new semanal wip 1

mypy_django_plugin_newsemanal/lib/helpers.py

@@ -0,0 +1,99 @@
+from typing import Dict, List, Optional, Set, Union
+
+from mypy.nodes import Expression, MypyFile, NameExpr, SymbolNode, TypeInfo, Var
+from mypy.plugin import FunctionContext, MethodContext
+from mypy.types import AnyType, Instance, NoneTyp, Type as MypyType, TypeOfAny, UnionType
+
+
+class IncompleteDefnException(Exception):
+    pass
+
+
+def lookup_fully_qualified_generic(name: str, all_modules: Dict[str, MypyFile]) -> Optional[SymbolNode]:
+    if '.' not in name:
+        return None
+    module, cls_name = name.rsplit('.', 1)
+
+    module_file = all_modules.get(module)
+    if module_file is None:
+        return None
+    sym = module_file.names.get(cls_name)
+    if sym is None:
+        return None
+    return sym.node
+
+
+def reparametrize_instance(instance: Instance, new_args: List[MypyType]) -> Instance:
+    return Instance(instance.type, args=new_args,
+                    line=instance.line, column=instance.column)
+
+
+def get_class_fullname(klass: type) -> str:
+    return klass.__module__ + '.' + klass.__qualname__
+
+
+def get_call_argument_by_name(ctx: Union[FunctionContext, MethodContext], name: str) -> Optional[Expression]:
+    """
+    Return the expression for the specific argument.
+    This helper should only be used with non-star arguments.
+    """
+    if name not in ctx.callee_arg_names:
+        return None
+    idx = ctx.callee_arg_names.index(name)
+    args = ctx.args[idx]
+    if len(args) != 1:
+        # Either an error or no value passed.
+        return None
+    return args[0]
+
+
+def get_call_argument_type_by_name(ctx: Union[FunctionContext, MethodContext], name: str) -> Optional[MypyType]:
+    """Return the type for the specific argument.
+
+    This helper should only be used with non-star arguments.
+    """
+    if name not in ctx.callee_arg_names:
+        return None
+    idx = ctx.callee_arg_names.index(name)
+    arg_types = ctx.arg_types[idx]
+    if len(arg_types) != 1:
+        # Either an error or no value passed.
+        return None
+    return arg_types[0]
+
+
+def make_optional(typ: MypyType) -> MypyType:
+    return UnionType.make_union([typ, NoneTyp()])
+
+
+def parse_bool(expr: Expression) -> Optional[bool]:
+    if isinstance(expr, NameExpr):
+        if expr.fullname == 'builtins.True':
+            return True
+        if expr.fullname == 'builtins.False':
+            return False
+    return None
+
+
+def has_any_of_bases(info: TypeInfo, bases: Set[str]) -> bool:
+    for base_fullname in bases:
+        if info.has_base(base_fullname):
+            return True
+    return False
+
+
+def get_private_descriptor_type(type_info: TypeInfo, private_field_name: str, is_nullable: bool) -> MypyType:
+    node = type_info.get(private_field_name).node
+    if isinstance(node, Var):
+        descriptor_type = node.type
+        if is_nullable:
+            descriptor_type = make_optional(descriptor_type)
+        return descriptor_type
+    return AnyType(TypeOfAny.unannotated)
+
+
+def get_nested_meta_node_for_current_class(info: TypeInfo) -> Optional[TypeInfo]:
+    metaclass_sym = info.names.get('Meta')
+    if metaclass_sym is not None and isinstance(metaclass_sym.node, TypeInfo):
+        return metaclass_sym.node
+    return None