/**
 * Parse a JSON string if defined, otherwise return the default value.
 * This is useful for parsing JSON strings from database storage.
 */
export declare function parseJsonIfDefined<T>(value: string | null | undefined, defaultValue: T): T;
/**
 * Parse a JSON metadata blob from the database. Returns the parsed value
 * only if it's a plain object (rejects arrays, primitives, and parse errors)
 * — those would be corruption or legacy rows we don't want to crash on.
 */
export declare function parseJsonObjectIfDefined(value: string | null | undefined): Record<string, unknown> | undefined;
/**
 * Parse multiple JSON string properties of an object.
 * Properties that are undefined or null will use their default values.
 *
 * @param obj - The source object containing JSON string properties to parse
 * @param propertyDefaults - Map of property names to their default values
 * @param target - The target object to write parsed values to (defaults to a new object based on obj)
 * @returns The target object with parsed properties
 *
 * @example
 * const source = { flags: '{"enabled":true}', sessions: null, name: "Test" };
 * const result = parseJsonProperties(source, { flags: {}, sessions: {} });
 * // result = { flags: {enabled: true}, sessions: {}, name: "Test" }
 */
export declare function parseJsonProperties<T extends Record<string, any>>(obj: T, propertyDefaults: Partial<Record<keyof T, any>>, target?: any): any;