Function: typedSpec()

API / @xmachines/play-view / index / typedSpec

function typedSpec(spec): ViewMeta;

Defined in: packages/play-view/src/view-types.ts:126

The identity helper gives a view spec literal the type ViewMeta at the definition site. The compiler therefore checks the spec, and the IDE completes it.

The XState meta field has the type Record<string, unknown>. TypeScript therefore infers no spec shape from the context. typedSpec(...) is the mechanism that starts the check where you write the spec. ViewMeta holds no viewKey and no viewParts: the derivation stamps those fields, and it overwrites a value from an author without a notice. Therefore the compiler refuses them here.

The check of an excess property works on an inline object literal only. For a spec in a variable, or for a spec from a spread, write satisfies ViewMeta at the literal instead.

At run time this function does nothing: it returns the spec object without a change.

Parameters

Parameter	Type
spec	ViewMeta

Returns

ViewMeta

Example

meta: {
  view: typedSpec({
    root: "root",
    elements: {
      root: {
        type: "Dashboard",
        props: { username: { $state: "/context/username" } },
        children: [],
      },
    },
  }),
}