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Edit File: plugin.py
# ext/mypy/plugin.py # Copyright (C) 2021 the SQLAlchemy authors and contributors # <see AUTHORS file> # # This module is part of SQLAlchemy and is released under # the MIT License: https://www.opensource.org/licenses/mit-license.php """ Mypy plugin for SQLAlchemy ORM. """ from typing import Callable from typing import List from typing import Optional from typing import Tuple from typing import Type as TypingType from typing import Union from mypy import nodes from mypy.mro import calculate_mro from mypy.mro import MroError from mypy.nodes import Block from mypy.nodes import ClassDef from mypy.nodes import GDEF from mypy.nodes import MypyFile from mypy.nodes import NameExpr from mypy.nodes import SymbolTable from mypy.nodes import SymbolTableNode from mypy.nodes import TypeInfo from mypy.plugin import AttributeContext from mypy.plugin import ClassDefContext from mypy.plugin import DynamicClassDefContext from mypy.plugin import Plugin from mypy.plugin import SemanticAnalyzerPluginInterface from mypy.types import get_proper_type from mypy.types import Instance from mypy.types import Type from . import decl_class from . import names from . import util class SQLAlchemyPlugin(Plugin): def get_dynamic_class_hook( self, fullname: str ) -> Optional[Callable[[DynamicClassDefContext], None]]: if names.type_id_for_fullname(fullname) is names.DECLARATIVE_BASE: return _dynamic_class_hook return None def get_customize_class_mro_hook( self, fullname: str ) -> Optional[Callable[[ClassDefContext], None]]: return _fill_in_decorators def get_class_decorator_hook( self, fullname: str ) -> Optional[Callable[[ClassDefContext], None]]: sym = self.lookup_fully_qualified(fullname) if sym is not None and sym.node is not None: type_id = names.type_id_for_named_node(sym.node) if type_id is names.MAPPED_DECORATOR: return _cls_decorator_hook elif type_id in ( names.AS_DECLARATIVE, names.AS_DECLARATIVE_BASE, ): return _base_cls_decorator_hook elif type_id is names.DECLARATIVE_MIXIN: return _declarative_mixin_hook return None def get_metaclass_hook( self, fullname: str ) -> Optional[Callable[[ClassDefContext], None]]: if names.type_id_for_fullname(fullname) is names.DECLARATIVE_META: # Set any classes that explicitly have metaclass=DeclarativeMeta # as declarative so the check in `get_base_class_hook()` works return _metaclass_cls_hook return None def get_base_class_hook( self, fullname: str ) -> Optional[Callable[[ClassDefContext], None]]: sym = self.lookup_fully_qualified(fullname) if ( sym and isinstance(sym.node, TypeInfo) and util.has_declarative_base(sym.node) ): return _base_cls_hook return None def get_attribute_hook( self, fullname: str ) -> Optional[Callable[[AttributeContext], Type]]: if fullname.startswith( "sqlalchemy.orm.attributes.QueryableAttribute." ): return _queryable_getattr_hook return None def get_additional_deps( self, file: MypyFile ) -> List[Tuple[int, str, int]]: return [ (10, "sqlalchemy.orm.attributes", -1), (10, "sqlalchemy.orm.decl_api", -1), ] def plugin(version: str) -> TypingType[SQLAlchemyPlugin]: return SQLAlchemyPlugin def _dynamic_class_hook(ctx: DynamicClassDefContext) -> None: """Generate a declarative Base class when the declarative_base() function is encountered.""" _add_globals(ctx) cls = ClassDef(ctx.name, Block([])) cls.fullname = ctx.api.qualified_name(ctx.name) info = TypeInfo(SymbolTable(), cls, ctx.api.cur_mod_id) cls.info = info _set_declarative_metaclass(ctx.api, cls) cls_arg = util.get_callexpr_kwarg(ctx.call, "cls", expr_types=(NameExpr,)) if cls_arg is not None and isinstance(cls_arg.node, TypeInfo): util.set_is_base(cls_arg.node) decl_class.scan_declarative_assignments_and_apply_types( cls_arg.node.defn, ctx.api, is_mixin_scan=True ) info.bases = [Instance(cls_arg.node, [])] else: obj = ctx.api.named_type(names.NAMED_TYPE_BUILTINS_OBJECT) info.bases = [obj] try: calculate_mro(info) except MroError: util.fail( ctx.api, "Not able to calculate MRO for declarative base", ctx.call ) obj = ctx.api.named_type(names.NAMED_TYPE_BUILTINS_OBJECT) info.bases = [obj] info.fallback_to_any = True ctx.api.add_symbol_table_node(ctx.name, SymbolTableNode(GDEF, info)) util.set_is_base(info) def _fill_in_decorators(ctx: ClassDefContext) -> None: for decorator in ctx.cls.decorators: # set the ".fullname" attribute of a class decorator # that is a MemberExpr. This causes the logic in # semanal.py->apply_class_plugin_hooks to invoke the # get_class_decorator_hook for our "registry.map_class()" # and "registry.as_declarative_base()" methods. # this seems like a bug in mypy that these decorators are otherwise # skipped. if ( isinstance(decorator, nodes.CallExpr) and isinstance(decorator.callee, nodes.MemberExpr) and decorator.callee.name == "as_declarative_base" ): target = decorator.callee elif ( isinstance(decorator, nodes.MemberExpr) and decorator.name == "mapped" ): target = decorator else: continue assert isinstance(target.expr, NameExpr) sym = ctx.api.lookup_qualified( target.expr.name, target, suppress_errors=True ) if sym and sym.node: sym_type = get_proper_type(sym.type) if isinstance(sym_type, Instance): target.fullname = f"{sym_type.type.fullname}.{target.name}" else: # if the registry is in the same file as where the # decorator is used, it might not have semantic # symbols applied and we can't get a fully qualified # name or an inferred type, so we are actually going to # flag an error in this case that they need to annotate # it. The "registry" is declared just # once (or few times), so they have to just not use # type inference for its assignment in this one case. util.fail( ctx.api, "Class decorator called %s(), but we can't " "tell if it's from an ORM registry. Please " "annotate the registry assignment, e.g. " "my_registry: registry = registry()" % target.name, sym.node, ) def _cls_decorator_hook(ctx: ClassDefContext) -> None: _add_globals(ctx) assert isinstance(ctx.reason, nodes.MemberExpr) expr = ctx.reason.expr assert isinstance(expr, nodes.RefExpr) and isinstance(expr.node, nodes.Var) node_type = get_proper_type(expr.node.type) assert ( isinstance(node_type, Instance) and names.type_id_for_named_node(node_type.type) is names.REGISTRY ) decl_class.scan_declarative_assignments_and_apply_types(ctx.cls, ctx.api) def _base_cls_decorator_hook(ctx: ClassDefContext) -> None: _add_globals(ctx) cls = ctx.cls _set_declarative_metaclass(ctx.api, cls) util.set_is_base(ctx.cls.info) decl_class.scan_declarative_assignments_and_apply_types( cls, ctx.api, is_mixin_scan=True ) def _declarative_mixin_hook(ctx: ClassDefContext) -> None: _add_globals(ctx) util.set_is_base(ctx.cls.info) decl_class.scan_declarative_assignments_and_apply_types( ctx.cls, ctx.api, is_mixin_scan=True ) def _metaclass_cls_hook(ctx: ClassDefContext) -> None: util.set_is_base(ctx.cls.info) def _base_cls_hook(ctx: ClassDefContext) -> None: _add_globals(ctx) decl_class.scan_declarative_assignments_and_apply_types(ctx.cls, ctx.api) def _queryable_getattr_hook(ctx: AttributeContext) -> Type: # how do I....tell it it has no attribute of a certain name? # can't find any Type that seems to match that return ctx.default_attr_type def _add_globals(ctx: Union[ClassDefContext, DynamicClassDefContext]) -> None: """Add __sa_DeclarativeMeta and __sa_Mapped symbol to the global space for all class defs """ util.add_global(ctx, "sqlalchemy.orm.attributes", "Mapped", "__sa_Mapped") def _set_declarative_metaclass( api: SemanticAnalyzerPluginInterface, target_cls: ClassDef ) -> None: info = target_cls.info sym = api.lookup_fully_qualified_or_none( "sqlalchemy.orm.decl_api.DeclarativeMeta" ) assert sym is not None and isinstance(sym.node, TypeInfo) info.declared_metaclass = info.metaclass_type = Instance(sym.node, [])