Function unionOrUndefined

src/spec-node/imageMetadata.ts:280–283

(entries: (T[] | undefined)[])

}

function unionOrUndefined<T>(entries: (T[] | undefined)[]): T[] | undefined {
	const values = [...new Set(([] as T[]).concat(...entries.filter(entry => !!entry) as T[][]))];
	return values.length ? values : undefined;
}

function collectOrUndefined<T, K extends keyof T>(entries: T[], property: K): NonNullable<T[K]>[] | undefined {
	const values = entries.map(entry => entry[property])