def _get_field_default(field_call: Call) -> Tuple[str, Optional[NodeNG]]:
"""Return a the default value of a field call, and the corresponding keyword argument name.
field(default=...) results in the ... node
field(default_factory=...) results in a Call node with func ... and no arguments
If neither or both arguments are present, return ("", None) instead,
indicating that there is not a valid default value.
"""
default, default_factory = None, None
for keyword in field_call.keywords:
if keyword.arg == "default":
default = keyword.value
elif keyword.arg == "default_factory":
default_factory = keyword.value
if default is not None and default_factory is None:
return "default", default
if default is None and default_factory is not None:
new_call = Call(
lineno=field_call.lineno,
col_offset=field_call.col_offset,
parent=field_call.parent,
)
new_call.postinit(func=default_factory)
return "default_factory", new_call
return "", None
def _looks_like_dataclass_field_call(node: Call,
check_scope: bool = True) -> bool:
"""Return True if node is calling dataclasses field or Field
from an AnnAssign statement directly in the body of a ClassDef.
If check_scope is False, skips checking the statement and body.
"""
if check_scope:
stmt = node.statement(future=True)
scope = stmt.scope()
if not (isinstance(stmt, AnnAssign) and stmt.value is not None
and isinstance(scope, ClassDef)
and is_decorated_with_dataclass(scope)):
return False
try:
inferred = next(node.func.infer())
except (InferenceError, StopIteration):
return False
if not isinstance(inferred, FunctionDef):
return False
return inferred.name == FIELD_NAME and inferred.root(
).name in DATACLASS_MODULES
def transform_call(node: Call) -> Const:
# Let's do some function inlining
inferred = next(node.infer())
return inferred
def transform_call(node: Call) -> Const:
inferred = next(node.infer())
return inferred