-import crypto from 'crypto';
+import crypto from 'node:crypto';
+import util from 'node:util';
-import { WebSocketCloseEventStatusString } from '../types/WebSocket';
+import clone from 'just-clone';
-export default class Utils {
+import { Constants } from './Constants';
+import { WebSocketCloseEventStatusString } from '../types';
+
+export class Utils {
private constructor() {
// This is intentional
}
- public static logPrefix(prefixString = ''): string {
- return new Date().toLocaleString() + prefixString;
- }
+ public static logPrefix = (prefixString = ''): string => {
+ return `${new Date().toLocaleString()}${prefixString}`;
+ };
public static generateUUID(): string {
return crypto.randomUUID();
let secondsStr = seconds.toString();
if (hours < 10) {
- hoursStr = '0' + hours.toString();
+ hoursStr = `0${hours.toString()}`;
}
if (minutes < 10) {
- minutesStr = '0' + minutes.toString();
+ minutesStr = `0${minutes.toString()}`;
}
if (seconds < 10) {
- secondsStr = '0' + seconds.toString();
+ secondsStr = `0${seconds.toString()}`;
}
- return hoursStr + ':' + minutesStr + ':' + secondsStr.substring(0, 6);
+ return `${hoursStr}:${minutesStr}:${secondsStr.substring(0, 6)}`;
}
public static formatDurationSeconds(duration: number): string {
return Utils.formatDurationMilliSeconds(duration * 1000);
}
- public static convertToDate(value: unknown): Date {
- // Check
- if (!value) {
- return value as Date;
+ public static convertToDate(
+ value: Date | string | number | null | undefined
+ ): Date | null | undefined {
+ if (Utils.isNullOrUndefined(value)) {
+ return value as null | undefined;
+ }
+ if (value instanceof Date) {
+ return value;
}
- // Check Type
- if (!(value instanceof Date)) {
- return new Date(value as string);
+ if (Utils.isString(value) || typeof value === 'number') {
+ return new Date(value);
}
- return value;
+ return null;
}
public static convertToInt(value: unknown): number {
- let changedValue: number = value as number;
if (!value) {
return 0;
}
+ let changedValue: number = value as number;
if (Number.isSafeInteger(value)) {
return value as number;
}
- // Check
+ if (typeof value === 'number') {
+ return Math.trunc(value);
+ }
if (Utils.isString(value)) {
- // Create Object
changedValue = parseInt(value as string);
}
+ if (isNaN(changedValue)) {
+ throw new Error(`Cannot convert to integer: ${value.toString()}`);
+ }
return changedValue;
}
public static convertToFloat(value: unknown): number {
- let changedValue: number = value as number;
if (!value) {
return 0;
}
- // Check
+ let changedValue: number = value as number;
if (Utils.isString(value)) {
- // Create Object
changedValue = parseFloat(value as string);
}
+ if (isNaN(changedValue)) {
+ throw new Error(`Cannot convert to float: ${value.toString()}`);
+ }
return changedValue;
}
public static convertToBoolean(value: unknown): boolean {
let result = false;
- // Check boolean
if (value) {
// Check the type
if (typeof value === 'boolean') {
- // Already a boolean
- result = value;
- } else {
- // Convert
- result = value === 'true';
+ return value;
+ } else if (
+ Utils.isString(value) &&
+ ((value as string).toLowerCase() === 'true' || value === '1')
+ ) {
+ result = true;
+ } else if (typeof value === 'number' && value === 1) {
+ result = true;
}
}
return result;
}
- public static getRandomFloat(max = Number.MAX_VALUE, min = 0, negative = false): number {
- if (max < min || max < 0 || min < 0) {
+ public static getRandomFloat(max = Number.MAX_VALUE, min = 0): number {
+ if (max < min) {
throw new RangeError('Invalid interval');
}
- const randomPositiveFloat = crypto.randomBytes(4).readUInt32LE() / 0xffffffff;
- const sign = negative && randomPositiveFloat < 0.5 ? -1 : 1;
- return sign * (randomPositiveFloat * (max - min) + min);
- }
-
- public static getRandomInteger(max = Number.MAX_SAFE_INTEGER, min = 0): number {
- if (max < min || max < 0 || min < 0) {
+ if (max - min === Infinity) {
throw new RangeError('Invalid interval');
}
+ return (crypto.randomBytes(4).readUInt32LE() / 0xffffffff) * (max - min) + min;
+ }
+
+ public static getRandomInteger(max = Constants.MAX_RANDOM_INTEGER, min = 0): number {
max = Math.floor(max);
if (!Utils.isNullOrUndefined(min) && min !== 0) {
min = Math.ceil(min);
- return Math.floor(Utils.secureRandom() * (max - min + 1)) + min;
+ return Math.floor(crypto.randomInt(min, max + 1));
}
- return Math.floor(Utils.secureRandom() * (max + 1));
+ return Math.floor(crypto.randomInt(max + 1));
}
public static roundTo(numberValue: number, scale: number): number {
);
}
- public static cloneObject<T>(object: T): T {
- return JSON.parse(JSON.stringify(object)) as T;
+ public static isObject(item: unknown): boolean {
+ return (
+ Utils.isNullOrUndefined(item) === false &&
+ typeof item === 'object' &&
+ Array.isArray(item) === false
+ );
+ }
+
+ public static cloneObject<T extends object>(object: T): T {
+ return clone<T>(object);
+ }
+
+ public static hasOwnProp(object: unknown, property: PropertyKey): boolean {
+ return Utils.isObject(object) && Object.hasOwn(object as object, property);
+ }
+
+ public static isCFEnvironment(): boolean {
+ return !Utils.isNullOrUndefined(process.env.VCAP_APPLICATION);
}
public static isIterable<T>(obj: T): boolean {
- return obj ? typeof obj[Symbol.iterator] === 'function' : false;
+ return !Utils.isNullOrUndefined(obj) ? typeof obj[Symbol.iterator] === 'function' : false;
}
public static isString(value: unknown): boolean {
}
public static isEmptyString(value: unknown): boolean {
- return Utils.isString(value) && (value as string).trim().length === 0;
+ return (
+ Utils.isNullOrUndefined(value) ||
+ (Utils.isString(value) && (value as string).trim().length === 0)
+ );
+ }
+
+ public static isNotEmptyString(value: unknown): boolean {
+ return Utils.isString(value) && (value as string).trim().length > 0;
}
public static isUndefined(value: unknown): boolean {
- return typeof value === 'undefined';
+ return value === undefined;
}
public static isNullOrUndefined(value: unknown): boolean {
// eslint-disable-next-line eqeqeq, no-eq-null
- return value == null ? true : false;
+ return value == null;
}
- public static isEmptyArray(object: unknown | unknown[]): boolean {
- if (!Array.isArray(object)) {
- return true;
- }
- if (object.length > 0) {
- return false;
- }
- return true;
+ public static isEmptyArray(object: unknown): boolean {
+ return Array.isArray(object) && object.length === 0;
+ }
+
+ public static isNotEmptyArray(object: unknown): boolean {
+ return Array.isArray(object) && object.length > 0;
}
public static isEmptyObject(obj: object): boolean {
- if (Utils.isNullOrUndefined(obj)) {
+ if (obj?.constructor !== Object) {
return false;
}
// Iterates over the keys of an object, if
`${str.slice(0, pos)}${subStr}${str.slice(pos)}`;
/**
- * @param [retryNumber=0]
+ * @param retryNumber - the number of retries that have already been attempted
* @returns delay in milliseconds
*/
- public static exponentialDelay(retryNumber = 0): number {
+ public static exponentialDelay(retryNumber = 0, maxDelayRatio = 0.2): number {
const delay = Math.pow(2, retryNumber) * 100;
- const randomSum = delay * 0.2 * Utils.secureRandom(); // 0-20% of the delay
+ const randomSum = delay * maxDelayRatio * Utils.secureRandom(); // 0-20% of the delay
return delay + randomSum;
}
+ public static isPromisePending(promise: Promise<unknown>): boolean {
+ return util.inspect(promise).includes('pending');
+ }
+
public static async promiseWithTimeout<T>(
promise: Promise<T>,
timeoutMs: number,
// Create a timeout promise that rejects in timeout milliseconds
const timeoutPromise = new Promise<never>((_, reject) => {
setTimeout(() => {
- timeoutCallback();
+ if (Utils.isPromisePending(promise)) {
+ timeoutCallback();
+ // FIXME: The original promise shall be canceled
+ }
reject(timeoutError);
}, timeoutMs);
});
}
public static JSONStringifyWithMapSupport(
- obj: Record<string, unknown> | Record<string, unknown>[],
+ obj: Record<string, unknown> | Record<string, unknown>[] | Map<unknown, unknown>,
space?: number
): string {
return JSON.stringify(
/**
* Convert websocket error code to human readable string message
*
- * @param code websocket error code
+ * @param code - websocket error code
* @returns human readable string message
*/
public static getWebSocketCloseEventStatusString(code: number): string {
}
return '(Unknown)';
}
+
+ public static median(dataSet: number[]): number {
+ if (Utils.isEmptyArray(dataSet)) {
+ return 0;
+ }
+ if (Array.isArray(dataSet) === true && dataSet.length === 1) {
+ return dataSet[0];
+ }
+ const sortedDataSet = dataSet.slice().sort((a, b) => a - b);
+ return (
+ (sortedDataSet[(sortedDataSet.length - 1) >> 1] + sortedDataSet[sortedDataSet.length >> 1]) /
+ 2
+ );
+ }
+
+ // TODO: use order statistics tree https://en.wikipedia.org/wiki/Order_statistic_tree
+ public static percentile(dataSet: number[], percentile: number): number {
+ if (percentile < 0 && percentile > 100) {
+ throw new RangeError('Percentile is not between 0 and 100');
+ }
+ if (Utils.isEmptyArray(dataSet)) {
+ return 0;
+ }
+ const sortedDataSet = dataSet.slice().sort((a, b) => a - b);
+ if (percentile === 0 || sortedDataSet.length === 1) {
+ return sortedDataSet[0];
+ }
+ if (percentile === 100) {
+ return sortedDataSet[sortedDataSet.length - 1];
+ }
+ const percentileIndexBase = (percentile / 100) * (sortedDataSet.length - 1);
+ const percentileIndexInteger = Math.floor(percentileIndexBase);
+ if (!Utils.isNullOrUndefined(sortedDataSet[percentileIndexInteger + 1])) {
+ return (
+ sortedDataSet[percentileIndexInteger] +
+ (percentileIndexBase - percentileIndexInteger) *
+ (sortedDataSet[percentileIndexInteger + 1] - sortedDataSet[percentileIndexInteger])
+ );
+ }
+ return sortedDataSet[percentileIndexInteger];
+ }
+
+ public static stdDeviation(dataSet: number[]): number {
+ let totalDataSet = 0;
+ for (const data of dataSet) {
+ totalDataSet += data;
+ }
+ const dataSetMean = totalDataSet / dataSet.length;
+ let totalGeometricDeviation = 0;
+ for (const data of dataSet) {
+ const deviation = data - dataSetMean;
+ totalGeometricDeviation += deviation * deviation;
+ }
+ return Math.sqrt(totalGeometricDeviation / dataSet.length);
+ }
}