Fix type checking for constructing tuples.

Author: dnwpark

gel/_internal/_codegen/_models/_pydantic.py

@@ -839,6 +839,14 @@ def _indirection_key(path: Indirection) -> tuple[str, ...]:
         SchemaPath("std", "multirange"),
     }
 )
+COLLECTION_TYPES = frozenset(
+    {
+        SchemaPath("std", "array"),
+        SchemaPath("std", "tuple"),
+        SchemaPath("std", "range"),
+        SchemaPath("std", "multirange"),
+    }
+)
 
 PSEUDO_TYPES = frozenset(("anytuple", "anyobject", "anytype"))
 
@@ -2517,7 +2525,17 @@ def write_generic_types(
                     suggested_module_alias=rel_import.module_alias,
                 )
                 type_ident = ident(gt.name)
-                self.write(f"{type_ident} = {imported_name}")
+
+                if gt in COLLECTION_TYPES:
+                    # Import collection classes directly so mypy sees them as
+                    # generic classes, not type aliases
+                    self.write(
+                        f"from {rel_import.module} "
+                        f"import {type_ident} as {type_ident}"
+                    )
+                else:
+                    self.write(f"{type_ident} = {imported_name}")
+
                 self.export(type_ident)
 
     def _write_enum_scalar_type(

gel/_internal/_qbmodel/_abstract/_primitive.py

@@ -358,7 +358,7 @@ def __edgeql_literal__(self) -> _qb.Literal:
         )
 
     @classmethod
-    def cast(cls, expr: _qb.ExprCompatible) -> type[Tuple[Unpack[_Ts]]]:
+    def cast(cls, expr: _qb.ExprCompatible) -> Self:
         return _qb.AnnotatedExpr(  # type: ignore [return-value]
             cls,
             _qb.CastOp(
@@ -367,6 +367,11 @@ def cast(cls, expr: _qb.ExprCompatible) -> type[Tuple[Unpack[_Ts]]]:
             ),
         )
 
+    if TYPE_CHECKING:
+
+        def __new__(cls, args: tuple[Any, ...]) -> Self: ...  # type: ignore[misc]
+        def __init__(self, args: tuple[Unpack[_Ts]]): ...  # type: ignore[misc]
+
 
 if TYPE_CHECKING:
 

tests/test_qb.py

@@ -1399,13 +1399,13 @@ def test_qb_cast_array_04(self):
                 std.array[std.tuple[std.str, std.str]](
                     [
                         std.tuple[std.str, std.str](
-                            [std.str("1"), std.str("Red")]
+                            (std.str("1"), std.str("Red"))
                         ),
                         std.tuple[std.str, std.str](
-                            [std.str("2"), std.str("Green")]
+                            (std.str("2"), std.str("Green"))
                         ),
                         std.tuple[std.str, std.str](
-                            [std.str("3"), std.str("Blue")]
+                            (std.str("3"), std.str("Blue"))
                         ),
                     ]
                 )