/// <reference types="node" />
import { DiffOptions } from '../../types';
export default function (getExpected: (imageName?: string) => Promise<{
    expected: Buffer | null;
    onCompare: (actual: Buffer, expect?: Buffer, diff?: Buffer) => Promise<void>;
} | Buffer | null>, diffOptions: DiffOptions): ({ Assertion }: Chai.ChaiStatic, utils: Chai.ChaiUtils) => void;