Function replaceObservation

packages/core/src/system-context/index.ts:287–291

(entries: ReadonlyArray<Entry>, previous: Snapshot)

}

function replaceObservation(entries: ReadonlyArray<Entry>, previous: Snapshot): ReplacementResult {
  if (entries.some((entry) => entry._tag === "Unavailable" && getSnapshot(previous, entry.key) !== undefined))
    return { _tag: "ReplacementBlocked" }
  return { _tag: "ReplacementReady", generation: initializeObservation(entries) }
}

function context(sources: ReadonlyArray<PackedSource>): SystemContext {
  return { [ContextTypeId]: sources }