One potential issue is with a model that may be in an incorrect state, where we can examine the errors using model.getErrors(). These errors are stored in a map that includes keys of a certain type keyof D, as well as a special key called base.
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export type Errors<D> = {
readonly [K in (keyof D | 'base')]?: string[]
}
class Model<D> {
getErrors(): Errors<D> {
return { base: ['some base error'] }
}
}