The builders annotated their ``children`` parameter as
``list[HTMLTag] | HTMLTag | None`` where ``HTMLTag = str``. ``list[str]`` is
invariant, so passing ``list[Element]`` / ``list[Node]`` — the normal case —
was a type error everywhere a component nested children.
Introduce a proper child type in core:
Child = Node | str
Children = Sequence[Child] | str | None
``Sequence`` is covariant, so ``list[Element]`` / ``list[Node]`` are accepted;
``Child`` includes ``Node`` so node children are no longer rejected. ``Element``
itself also accepts a bare ``Node`` (it wraps one), typed ``Children | Node``.
Replace the ``list[HTMLTag] | HTMLTag | None`` annotations across primitives /
domain with ``Children``, and add ``as_children()`` to normalise a ``children``
argument to a ``list[Child]`` — retiring the repeated
``children if isinstance(children, list) else [children]`` dance that defeated
type narrowing. Inline ``mark_safe(...)`` SVG/markup children become ``Safe(...)``
nodes (a ``Node`` child instead of a stub-typed string).
Pyright on the component package drops from 43 to 22 errors; the remaining 22
are pre-existing and unrelated (django-stubs model access, the ``mark_safe``
``_Wrapped`` return type, and ``list[HTMLAttribute]`` attribute invariance).
Full suite green (443).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
lukas
7104605c06
