def leave_ImportFrom(self, original_node: cst.ImportFrom,
updated_node: cst.ImportFrom) -> cst.ImportFrom:
module = updated_node.module
if module is None:
return updated_node
imported_module_name = get_full_name_for_node(module)
names = original_node.names
if imported_module_name is None or not isinstance(names, Sequence):
return updated_node
else:
new_names = []
for import_alias in names:
alias_name = get_full_name_for_node(import_alias.name)
if alias_name is not None:
qual_name = f"{imported_module_name}.{alias_name}"
if self.old_name == qual_name:
replacement_module = self.gen_replacement_module(
imported_module_name)
replacement_obj = self.gen_replacement(alias_name)
if not replacement_obj:
# The user has requested an `import` statement rather than an `from ... import`.
# This will be taken care of in `leave_Module`, in the meantime, schedule for potential removal.
new_names.append(import_alias)
self.scheduled_removals.add(original_node)
continue
new_import_alias_name: Union[
cst.Attribute,
cst.Name] = self.gen_name_or_attr_node(
replacement_obj)
# Rename on the spot only if this is the only imported name under the module.
if len(names) == 1:
self.bypass_import = True
return updated_node.with_changes(
module=cst.parse_expression(
replacement_module),
names=(cst.ImportAlias(
name=new_import_alias_name), ),
)
# Or if the module name is to stay the same.
elif replacement_module == imported_module_name:
self.bypass_import = True
new_names.append(
cst.ImportAlias(name=new_import_alias_name))
else:
if self.old_name.startswith(qual_name + "."):
# This import might be in use elsewhere in the code, so schedule a potential removal.
self.scheduled_removals.add(original_node)
new_names.append(import_alias)
return updated_node.with_changes(names=new_names)
return updated_node
def leave_ImportFrom(self, original_node: libcst.ImportFrom,
updated_node: libcst.ImportFrom) -> libcst.ImportFrom:
if isinstance(updated_node.names, libcst.ImportStar):
# There's nothing to do here!
return updated_node
# Get the module we're importing as a string, see if we have work to do.
module = get_absolute_module_for_import(self.context.full_module_name,
updated_node)
if (module is None or module not in self.module_mapping
and module not in self.alias_mapping):
return updated_node
# We have work to do, mark that we won't modify this again.
imports_to_add = self.module_mapping.get(module, [])
if module in self.module_mapping:
del self.module_mapping[module]
aliases_to_add = self.alias_mapping.get(module, [])
if module in self.alias_mapping:
del self.alias_mapping[module]
# Now, do the actual update.
return updated_node.with_changes(names=[
*(libcst.ImportAlias(name=libcst.Name(imp))
for imp in sorted(imports_to_add)),
*(libcst.ImportAlias(
name=libcst.Name(imp),
asname=libcst.AsName(name=libcst.Name(alias)),
) for (imp, alias) in sorted(aliases_to_add)),
*updated_node.names,
])
def leave_ImportFrom(
self, original_node: cst.ImportFrom, updated_node: cst.ImportFrom
) -> Union[cst.RemovalSentinel, cst.ImportFrom]:
if isinstance(updated_node.names, cst.ImportStar):
def get_star_imp() -> Optional[ImportFrom]:
if isinstance(updated_node.module, cst.Attribute):
import_name = self.get_import_name_from_attr(
attr_node=updated_node.module)
else:
import_name = updated_node.module.value
location = self.get_location(original_node)
for imp in self.unused_imports:
if (isinstance(imp, ImportFrom) and imp.name == import_name
and imp.lineno == location.start.line):
return imp
else:
return None
imp = get_star_imp()
if imp:
return self.leave_StarImport(updated_node, imp)
else:
return original_node
rpar = self.get_rpar(updated_node.rpar,
self.get_location(original_node))
return self.leave_import_alike(original_node,
updated_node.with_changes(rpar=rpar))
def leave_ImportFrom(
self, original_node: cst.ImportFrom, updated_node: cst.ImportFrom
) -> Union[cst.ImportFrom, cst.RemovalSentinel]:
# Grab the scope for this import. If we don't have scope, we can't determine
# whether this import is unused so it is unsafe to remove.
scope = self.get_metadata(ScopeProvider, original_node, None)
if scope is None:
return updated_node
# Make sure we have anything to do with this node.
names = original_node.names
if isinstance(names, cst.ImportStar):
# This is a star import, so we won't remove it.
return updated_node
# Make sure we actually know the absolute module.
module_name = get_absolute_module_for_import(
self.context.full_module_name, updated_node
)
if module_name is None or module_name not in self.unused_obj_imports:
# This node isn't on our list of todos, so let's bail.
return updated_node
objects_to_remove = self.unused_obj_imports[module_name]
names_to_keep = []
for import_alias in names:
# Figure out if it is in our list of things to kill
for name, alias in objects_to_remove:
if (
name == import_alias.evaluated_name
and alias == import_alias.evaluated_alias
):
break
else:
# This is a keeper, we don't have it on our list.
names_to_keep.append(import_alias)
continue
# Now that we know we want to remove this object, figure out if
# there are any live references to it.
if self._is_in_use(scope, import_alias):
names_to_keep.append(import_alias)
continue
# no changes
if names_to_keep == names:
return updated_node
# Now, either remove this statement or remove the imports we are
# deleting from this statement.
if len(names_to_keep) == 0:
return cst.RemoveFromParent()
if names_to_keep[-1] != names[-1]:
# Remove trailing comma in order to not mess up import statements.
names_to_keep = [
*names_to_keep[:-1],
names_to_keep[-1].with_changes(comma=cst.MaybeSentinel.DEFAULT),
]
return updated_node.with_changes(names=names_to_keep)
def leave_StarImport(
updated_node: cst.ImportFrom,
imp: ImportFrom,
) -> Union[cst.ImportFrom, cst.RemovalSentinel]:
if imp.suggestions:
names_to_suggestions = [
cst.ImportAlias(cst.Name(module)) for module in imp.suggestions
]
return updated_node.with_changes(names=names_to_suggestions)
else:
return cst.RemoveFromParent()
def leave_ImportFrom(self, original_node: cst.ImportFrom,
updated_node: cst.ImportFrom) -> cst.ImportFrom:
self.import_statements.append(original_node)
# pyre-fixme[6]: Expected `Union[Attribute, Name]` for 1st param but got
# `Optional[Union[Attribute, Name]]`.
key = _get_attribute_as_string(original_node.module)
if (original_node.module is not None
# pyre-fixme[16]: `Optional` has no attribute `value`.
and original_node.module.value in self.imports):
names = list(updated_node.names) + self.imports[key].names
updated_node = updated_node.with_changes(names=tuple(names))
del self.imports[key]
return updated_node
def leave_StarImport(original_node: cst.ImportFrom,
updated_node: cst.ImportFrom,
**kwargs) -> Union[cst.ImportFrom, RemovalSentinel]:
imp = kwargs["imp"]
if imp["modules"]:
modules = ",".join(imp["modules"])
names_to_suggestion = []
for module in modules.split(","):
names_to_suggestion.append(cst.ImportAlias(cst.Name(module)))
return updated_node.with_changes(names=names_to_suggestion)
else:
if imp["module"]:
return cst.RemoveFromParent()
return original_node
def _check_import_from_parent(
self, original_node: ImportFrom, updated_node: ImportFrom
) -> Optional[Union[BaseSmallStatement, RemovalSentinel]]:
"""
Check for when the parent module of thing to replace is imported.
When `parent.module.the_thing` is transformed, detect such import:
from parent import module
"""
# First, exit early if 'import *' is used
if isinstance(updated_node.names, ImportStar):
return None
# Check whether parent module is imported
if not import_from_matches(updated_node, self.old_parent_module_parts):
return None
# Match, update the node an return it
new_import_aliases = []
for import_alias in updated_node.names:
if import_alias.evaluated_name == self.old_parent_name:
self.save_import_scope(original_node)
module_name_str = (import_alias.evaluated_alias
or import_alias.evaluated_name)
self.context.scratch[self.ctx_key_name_matcher] = m.Attribute(
value=m.Name(module_name_str),
attr=m.Name(self.old_name),
)
self.context.scratch[self.ctx_key_new_func] = Attribute(
attr=Name(self.new_name),
value=Name(import_alias.evaluated_alias
or self.new_parent_name),
)
if self.old_parent_module_parts != self.new_parent_module_parts:
# import statement needs updating
AddImportsVisitor.add_needed_import(
context=self.context,
module=".".join(self.new_parent_module_parts),
obj=self.new_parent_name,
asname=import_alias.evaluated_alias,
)
continue
new_import_aliases.append(import_alias)
if not new_import_aliases:
# Nothing left in the import statement: remove it
return RemoveFromParent()
# Some imports are left, update the statement
new_import_aliases = clean_new_import_aliases(new_import_aliases)
return updated_node.with_changes(names=new_import_aliases)
def leave_ImportFrom(
self, original_node: ImportFrom, updated_node: ImportFrom
) -> Union[BaseSmallStatement, RemovalSentinel]:
"""Update import statements for matching old module name."""
if not import_from_matches(updated_node,
self.old_module_parts) or isinstance(
updated_node.names, ImportStar):
return updated_node
# This is a match
new_names = list(self.gen_new_imported_names(updated_node.names))
self.save_import_scope(original_node)
if not new_names:
# Nothing left in the import statement: remove it
return RemoveFromParent()
# Some imports are left, update the statement
cleaned_names = self.tidy_new_imported_names(new_names)
return updated_node.with_changes(names=cleaned_names)
def leave_ImportFrom(
self, original_node: ImportFrom, updated_node: ImportFrom
) -> Union[BaseSmallStatement, RemovalSentinel]:
if isinstance(updated_node.names, ImportStar):
return super().leave_ImportFrom(original_node, updated_node)
if m.matches(
updated_node,
m.ImportFrom(module=module_matcher(["django", "db"])),
):
for imported_name in updated_node.names:
if m.matches(imported_name, m.ImportAlias(name=m.Name("models"))):
self.add_decorator_matcher(
m.Decorator(
decorator=m.Attribute(
value=m.Name("models"), attr=m.Name("permalink")
)
)
)
if m.matches(
updated_node,
m.ImportFrom(module=module_matcher(["django", "db", "models"])),
):
updated_names = []
for imported_name in updated_node.names:
if m.matches(imported_name, m.ImportAlias(name=m.Name("permalink"))):
decorator_name_str = (
imported_name.evaluated_alias or imported_name.evaluated_name
)
self.add_decorator_matcher(
m.Decorator(decorator=m.Name(decorator_name_str))
)
else:
updated_names.append(imported_name)
if not updated_names:
return RemoveFromParent()
# sort imports
new_names = sorted(updated_names, key=lambda n: n.evaluated_name)
# remove any trailing commas
last_name = new_names[-1]
if last_name.comma != MaybeSentinel.DEFAULT:
new_names[-1] = last_name.with_changes(comma=MaybeSentinel.DEFAULT)
return updated_node.with_changes(names=new_names)
return super().leave_ImportFrom(original_node, updated_node)
def leave_ImportFrom(self, original_node: cst.ImportFrom,
updated_node: cst.ImportFrom):
new_names = []
if m.matches(updated_node.names, m.ImportStar()):
new_names = updated_node.names
else:
for el in updated_node.names:
el_name = el.name.value
if self.can_rename(
el_name) and self.name_generator.in_dictionary(
el_name):
el = el.with_changes(name=self.get_new_cst_name(el_name))
new_names.append(el)
updated_node = updated_node.with_changes(names=new_names)
return updated_node
def leave_ImportFrom(
self, original_node: cst.ImportFrom, updated_node: cst.ImportFrom
) -> cst.ImportFrom:
self.import_statements.append(original_node)
# pyre-fixme[6]: Expected `Union[Attribute, Name]` for 1st param but got
# `Optional[Union[Attribute, Name]]`.
key = _get_attribute_as_string(original_node.module)
import_names = updated_node.names
module = original_node.module
if (
module is not None
and module.value in self.imports
and not isinstance(import_names, cst.ImportStar)
):
names_as_string = [_get_name_as_string(name.name) for name in import_names]
updated_names = self.imports[key].names.union(set(names_as_string))
names = [cst.ImportAlias(cst.Name(name)) for name in sorted(updated_names)]
updated_node = updated_node.with_changes(names=tuple(names))
del self.imports[key]
return updated_node
def leave_ImportFrom(self, original_node: cst.ImportFrom,
updated_node: cst.ImportFrom) -> cst.ImportFrom:
code = self.get_metadata(cst.metadata.PositionProvider, original_node)
line_no = code.start.line
new_import_alias = []
if isinstance(updated_node.names, cst.ImportStar):
# we do not handle ImportStar
return updated_node
for import_alias in updated_node.names:
if self.is_reimport_from(line_no, updated_node.module,
import_alias):
continue
new_import_alias.append(import_alias)
if new_import_alias:
new_import_alias[-1] = new_import_alias[-1].with_changes(
comma=cst.MaybeSentinel.DEFAULT)
return updated_node.with_changes(names=new_import_alias)
if len(new_import_alias) == 0:
return cst.RemoveFromParent()
return updated_node
def leave_ImportFrom(
self, original_node: cst.ImportFrom, updated_node: cst.ImportFrom
) -> Union[cst.ImportFrom, cst.RemovalSentinel]:
names = original_node.names
if isinstance(names, cst.ImportStar):
# This is a star import, so we won't remove it.
return updated_node
# Make sure we actually know the absolute module.
module_name = get_absolute_module_for_import(
self.context.full_module_name, updated_node)
if module_name is None or module_name not in self.unused_obj_imports:
# This node isn't on our list of todos, so let's bail.
return updated_node
updates = self._process_importfrom_aliases(updated_node, names,
module_name)
names_to_keep = updates["names"]
# no changes
if names_to_keep == names:
return updated_node
# Now, either remove this statement or remove the imports we are
# deleting from this statement.
if len(names_to_keep) == 0:
return cst.RemoveFromParent()
if names_to_keep[-1] != names[-1]:
# Remove trailing comma in order to not mess up import statements.
names_to_keep = [
*names_to_keep[:-1],
names_to_keep[-1].with_changes(
comma=cst.MaybeSentinel.DEFAULT),
]
updates["names"] = names_to_keep
return updated_node.with_changes(**updates)
def leave_ImportFrom(self, original_node: libcst.ImportFrom,
updated_node: libcst.ImportFrom) -> libcst.ImportFrom:
if len(updated_node.relative) > 0 or updated_node.module is None:
# Don't support relative-only imports at the moment.
return updated_node
if updated_node.names == "*":
# There's nothing to do here!
return updated_node
# Get the module we're importing as a string, see if we have work to do
module = self._get_string_name(updated_node.module)
if module not in self.module_mapping and module not in self.alias_mapping:
return updated_node
# We have work to do, mark that we won't modify this again.
imports_to_add = self.module_mapping.get(module, [])
if module in self.module_mapping:
del self.module_mapping[module]
aliases_to_add = self.alias_mapping.get(module, [])
if module in self.alias_mapping:
del self.alias_mapping[module]
# Now, do the actual update.
return updated_node.with_changes(names=(
*[
libcst.ImportAlias(name=libcst.Name(imp))
for imp in imports_to_add
],
*[
libcst.ImportAlias(
name=libcst.Name(imp),
asname=libcst.AsName(name=libcst.Name(alias)),
) for (imp, alias) in aliases_to_add
],
*updated_node.names,
))
