tokencrawler/.venv/lib/python3.9/site-packages/apischema/validation/dependencies.py
2022-03-17 22:16:30 +01:00

63 lines
2 KiB
Python

import ast
import inspect
import textwrap
from typing import AbstractSet, Callable, Collection, Dict, Set
Dependencies = AbstractSet[str]
class DependencyFinder(ast.NodeVisitor):
def __init__(self, param: str):
self.param = param
self.dependencies: Set[str] = set()
def visit_Attribute(self, node):
self.generic_visit(node)
if isinstance(node.value, ast.Name) and node.value.id == self.param:
self.dependencies.add(node.attr)
# TODO Add warning in case of function call with self in parameter
# or better, follow the call, but it would be too hard (local import, etc.)
def first_parameter(func: Callable) -> str:
try:
return next(iter(inspect.signature(func).parameters))
except StopIteration:
raise TypeError("Cannot compute dependencies if no parameter")
def find_dependencies(func: Callable) -> Dependencies:
try:
finder = DependencyFinder(first_parameter(func))
finder.visit(ast.parse(textwrap.dedent(inspect.getsource(func))))
except ValueError:
return set()
return finder.dependencies
cache: Dict[Callable, Dependencies] = {}
def find_all_dependencies(
cls: type, func: Callable, rec_guard: Collection[str] = ()
) -> Dependencies:
"""Dependencies contains class variables (because they can be "fake" ones as in
dataclasses)"""
if func not in cache:
dependencies = set(find_dependencies(func))
for attr in list(dependencies):
if not hasattr(cls, attr):
continue
member = getattr(cls, attr)
if isinstance(member, property):
member = member.fget
if callable(member):
dependencies.remove(attr)
if member in rec_guard:
continue
rec_deps = find_all_dependencies(cls, member, {*rec_guard, member})
dependencies.update(rec_deps)
cache[func] = dependencies
return cache[func]