import { Config } from "./Config";
import { TransformFunction } from "./common";
/**
 * Creates a function for applying a user-defined transformation to
 * file contents.
 */
export declare class ContentTransformer {
    private readonly callback;
    private readonly encoding;
    private readonly thisArg;
    static fromConfig(config: Config): ContentTransformer;
    constructor(callback: Function, encoding: string | null, thisArg: any);
    makeTransformFunction(): TransformFunction;
    private transform(contents, file);
    private decodeContents(contents);
    private invokeAndValidate(decodedContents, file);
    private tryInvokeCallback(decodedContents, file);
}