[ty] Support dataclasses.InitVar

Author: InSyncWithFoo

crates/ty_python_semantic/src/module_resolver/module.rs

@@ -344,6 +344,10 @@ impl KnownModule {
     pub const fn is_importlib(self) -> bool {
         matches!(self, Self::ImportLib)
     }
+
+    pub const fn is_dataclasses(self) -> bool {
+        matches!(self, Self::Dataclasses)
+    }
 }
 
 impl std::fmt::Display for KnownModule {

crates/ty_python_semantic/src/types.rs

@@ -5214,7 +5214,7 @@ impl<'db> Type<'db> {
                     })
                 }
 
-                SpecialFormType::ClassVar | SpecialFormType::Final => {
+                SpecialFormType::ClassVar | SpecialFormType::Final | SpecialFormType::InitVar => {
                     Err(InvalidTypeExpressionError {
                         invalid_expressions: smallvec::smallvec_inline![
                             InvalidTypeExpression::TypeQualifier(*special_form)
@@ -6137,6 +6137,8 @@ bitflags! {
         const CLASS_VAR = 1 << 0;
         /// `typing.Final`
         const FINAL     = 1 << 1;
+        /// `dataclasses.InitVar`
+        const INIT_VAR  = 1 << 2;
     }
 }
 

crates/ty_python_semantic/src/types/class_base.rs

@@ -192,7 +192,8 @@ impl<'db> ClassBase<'db> {
                 | SpecialFormType::TypeOf
                 | SpecialFormType::CallableTypeOf
                 | SpecialFormType::AlwaysTruthy
-                | SpecialFormType::AlwaysFalsy => None,
+                | SpecialFormType::AlwaysFalsy
+                | SpecialFormType::InitVar => None,
 
                 SpecialFormType::Unknown => Some(Self::unknown()),
 

crates/ty_python_semantic/src/types/infer.rs

@@ -9064,6 +9064,9 @@ impl<'db> TypeInferenceBuilder<'db, '_> {
                         Type::SpecialForm(SpecialFormType::Final) => {
                             TypeAndQualifiers::new(Type::unknown(), TypeQualifiers::FINAL)
                         }
+                        Type::SpecialForm(SpecialFormType::InitVar) => {
+                            TypeAndQualifiers::new(Type::unknown(), TypeQualifiers::INIT_VAR)
+                        }
                         _ => name_expr_ty
                             .in_type_expression(self.db(), self.scope())
                             .unwrap_or_else(|error| {
@@ -9123,7 +9126,9 @@ impl<'db> TypeInferenceBuilder<'db, '_> {
                         }
                     }
                     Type::SpecialForm(
-                        type_qualifier @ (SpecialFormType::ClassVar | SpecialFormType::Final),
+                        type_qualifier @ (SpecialFormType::ClassVar
+                        | SpecialFormType::Final
+                        | SpecialFormType::InitVar),
                     ) => {
                         let arguments = if let ast::Expr::Tuple(tuple) = slice {
                             &*tuple.elts
@@ -9141,6 +9146,9 @@ impl<'db> TypeInferenceBuilder<'db, '_> {
                                 SpecialFormType::Final => {
                                     type_and_qualifiers.add_qualifier(TypeQualifiers::FINAL);
                                 }
+                                SpecialFormType::InitVar => {
+                                    type_and_qualifiers.add_qualifier(TypeQualifiers::INIT_VAR);
+                                }
                                 _ => unreachable!(),
                             }
                             type_and_qualifiers
@@ -10332,7 +10340,7 @@ impl<'db> TypeInferenceBuilder<'db, '_> {
                 self.infer_type_expression(arguments_slice);
                 todo_type!("`NotRequired[]` type qualifier")
             }
-            SpecialFormType::ClassVar | SpecialFormType::Final => {
+            SpecialFormType::ClassVar | SpecialFormType::Final | SpecialFormType::InitVar => {
                 if let Some(builder) = self.context.report_lint(&INVALID_TYPE_FORM, subscript) {
                     let diag = builder.into_diagnostic(format_args!(
                         "Type qualifier `{special_form}` is not allowed in type expressions \

crates/ty_python_semantic/src/types/special_form.rs

@@ -105,6 +105,8 @@ pub enum SpecialFormType {
     TypeIs,
     /// The symbol `typing.ReadOnly` (which can also be found as `typing_extensions.ReadOnly`)
     ReadOnly,
+    /// The symbol `dataclasses.InitVar`
+    InitVar,
 
     /// The symbol `typing.Protocol` (which can also be found as `typing_extensions.Protocol`)
     ///
@@ -150,7 +152,8 @@ impl SpecialFormType {
             | Self::CallableTypeOf
             | Self::Protocol  // actually `_ProtocolMeta` at runtime but this is what typeshed says
             | Self::Generic  // actually `type` at runtime but this is what typeshed says
-            | Self::ReadOnly => KnownClass::SpecialForm,
+            | Self::ReadOnly
+            | Self::InitVar => KnownClass::SpecialForm,
 
             Self::List
             | Self::Dict
@@ -241,6 +244,8 @@ impl SpecialFormType {
             | Self::Intersection
             | Self::TypeOf
             | Self::CallableTypeOf => module.is_ty_extensions(),
+
+            Self::InitVar => module.is_dataclasses(),
         }
     }
 
@@ -297,7 +302,8 @@ impl SpecialFormType {
             | Self::TypeIs
             | Self::ReadOnly
             | Self::Protocol
-            | Self::Generic => false,
+            | Self::Generic
+            | Self::InitVar => false,
         }
     }
 
@@ -344,6 +350,7 @@ impl SpecialFormType {
             SpecialFormType::CallableTypeOf => "ty_extensions.CallableTypeOf",
             SpecialFormType::Protocol => "typing.Protocol",
             SpecialFormType::Generic => "typing.Generic",
+            SpecialFormType::InitVar => "dataclasses.InitVar",
         }
     }
 }