Components consuming load functions no longer need non-null assertions

Currently, load functions are clumsy to use from TypeScript because the RouteSectionProps type marks the data prop as optional. If you try working around that in your component (such as Component<Required<RouteSectionProps<MyProps>>>), you instead get compile errors that your component's props type isn't assignable to RouteDefinition.

The only workaround I've found is runtime null checks or type-level non-null assertions, at every call site that touches the data prop inside a component.

This PR marks the data prop as non-optional: the route props will always have a data field, set to the RouteSectionProps generic parameter type. If not load function is supplied, the field's value would be undefined, with a type of unknown.

What happens if the route doesn't have a load function defined? Your component would be declared as Component<RouteSectionProps>. Without the type param supplied, the data prop receives type unknown, and is unusable inside your component.

If a component sometimes does/doesn't receive load data, it can use Component<RouteSectionProps<Foo | undefined>>.

This approach provides accurate types when you have a load function, and still signals the data prop cannot be read when you do not have a load function.

solidjs / solid-router

Components consuming load functions no longer need non-null assertions #419

⚠️ No Changeset found