import type { NestedKey } from './style.spec.js';
import type { Properties } from 'gis-tools/index.js';
/**
 * Coalesce text layout property "field"
 *
 * examples:
 *
 * ```ts
 * // example 1
 * const properties = { abbr: 'U.S.', name: 'United States', ... }
 * const field = ["\"", "?abbr,?name", "\""] // here we coallese to abbr if the property exists, otherwise we fallback on name
 * cooalesceField(field) // returns "U.S." or "United States" depending on whether abbr exists
 *
 * // example 2
 * const properties = { type: 'airplane', ... }
 * const field = ["?type", "-16"]
 * cooalesceField(field) // 'airplane-16'
 * ```
 * @param field - string field, array of string fields, or nested key
 * @param properties - properties to coalesce
 * @param fieldIsKey - whether the field is the key in properties or a value to coalesce
 * @returns the coalesced field
 */
export default function coalesceField(field: string | string[] | NestedKey, properties: Properties, fieldIsKey?: boolean): string;