EmptyEventMap
typeThe event map a spec contributes when it declares none.
Record<never, never> rather than {}: the bare empty-object type accepts any non-nullish
value, including 0 and "", so it would let nonsense through Merge. This has no
keys, which is the actual claim being made, and Merge short-circuits on it.Definition
type
type EmptyEventMap = Record<never, never>Record<never, never>