import { IReporter } from './reporters';
import { RunFunction, IBenchmarkCase } from './suite';
import { MaybeAsync } from './async';
import { IOptions } from './options';
/**
 * A middleware function for the benchmark. Invoked directly before the
 * benchmark starts running.
 */
export declare type Middleware = (benchmark: Readonly<IBenchmarkCase>, next: (options: Readonly<IBenchmarkCase>) => Promise<void>) => Promise<void>;
/**
 * Options passed to the `benchmark` function.
 */
export interface IBenchmarkOptions {
    /**
     * Optional funciton to override how benchmarks are run. Useful mostly
     * for testing purposes.
     */
    runFunction?: RunFunction;
    /**
     * Optional profiler instance that can be used to run CPU profiles
     * on benchmarks.
     */
    middleware?: Middleware[];
    /**
     * Takes the benchmark API, and should register all benchmarks using
     * the `api.bench()` method before turning.
     */
    prepare: (setupFn: IBenchmarkApi) => Promise<void> | void;
    /**
     * Reporter to use for returning results.
     */
    reporter: IReporter;
}
/**
 * API passed to the prepare step of the benchmarking.
 */
export interface IBenchmarkApi {
    /**
     * Adds the given function to the benchmark.
     * @param name Benchmark name
     * @param fn Function to run, can return a promise or call a callback
     * @param options Benchmark options for benchmark.js. Note that setup and
     * teardown are allowed to be async, however!
     */
    bench(name: string, fn: MaybeAsync, options?: IOptions): void;
    /**
     * Creates a nested 'scope' of benchmarks. Options are inherited and
     * names are prefixed with the suite name.
     */
    suite(name: string, fn: () => void, options?: IOptions): void;
    /**
     * Sets an option for all benchmarks in the current suite and nested suites.
     */
    set<K extends keyof IOptions>(key: K, value: IOptions[K]): void;
    /**
     * A stub function that 'uses' the value, preventing it from being optimized
     * away.
     */
    retain(value: unknown): void;
}
export declare function benchmark({ runFunction, prepare, reporter, middleware, }: IBenchmarkOptions): Promise<void>;