually be AllRulesType
# because we don't support that in lint-fixme/lint-ignore comments.
# TODO: We can remove the AllRulesType check once we deprecate noqa.
if isinstance(ignored_rules, AllRulesType):
return
# First find the suppressed rules that were included in the lint run. If a rule was not included
# in this run, we CANNOT know for sure that this lint suppression is unused.
ignored_rules_that_ran = {ig for ig in ignored_rules if ig in self.rule_names}
if not ignored_rules_that_ran:
return
lines_span = len(local_supp_comment.tokens)
unneeded_codes = _get_unused_codes_in_comment(
local_supp_comment, ignored_rules_that_ran
)
if unneeded_codes:
new_comment_lines = _compose_new_comment(
local_supp_comment, unneeded_codes, comment_physical_line
)
if not new_comment_lines:
# If we're here, all of the codes in this suppression refer to rules that ran, and
# none of comment's codes suppress anything, so we report this comment and offer to remove it.
new_parent_attribute_value = _modify_parent_attribute(
parent_node, parent_attribute_name, index, index + lines_span, []
)
self.report(
parent_node,
message=UNUSED_SUPPRESSION_COMMENT_MESSAGE,
replacement=parent_node.with_changes(
**{parent_attribute_name: new_parent_attribute_value}
),
)
else:
node_to_replace = getattr(parent_node, parent_attribute_name)[index]
replacement_emptyline_nodes = [
cst.EmptyLine(
indent=node_to_replace.indent,
whitespace=node_to_replace.whitespace,
comment=cst.Comment(line),
)
for line in new_comment_lines
]
new_parent_attribute_value: List[
cst.EmptyLine
] = _modify_parent_attribute(
parent_node,
parent_attribute_name,
index,
index + lines_span,
replacement_emptyline_nodes,
)
self.report(
parent_node,
message=UNUSED_SUPPRESSION_CODES_IN_COMMENT_MESSAGE.format(
lint_codes="`, `".join(uc for uc in unneeded_codes)
),
replacement=parent_node.with_changes(
**{parent_attribute_name: new_parent_attribute_value}
),
)
def unmangle_nodes(
tree: cst.CSTNode,
template_replacements: Mapping[str, ValidReplacementType],
) -> cst.CSTNode:
unmangler = TemplateTransformer(template_replacements)
return ensure_type(tree.visit(unmangler), cst.CSTNode)
def unroll_for_loops(tree: cst.CSTNode,
env: tp.Mapping[str, tp.Any]) -> cst.CSTNode:
return tree.visit(Unroller(env))
def _normalize(node: cst.CSTNode):
node = node.visit(StripParens())
node = node.visit(WhiteSpaceNormalizer())
node.validate_types_deep()
return node
def test_deep_equals_fails(self, a: cst.CSTNode, b: cst.CSTNode) -> None:
self.assertFalse(a.deep_equals(b))
def test_deep_equals_success(self, a: cst.CSTNode, b: cst.CSTNode) -> None:
self.assertTrue(a.deep_equals(b))
def renamed(self, old_node: cst.CSTNode):
return old_node.with_changes(name=self.get_new_cst_name(old_node.name))
def obf_universal(self, node: cst.CSTNode, *types):
if m.matches(node, m.Name()):
types = ('a', 'ca', 'v', 'cv') if not types else types
node = cst.ensure_type(node, cst.Name)
if self.can_rename(node.value, *types):
node = self.get_new_cst_name(node)
elif m.matches(node, m.NameItem()):
node = cst.ensure_type(node, cst.NameItem)
node = node.with_changes(name=self.obf_universal(node.name))
elif m.matches(node, m.Call()):
node = cst.ensure_type(node, cst.Call)
if self.change_methods or self.change_functions:
node = self.new_obf_function_name(node)
if self.change_arguments or self.change_method_arguments:
node = self.obf_function_args(node)
elif m.matches(node, m.Attribute()):
node = cst.ensure_type(node, cst.Attribute)
value = node.value
attr = node.attr
self.obf_universal(value)
self.obf_universal(attr)
elif m.matches(node, m.AssignTarget()):
node = cst.ensure_type(node, cst.AssignTarget)
node = node.with_changes(target=self.obf_universal(node.target))
elif m.matches(node, m.List() | m.Tuple()):
node = cst.ensure_type(node, cst.List) if m.matches(
node, m.List()) else cst.ensure_type(node, cst.Tuple)
new_elements = []
for el in node.elements:
new_elements.append(self.obf_universal(el))
node = node.with_changes(elements=new_elements)
elif m.matches(node, m.Subscript()):
node = cst.ensure_type(node, cst.Subscript)
new_slice = []
for el in node.slice:
new_slice.append(
el.with_changes(slice=self.obf_slice(el.slice)))
node = node.with_changes(slice=new_slice)
node = node.with_changes(value=self.obf_universal(node.value))
elif m.matches(node, m.Element()):
node = cst.ensure_type(node, cst.Element)
node = node.with_changes(value=self.obf_universal(node.value))
elif m.matches(node, m.Dict()):
node = cst.ensure_type(node, cst.Dict)
new_elements = []
for el in node.elements:
new_elements.append(self.obf_universal(el))
node = node.with_changes(elements=new_elements)
elif m.matches(node, m.DictElement()):
node = cst.ensure_type(node, cst.DictElement)
new_key = self.obf_universal(node.key)
new_val = self.obf_universal(node.value)
node = node.with_changes(key=new_key, value=new_val)
elif m.matches(node, m.StarredDictElement()):
node = cst.ensure_type(node, cst.StarredDictElement)
node = node.with_changes(value=self.obf_universal(node.value))
elif m.matches(node, m.If() | m.While()):
node = cst.ensure_type(node, cst.IfExp) if m.matches(
node, cst.If
| cst.IfExp) else cst.ensure_type(node, cst.While)
node = node.with_changes(test=self.obf_universal(node.test))
elif m.matches(node, m.IfExp()):
node = cst.ensure_type(node, cst.IfExp)
node = node.with_changes(body=self.obf_universal(node.body))
node = node.with_changes(test=self.obf_universal(node.test))
node = node.with_changes(orelse=self.obf_universal(node.orelse))
elif m.matches(node, m.Comparison()):
node = cst.ensure_type(node, cst.Comparison)
new_compars = []
for target in node.comparisons:
new_compars.append(self.obf_universal(target))
node = node.with_changes(left=self.obf_universal(node.left))
node = node.with_changes(comparisons=new_compars)
elif m.matches(node, m.ComparisonTarget()):
node = cst.ensure_type(node, cst.ComparisonTarget)
node = node.with_changes(
comparator=self.obf_universal(node.comparator))
elif m.matches(node, m.FormattedString()):
node = cst.ensure_type(node, cst.FormattedString)
new_parts = []
for part in node.parts:
new_parts.append(self.obf_universal(part))
node = node.with_changes(parts=new_parts)
elif m.matches(node, m.FormattedStringExpression()):
node = cst.ensure_type(node, cst.FormattedStringExpression)
node = node.with_changes(
expression=self.obf_universal(node.expression))
elif m.matches(node, m.BinaryOperation() | m.BooleanOperation()):
node = cst.ensure_type(node, cst.BinaryOperation) if m.matches(
node, m.BinaryOperation()) else cst.ensure_type(
node, cst.BooleanOperation)
node = node.with_changes(left=self.obf_universal(node.left),
right=self.obf_universal(node.right))
elif m.matches(node, m.UnaryOperation()):
node = cst.ensure_type(node, cst.UnaryOperation)
node = node.with_changes(
expression=self.obf_universal(node.expression))
elif m.matches(node, m.ListComp()):
node = cst.ensure_type(node, cst.ListComp)
node = node.with_changes(elt=self.obf_universal(node.elt))
node = node.with_changes(for_in=self.obf_universal(node.for_in))
elif m.matches(node, m.DictComp()):
node = cst.ensure_type(node, cst.DictComp)
node = node.with_changes(key=self.obf_universal(node.key))
node = node.with_changes(value=self.obf_universal(node.value))
node = node.with_changes(for_in=self.obf_universal(node.for_in))
elif m.matches(node, m.CompFor()):
node = cst.ensure_type(node, cst.CompFor)
new_ifs = []
node = node.with_changes(target=self.obf_universal(node.target))
node = node.with_changes(iter=self.obf_universal(node.iter))
for el in node.ifs:
new_ifs.append(self.obf_universal(el))
node = node.with_changes(ifs=new_ifs)
elif m.matches(node, m.CompIf()):
node = cst.ensure_type(node, cst.CompIf)
node = node.with_changes(test=self.obf_universal(node.test))
elif m.matches(node, m.Integer() | m.Float() | m.SimpleString()):
pass
else:
pass
# print(node)
return node
