ayakashi/lib/prelude/actions/retry.js

The next generation web scraping framework

"use strict";
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
    return new (P || (P = Promise))(function (resolve, reject) {
        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
        step((generator = generator.apply(thisArg, _arguments || [])).next());
    });
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.attachRetry = void 0;
const async_1 = require("async");
const backoff_1 = require("backoff");
const opLog_1 = require("../../opLog/opLog");
const path_1 = require("path");
function attachRetry(ayakashiInstance) {
    const opLog = opLog_1.getOpLog();
    //@ts-ignore
    ayakashiInstance.retry = function (task, retries = 10) {
        return __awaiter(this, void 0, void 0, function* () {
            if (!task || typeof task !== "function") {
                throw new Error("<retry> requires a function to run");
            }
            if (retries <= 0) {
                //tslint:disable no-parameter-reassignment
                retries = 10;
                //tslint:enable
            }
            let retried = 0;
            const strategy = new backoff_1.ExponentialStrategy({
                randomisationFactor: 0.5,
                initialDelay: 500,
                maxDelay: 5000,
                factor: 2
            });
            const errForStack = new Error();
            Error.captureStackTrace(errForStack, ayakashiInstance.retry);
            let filename = "";
            if (errForStack && errForStack.stack) {
                const stackMatch = errForStack.stack.match(/\/([\/\w-_\.]+\.js):(\d*):(\d*)/);
                if (stackMatch && stackMatch[0]) {
                    filename = stackMatch[0].split(path_1.sep).pop() || "";
                }
            }
            return new Promise(function (resolve, reject) {
                async_1.retry({
                    times: retries,
                    interval: function () {
                        return strategy.next();
                    }
                }, function (cb) {
                    let taskResult;
                    taskResult = task(retried + 1);
                    if (taskResult instanceof Promise) {
                        taskResult
                            .then(function (result) {
                            cb(null, result);
                        })
                            .catch(function (err) {
                            retried += 1;
                            console.error(err);
                            if (retried < retries) {
                                opLog.warn(`operation ${filename} will be retried -`, `retries: ${retried}/${retries}`);
                            }
                            else {
                                opLog.error(`${retries} retries reached for ${filename} - operation will fail`);
                            }
                            cb(err);
                        });
                    }
                    else {
                        reject(new Error("<retry> requires an async function that returns a promise"));
                    }
                }, function (err, result) {
                    if (err) {
                        reject(err);
                    }
                    else {
                        resolve(result);
                    }
                });
            });
        });
    };
}
exports.attachRetry = attachRetry;