Files
django-stubs/mypy_django_plugin/transformers/querysets.py
2019-07-25 19:53:12 +03:00

192 lines
8.2 KiB
Python

from collections import OrderedDict
from typing import List, Optional, Sequence, Type, Union, cast
from django.core.exceptions import FieldError
from django.db.models.base import Model
from mypy.newsemanal.typeanal import TypeAnalyser
from mypy.nodes import Expression, NameExpr, TypeInfo
from mypy.plugin import AnalyzeTypeContext, FunctionContext, MethodContext
from mypy.types import AnyType, Instance
from mypy.types import Type as MypyType
from mypy.types import TypeOfAny
from mypy_django_plugin.django.context import DjangoContext
from mypy_django_plugin.lib import fullnames, helpers
def determine_proper_manager_type(ctx: FunctionContext) -> MypyType:
default_return_type = ctx.default_return_type
assert isinstance(default_return_type, Instance)
outer_model_info = helpers.get_typechecker_api(ctx).scope.active_class()
if (outer_model_info is None
or not outer_model_info.has_base(fullnames.MODEL_CLASS_FULLNAME)):
return default_return_type
return helpers.reparametrize_instance(default_return_type, [Instance(outer_model_info, [])])
def get_field_type_from_lookup(ctx: MethodContext, django_context: DjangoContext, model_cls: Type[Model],
*, method: str, lookup: str) -> Optional[MypyType]:
try:
lookup_field = django_context.lookups_context.resolve_lookup(model_cls, lookup)
except FieldError as exc:
ctx.api.fail(exc.args[0], ctx.context)
return None
field_get_type = django_context.fields_context.get_field_get_type(helpers.get_typechecker_api(ctx),
lookup_field, method=method)
return field_get_type
def get_values_list_row_type(ctx: MethodContext, django_context: DjangoContext, model_cls: Type[Model],
flat: bool, named: bool) -> MypyType:
field_lookups = resolve_field_lookups(ctx.args[0], ctx, django_context)
if field_lookups is None:
return AnyType(TypeOfAny.from_error)
typechecker_api = helpers.get_typechecker_api(ctx)
if len(field_lookups) == 0:
if flat:
primary_key_field = django_context.get_primary_key_field(model_cls)
lookup_type = get_field_type_from_lookup(ctx, django_context, model_cls,
lookup=primary_key_field.attname, method='values_list')
assert lookup_type is not None
return lookup_type
elif named:
column_types: 'OrderedDict[str, MypyType]' = OrderedDict()
for field in django_context.get_model_fields(model_cls):
column_type = django_context.fields_context.get_field_get_type(typechecker_api, field,
method='values_list')
column_types[field.attname] = column_type
return helpers.make_oneoff_named_tuple(typechecker_api, 'Row', column_types)
else:
# flat=False, named=False, all fields
field_lookups = []
for field in django_context.get_model_fields(model_cls):
field_lookups.append(field.attname)
if len(field_lookups) > 1 and flat:
typechecker_api.fail("'flat' is not valid when 'values_list' is called with more than one field", ctx.context)
return AnyType(TypeOfAny.from_error)
column_types = OrderedDict()
for field_lookup in field_lookups:
lookup_field_type = get_field_type_from_lookup(ctx, django_context, model_cls,
lookup=field_lookup, method='values_list')
if lookup_field_type is None:
return AnyType(TypeOfAny.from_error)
column_types[field_lookup] = lookup_field_type
if flat:
assert len(column_types) == 1
row_type = next(iter(column_types.values()))
elif named:
row_type = helpers.make_oneoff_named_tuple(typechecker_api, 'Row', column_types)
else:
row_type = helpers.make_tuple(typechecker_api, list(column_types.values()))
return row_type
def extract_proper_type_queryset_values_list(ctx: MethodContext, django_context: DjangoContext) -> MypyType:
# called on the Instance, returns QuerySet of something
assert isinstance(ctx.type, Instance)
assert isinstance(ctx.default_return_type, Instance)
# bail if queryset of Any or other non-instances
if not isinstance(ctx.type.args[0], Instance):
return AnyType(TypeOfAny.from_omitted_generics)
model_type = ctx.type.args[0]
model_cls = django_context.get_model_class_by_fullname(model_type.type.fullname())
if model_cls is None:
return ctx.default_return_type
flat_expr = helpers.get_call_argument_by_name(ctx, 'flat')
if flat_expr is not None and isinstance(flat_expr, NameExpr):
flat = helpers.parse_bool(flat_expr)
else:
flat = False
named_expr = helpers.get_call_argument_by_name(ctx, 'named')
if named_expr is not None and isinstance(named_expr, NameExpr):
named = helpers.parse_bool(named_expr)
else:
named = False
if flat and named:
ctx.api.fail("'flat' and 'named' can't be used together", ctx.context)
return helpers.reparametrize_instance(ctx.default_return_type, [model_type, AnyType(TypeOfAny.from_error)])
# account for possible None
flat = flat or False
named = named or False
row_type = get_values_list_row_type(ctx, django_context, model_cls,
flat=flat, named=named)
return helpers.reparametrize_instance(ctx.default_return_type, [model_type, row_type])
def resolve_field_lookups(lookup_exprs: Sequence[Expression], ctx: Union[FunctionContext, MethodContext],
django_context: DjangoContext) -> Optional[List[str]]:
field_lookups = []
for field_lookup_expr in lookup_exprs:
field_lookup = helpers.resolve_string_attribute_value(field_lookup_expr, ctx, django_context)
if field_lookup is None:
return None
field_lookups.append(field_lookup)
return field_lookups
def extract_proper_type_queryset_values(ctx: MethodContext, django_context: DjangoContext) -> MypyType:
# called on QuerySet, return QuerySet of something
assert isinstance(ctx.type, Instance)
assert isinstance(ctx.default_return_type, Instance)
# if queryset of non-instance type
if not isinstance(ctx.type.args[0], Instance):
return AnyType(TypeOfAny.from_omitted_generics)
model_type = ctx.type.args[0]
model_cls = django_context.get_model_class_by_fullname(model_type.type.fullname())
if model_cls is None:
return ctx.default_return_type
field_lookups = resolve_field_lookups(ctx.args[0], ctx, django_context)
if field_lookups is None:
return AnyType(TypeOfAny.from_error)
if len(field_lookups) == 0:
for field in django_context.get_model_fields(model_cls):
field_lookups.append(field.attname)
column_types: 'OrderedDict[str, MypyType]' = OrderedDict()
for field_lookup in field_lookups:
field_lookup_type = get_field_type_from_lookup(ctx, django_context, model_cls,
lookup=field_lookup, method='values')
if field_lookup_type is None:
return helpers.reparametrize_instance(ctx.default_return_type, [model_type, AnyType(TypeOfAny.from_error)])
column_types[field_lookup] = field_lookup_type
row_type = helpers.make_typeddict(ctx.api, column_types, set(column_types.keys()))
return helpers.reparametrize_instance(ctx.default_return_type, [model_type, row_type])
def set_first_generic_param_as_default_for_second(ctx: AnalyzeTypeContext, fullname: str) -> MypyType:
type_analyser_api = cast(TypeAnalyser, ctx.api)
info = helpers.lookup_fully_qualified_typeinfo(type_analyser_api.api, fullname) # type: ignore
assert isinstance(info, TypeInfo)
if not ctx.type.args:
return Instance(info, [AnyType(TypeOfAny.explicit), AnyType(TypeOfAny.explicit)])
args = ctx.type.args
if len(args) == 1:
args = [args[0], args[0]]
analyzed_args = [type_analyser_api.analyze_type(arg) for arg in args]
return Instance(info, analyzed_args)