DefinitelyTyped/koa-json-error/index.d.ts

// Type definitions for koa-json-error v3.x
// Project: https://github.com/koajs/json-error
// Definitions by: Mudkip <https://github.com/mudkipme>
// Definitions: https://github.com/mudkipme/DefinitelyTyped

import * as Koa from "koa";

interface JSONErrorOptions {
    /**
     * Perform some task before calling `options.format`. Must be a function with the original err as its only argument.
     */
    preFormat?: { (err: Error): any };

    /**
     * Runs inmediatly after `options.preFormat`. It receives two arguments: the original `err` and the output of     `options.preFormat`. It should `return` a newly formatted error.
     */
    format?: { (err: Error, obj: any): any };

    /**
     * Runs inmediatly after `options.format`. It receives two arguments: the original `err` and the output of   `options.format`.   It should `return` a newly formatted error.
     */
    postFormat?: { (err: Error, obj: any): any };
}

/**
 * Error handler for pure Koa 2.0.0+ JSON apps
 */
declare function jsonError(options?: JSONErrorOptions) : { (ctx: Koa.Context, next?: () => any): any };

declare namespace jsonError {}
export = jsonError;