@handy-common-utils/misc-utils

Miscellaneous utilities for JavaScript/TypeScript development.

Features

This package provides several utility categories:

Array manipulation (distribution and sampling)
String encoding related utilities
Error classification helpers
HTTP status codes and messages
Line-based logging
String masking for sensitive data
JSON stringify replacers
String substitution utilities

Installation

npm install @handy-common-utils/misc-utils

Quick Examples

Array Utilities

import { distributeRoundRobin, downSampleRandomly } from '@handy-common-utils/misc-utils';

// Distribute items evenly across groups
const items = [1, 2, 3, 4, 5, 6];
const groups = distributeRoundRobin(items, 3);
// Result: [[1,4], [2,5], [3,6]]

// Random sampling
const sample = downSampleRandomly(items, 3);
// Gets 3 random items while maintaining relative order

Encoding of Strings

import { 
  shortBase64UrlFromUInt32,
  generateRandomString 
} from '@handy-common-utils/misc-utils';

// Convert number to URL-safe base64
const urlSafeId = shortBase64UrlFromUInt32(12345);

// Generate random string (cryptographically strong)
const randomId = generateRandomString(16);
// Generate random string (no cryptographic strength)
const randomId2 = generateRandomStringQuickly(16);

Error Classification

import {
  couldBeNetworkingTimeoutError,
  couldBeServerError,
  couldBeTemporaryNetworkingError
} from '@handy-common-utils/misc-utils';

try {
  await fetchData();
} catch (error) {
  if (couldBeTemporaryNetworkingError(error)) {
    // Retry logic
  }
  if (couldBeServerError(error)) {
    // Log server error
  }
}

Line Logger

 // use chalk (chalk is not a dependency of this package, you need to add chalk as a dependency separately)
 import chalk from 'chalk';
 import { LineLogger } from '@handy-common-utils/misc-utils';

 // this.flags is an object with properties "debug" and "quiet"
 this.output = LineLogger.consoleWithColour(this.flags, chalk);
 this.output.warn('Configuration file not found, default configuration would be used.');  // it would be printed out in yellow

String Masking

import { mask, maskAll, maskEmail, maskFullName, pathBasedReplacer } from '@handy-common-utils/misc-utils';

const masked = JSON.stringify(obj, pathBasedReplacer([
  [/(^|\.)x-api-key$/i, maskAll],
  [/(^|\.)customer\.name$/i, maskFullName],
  [/(^|\.)customer\..*[eE]mail$/i, maskEmail],
  [/(^|\.)zip$/i, (value: string) => value.slice(0, 3) + 'XX'],
  [/(^|\.)cc$/i, () => undefined],
  [/(^|\.)ssn$/i, mask],
]));

JSON Stringify with Replacers

import { pathBasedReplacer } from '@handy-common-utils/misc-utils';

const data = {
  user: {
    name: 'John Smith',
    email: 'john@example.com',
    ssn: '123-45-6789',
    creditCard: '4111-1111-1111-1111'
  }
};

const replacer = pathBasedReplacer([
  [/\.name$/, maskFullName],
  [/\.email$/, maskEmail],
  [/\.ssn$/, maskAll],
  [/\.creditCard$/, maskCreditCard]
]);

console.log(JSON.stringify(data, replacer, 2));

String Substitution

import { substituteAll } from '@handy-common-utils/misc-utils';

// Template substitution
const template = 'Hello, {name}! Your order #{orderId} is ready.';
const values = { name: 'John', orderId: '12345' };
const result = substituteAll(template, /{([^{}]+)}/g, (_, groups) => {
  return values[groups[1]] || '';
});
// Result: "Hello, John! Your order #12345 is ready."

String Utilities

import {
  truncate,
  capitalize,
  capitalise,
  camelToSnake,
  snakeToCamel,
  pluralize,
  pluralise,
  applyWordCasing
} from '@handy-common-utils/misc-utils';

// Truncate a string
truncate('hello world', 8); // 'hello...'
truncate('hello world', 8, '!'); // 'hello w!'

// Capitalize/capitalise
capitalize('hELLo'); // 'Hello'
capitalise('hELLo'); // 'Hello'

// Convert camelCase to snake_case
camelToSnake('helloWorld'); // 'hello_world'
camelToSnake('JSONData'); // 'json_data'

// Convert snake_case to camelCase
snakeToCamel('hello_world'); // 'helloWorld'
snakeToCamel('hello__world'); // 'helloWorld'

// Pluralize words
pluralize('cat', 2); // 'cats'
pluralise('person', 2); // 'people'
pluralize('fish', 2); // 'fish'

// Preserve casing from template
applyWordCasing('CAT', 'dog'); // 'DOG'
applyWordCasing('Cat', 'dog'); // 'Dog'

Number Utilities

import { clamp, isInRange, roundTo } from '@handy-common-utils/misc-utils';

// Clamp a number within a range
clamp(5, 0, 10); // 5
clamp(-5, 0, 10); // 0
clamp(15, 0, 10); // 10

// Check if a number is in range
isInRange(5, 0, 10); // true
isInRange(15, 0, 10); // false

// Round to decimal places
roundTo(3.14159, 2); // 3.14
roundTo(123.456, -1); // 120

Masking

In software development, it's often necessary to hide sensitive information to protect user privacy or comply with regulations. Masking is a common technique used to replace part of a sensitive value with a different, non-sensitive value. For example, you might mask credit card numbers, passwords, or email addresses.

The mask(input, keepLeft = 1, keepRight = 0, minLength = 3, maskLengthOrMaskString = null, maskPattern = '*') function can be used to mask the content of a string, replacing a part of the input string with a mask string. It takes several optional parameters, including the number of characters to keep on the left and right sides of the string, a minimum length for the input string to have unmask characters kept, and the mask pattern to use. The maskEmail(input) and maskFullName(input) functions are specific variations of the mask function that target email addresses and full names, respectively. The maskAll(input) function masks all characters.

expect(mask(undefined)).to.be.undefined;
expect(mask(null)).to.be.null;
expect(mask('')).to.equal('');

expect(mask('abcde')).to.equal('a****');
expect(mask('abc')).to.equal('a**');
expect(mask('ab')).to.equal('**');

expect(maskEmail('james.hu@address.com')).to.equal('j****.**@address.com');
expect(maskEmail('her@here.com')).to.equal('h**@here.com');
expect(maskEmail('me@here.com')).to.equal('**@here.com');
expect(maskEmail('my.new.email.address@example.com')).to.equal('**.n**.e****.a******@example.com');

expect(maskFullName('James Hu')).to.equal('J**** **');
expect(maskFullName('John Smith')).to.equal('J*** S****');
expect(maskFullName('Mike')).to.equal('M***');
expect(maskFullName('Mia')).to.equal('M**');
expect(maskFullName('Me')).to.equal('**');
expect(maskFullName('John von Neumann')).to.equal('J*** v** N******');
expect(maskFullName('Two  Spaces')).to.equal('T**  S*****');
expect(maskFullName('张三丰')).to.equal('张**');
expect(maskFullName('张三')).to.equal('**');

Replacers for JSON.stringify(input, replacer, space)

The pathAwareReplacer(replacer, options) function allows you to build a replacer function that can be passed to JSON.stringify(input, replacer, space). Besides the key, value, and owning object, it also exposes more information to your callback function, such like the full property path as both a dot (.) separated string and as an array, and an array of ancestor objects. This can be useful when you need to replace specific values in an object, but you also want to know where those values were located in the object.

pathBasedReplacer is a function that takes an array of path-based masking rules and returns a function that can be used as the second parameter in the JSON.stringify function. This function allows you to mask sensitive information during JSON.stringify in a very flexible way.

Each element in the rules array contains two parts: a regular expression that matches the full paths to the values you want to mask or replace, and a masking or replacing function that takes the original value as input and returns the masked or replaced value.

For example, you could use pathBasedReplacer to replace all credit card numbers in an object with masked versions of the numbers:

const maskCreditCard = (value: any) => "****-****-****-" + value.slice(-4);

const replacer = pathBasedReplacer([
  [/(^|\.)billing\.cc$/i, maskCreditCard]
]);

const json = JSON.stringify({
  to: 'auditor@example.com',
  cc: 'auditing-trail@example.com',
  year: 2023,
  month: 2,
  orders: [
    {
      id: 123,
      billing: {
        address: '19 High Street',
        cc: '1234-5678-2222-3333',
      },
    },
    {
      id: 124,
      billing: {
        address: '88 Main Street',
        cc: '3435-8933-0009-2241',
      },
    },
  ],
}, replacer, 2);

// Combining multiple path based replaces
const replacer2 = pathBasedReplacer([
  ...
]);
const combinedReplacer = pathBasedReplacer([...replacer.rules, ...replacer2.rules]);

substituteAll

The substituteAll(input, searchPattern, substitute) function allows you to perform substitutions on an input string by matching a specified pattern and replacing the matches with substitution strings built by a function. It provides flexibility in handling complex substitution scenarios through the substitute callback function.

Example Usage Scenarios:

Templating: Replace placeholder variables in a template string with dynamic values. For example, transforming the template "Hello, {name}! How are you, {name}? I am {me}." into "Hello, John! How are you, John? I am James." by substituting {name} with the value "John" and {me} with value "James".

const input = 'Hello, {name}! How are you, {name}? I am {me}.';
const searchPattern = /{([^{}]+)}/g;
const dict: Record<string, string> = {
  name: 'John',
  me: 'James',
};
const substitute: Parameters<typeof substituteAll>[2] = (_match, result) => {
  const key = result[1];
  return dict[key] ?? `{NOT FOUND: ${key}}`;
};
const result = substituteAll(input, searchPattern, substitute);

Text Transformation: Modify specific segments of a string based on predefined patterns. For instance, converting dates written in a non-standard format, such as "MM/DD/YY", to a standardized format, like "YYYY-MM-DD", using a suitable regular expression pattern and substitution logic.

const input = 'Event date: 12/31/21';
const searchPattern = / ((\d{2})\/(\d{2})\/(\d{2}))/g;
const substitute = (_: string, result: any) => {
  const [match, date, month, day, year] = result;
  const formattedDate = `20${year}-${month}-${day}`;
  return match.replace(date, formattedDate);
};

const result = substituteAll(input, searchPattern, substitute);

API

@handy-common-utils/misc-utils

Modules

Module	Description
array	-
codec	-
errors	-
http-status	-
index	-
line-logger	-
mask	-
merge	-
number	-
string	-
stringify-replacer	-
substitute	-

Array

array

Functions

Function	Description
distributeRoundRobin	Distributes an array into a number of groups in a round robin fashion. This function has been tuned for performance.
downSampleRandomly	Down samples the input array randomly.

Functions

Function: distributeRoundRobin()

distributeRoundRobin<T>(array, groups): T[][]

Distributes an array into a number of groups in a round robin fashion. This function has been tuned for performance.

Type Parameters

Type Parameter
`T`

Parameters

Parameter	Type	Description
`array`	`T`[]	The input array
`groups`	`number`	Number of groups the elements in the input array need to be distributed into.

Returns

T[][]

The result as an array of arrays which each represents a group

Function: downSampleRandomly()

downSampleRandomly<T>(array, numSamples, probabilityTransformerFunction): T[]

Down samples the input array randomly.

Type Parameters

Type Parameter
`T`

Parameters

Parameter	Type	Description
`array`	`T`[]	The input array
`numSamples`	`number`	Number of samples to be taken from the input array. If the number of samples is greater than or equal to the length of the input array, the output array will contain all the elements in the input array.
`probabilityTransformerFunction`	(`x`) => `number`	A function that turns a random number within [0, 1) to another number within [0, 1). If not provided, the identity function F(x) = x will be used. The probability of an element being selected from the input array is determined by this function.

Returns

T[]

A new array with the down sampled elements from the input array. The order of the elements in the output array is the same as the input array.

Codec

codec

Functions

Function	Description
base64FromUInt32	Encode an unsigned 32-bit integer into BASE64 string.
base64UrlFromUInt32	Encode an unsigned 32-bit integer into URL/path safe BASE64 string.
escapeForRegExp	Escape a string literal for using it inside of RegExp. (From: https://stackoverflow.com/questions/3446170/escape-string-for-use-in-javascript-regex)
escapeForRegExpReplacement	Escape replacement string for using it inside of RegExp replacement parameter. (From: https://stackoverflow.com/questions/3446170/escape-string-for-use-in-javascript-regex)
generateRandomString	Generate a strong (using crypto.randomFillSync(...)) random string that is URL/path safe. In the generated string, approximately every 6 characters represent randomly generated 32 bits. For example, if you need 128 bits of randomness, you just need to generate a string containing 24 characters.
generateRandomStringQuickly	Generate a weak (using Math.random()) random string that is URL/path safe. In the generated string, approximately every 6 characters represent randomly generated 32 bits. For example, if you need 128 bits of randomness, you just need to generate a string containing 24 characters.
shortBase64FromUInt32	Encode an unsigned 32-bit integer into BASE64 string without trailing '='.
shortBase64UrlFromUInt32	Encode an unsigned 32-bit integer into URL/path safe BASE64 string without trailing '='.
urlSafe	Make a "normal" (BASE64) string URL/path safe.

Functions

Function: base64FromUInt32()

base64FromUInt32<T>(ui32): string | Exclude<T, number>

Encode an unsigned 32-bit integer into BASE64 string.

Type Parameters

Type Parameter
`T` extends `number` \| `null` \| `undefined`

Parameters

Parameter	Type	Description
`ui32`	`T`	A 32-bit integer number which could also be null or undefined. It must be a valid unsigned 32-bit integer. Behavior is undefined when the value is anything other than an unsigned 32-bit integer. If you don't care about loosing precision, you can convert a number by doing `n >>> 0` (See https://stackoverflow.com/questions/22335853/hack-to-convert-javascript-number-to-uint32)

Returns

string | Exclude<T, number>

BASE64 string representing the integer input, or the original input if it is null or undefined.

Function: base64UrlFromUInt32()

base64UrlFromUInt32<T>(ui32, replacements): string | Exclude<T, number>

Encode an unsigned 32-bit integer into URL/path safe BASE64 string.

Type Parameters

Type Parameter
`T` extends `number` \| `null` \| `undefined`

Parameters

Parameter	Type	Default value	Description
`ui32`	`T`	`undefined`	A 32-bit integer number which could also be null or undefined. It must be a valid unsigned 32-bit integer. Behavior is undefined when the value is anything other than an unsigned 32-bit integer. If you don't care about loosing precision, you can convert a number by doing `n >>> 0` (See https://stackoverflow.com/questions/22335853/hack-to-convert-javascript-number-to-uint32)
`replacements`	`string`	`'_-='`	A string containing replacement characters for "/", "+", and "=". If omitted, default value of '_-=' would be used.

Returns

string | Exclude<T, number>

URL/path safe BASE64 string representing the integer input, or the original input if it is null or undefined.

Function: escapeForRegExp()

escapeForRegExp(text): string

Escape a string literal for using it inside of RegExp. (From: https://stackoverflow.com/questions/3446170/escape-string-for-use-in-javascript-regex)

Parameters

Parameter	Type	Description
`text`	`string` \| `null` \| `undefined`	the string literal to be escaped

Returns

string

escaped string that can be used inside of RegExp, or an empty string if the input is null or undefined

Function: escapeForRegExpReplacement()

escapeForRegExpReplacement(text): string

Escape replacement string for using it inside of RegExp replacement parameter. (From: https://stackoverflow.com/questions/3446170/escape-string-for-use-in-javascript-regex)

Parameters

Parameter	Type	Description
`text`	`string` \| `null` \| `undefined`	the replacement string to be escaped, or an empty string if the input is null or undefined

Returns

string

escaped replacement string that can be used inside of RegExp replacement parameter

Function: generateRandomString()

generateRandomString(len): string

Generate a strong (using crypto.randomFillSync(...)) random string that is URL/path safe. In the generated string, approximately every 6 characters represent randomly generated 32 bits. For example, if you need 128 bits of randomness, you just need to generate a string containing 24 characters.

Parameters

Parameter	Type	Description
`len`	`number`	length of the string to be generated

Returns

string

the random string

Function: generateRandomStringQuickly()

generateRandomStringQuickly(len): string

Generate a weak (using Math.random()) random string that is URL/path safe. In the generated string, approximately every 6 characters represent randomly generated 32 bits. For example, if you need 128 bits of randomness, you just need to generate a string containing 24 characters.

Parameters

Parameter	Type	Description
`len`	`number`	length of the string to be generated

Returns

string

the random string

Function: shortBase64FromUInt32()

shortBase64FromUInt32<T>(ui32): string | Exclude<T, number>

Encode an unsigned 32-bit integer into BASE64 string without trailing '='.

Type Parameters

Type Parameter
`T` extends `number` \| `null` \| `undefined`

Parameters

Parameter	Type	Description
`ui32`	`T`	A 32-bit integer number which could also be null or undefined. It must be a valid unsigned 32-bit integer. Behavior is undefined when the value is anything other than an unsigned 32-bit integer. If you don't care about loosing precision, you can convert a number by doing `n >>> 0` (See https://stackoverflow.com/questions/22335853/hack-to-convert-javascript-number-to-uint32)

Returns

string | Exclude<T, number>

BASE64 string without trailing '=' representing the integer input, or the original input if it is null or undefined.

Function: shortBase64UrlFromUInt32()

shortBase64UrlFromUInt32<T>(ui32, replacements): string | Exclude<T, number>

Encode an unsigned 32-bit integer into URL/path safe BASE64 string without trailing '='.

Type Parameters

Type Parameter
`T` extends `number` \| `null` \| `undefined`

Parameters

Parameter	Type	Default value	Description
`ui32`	`T`	`undefined`	A 32-bit integer number which could also be null or undefined. It must be a valid unsigned 32-bit integer. Behavior is undefined when the value is anything other than an unsigned 32-bit integer. If you don't care about loosing precision, you can convert a number by doing `n >>> 0` (See https://stackoverflow.com/questions/22335853/hack-to-convert-javascript-number-to-uint32)
`replacements`	`string`	`'_-'`	A string containing replacement characters for "/" and "+". If omitted, default value of '_-' would be used.

Returns

string | Exclude<T, number>

URL/path safe BASE64 string without trailing '=' representing the integer input, or the original input if it is null or undefined.

Function: urlSafe()

urlSafe<T>(base64Input, replacements): T

Make a "normal" (BASE64) string URL/path safe.

Type Parameters

Type Parameter
`T` extends `string` \| `null` \| `undefined`

Parameters

Parameter	Type	Default value	Description
`base64Input`	`T`	`undefined`	A (BASE64) string which could be null or undefined.
`replacements`	`string`	`'_-='`	A string containing replacement characters for "/", "+", and "=". If omitted, default value of '_-=' would be used.

Returns

T

URL/path safe version of the (BASE64) input string, or the original input if it is null or undefined.

Errors

errors

Functions

Function	Description
couldBeNetworkingTimeoutError	Checks if the error could be a networking timeout error.
couldBeServerError	Checks if the error could be a server error.
couldBeTemporaryNetworkingError	Checks if the error could be a temporary networking error.

Functions

Function: couldBeNetworkingTimeoutError()

couldBeNetworkingTimeoutError(err): boolean

Checks if the error could be a networking timeout error.

Parameters

Parameter	Type	Description
`err`	`unknown`	The error to check.

Returns

boolean

True if the error is a networking timeout error, false otherwise.

Function: couldBeServerError()

couldBeServerError(err): boolean

Checks if the error could be a server error.

Parameters

Parameter	Type	Description
`err`	`unknown`	The error to check.

Returns

boolean

True if the error is a server error, false otherwise.

Function: couldBeTemporaryNetworkingError()

couldBeTemporaryNetworkingError(err): boolean

Checks if the error could be a temporary networking error.

Parameters

Parameter	Type	Description
`err`	`unknown`	The error to check.

Returns

boolean

True if the error is a temporary networking error, false otherwise.

Http Status

http-status

Enumerations

Enumeration	Description
HttpStatusCode	Some (not all) well known HTTP status codes

Variables

Variable	Description
HttpStatusMessage	Some (not all) HTTP status messages matching their codes

Enumerations

Enumeration: HttpStatusCode

Some (not all) well known HTTP status codes

Enumeration Members

Enumeration Member	Value	Description
`ACCEPTED202`	`202`	The request has been received but not yet acted upon. It is non-committal, meaning that there is no way in HTTP to later send an asynchronous response indicating the outcome of processing the request. It is intended for cases where another process or server handles the request, or for batch processing.
`BAD_GATEWAY502`	`502`	This error response means that the server, while working as a gateway to get a response needed to handle the request, got an invalid response.
`BAD_REQUEST400`	`400`	This response means that server could not understand the request due to invalid syntax.
`CONFLICT409`	`409`	This response is sent when a request conflicts with the current state of the server.
`CREATED201`	`201`	The request has succeeded and a new resource has been created as a result of it. This is typically the response sent after a PUT request.
`FORBIDDEN403`	`403`	The client does not have access rights to the content, i.e. they are unauthorized, so server is rejecting to give proper response. Unlike 401, the client's identity is known to the server.
`GATEWAY_TIMEOUT504`	`504`	This error response is given when the server is acting as a gateway and cannot get a response in time.
`INTERNAL_SERVER_ERROR500`	`500`	The server encountered an unexpected condition that prevented it from fulfilling the request.
`METHOD_NOT_ALLOWED405`	`405`	The request method is known by the server but has been disabled and cannot be used. For example, an API may forbid DELETE-ing a resource. The two mandatory methods, GET and HEAD, must never be disabled and should not return this error code.
`MOVED_PERMANENTLY301`	`301`	This response code means that URI of requested resource has been changed. Probably, new URI would be given in the response.
`MOVED_TEMPORARILY302`	`302`	This response code means that URI of requested resource has been changed temporarily. New changes in the URI might be made in the future. Therefore, this same URI should be used by the client in future requests.
`NO_CONTENT204`	`204`	There is no content to send for this request, but the headers may be useful. The user-agent may update its cached headers for this resource with the new ones.
`NOT_FOUND404`	`404`	The server can not find requested resource. In the browser, this means the URL is not recognized. In an API, this can also mean that the endpoint is valid but the resource itself does not exist. Servers may also send this response instead of 403 to hide the existence of a resource from an unauthorized client. This response code is probably the most famous one due to its frequent occurence on the web.
`NOT_IMPLEMENTED501`	`501`	The request method is not supported by the server and cannot be handled. The only methods that servers are required to support (and therefore that must not return this code) are GET and HEAD.
`OK200`	`200`	The request has succeeded. The meaning of a success varies depending on the HTTP method: GET: The resource has been fetched and is transmitted in the message body. HEAD: The entity headers are in the message body. POST: The resource describing the result of the action is transmitted in the message body. TRACE: The message body contains the request message as received by the server
`PERMANENT_REDIRECT308`	`308`	This means that the resource is now permanently located at another URI, specified by the Location: HTTP Response header. This has the same semantics as the 301 Moved Permanently HTTP response code, with the exception that the user agent must not change the HTTP method used: if a POST was used in the first request, a POST must be used in the second request.
`REQUEST_TIMEOUT408`	`408`	This response is sent on an idle connection by some servers, even without any previous request by the client. It means that the server would like to shut down this unused connection. This response is used much more since some browsers, like Chrome, Firefox 27+, or IE9, use HTTP pre-connection mechanisms to speed up surfing. Also note that some servers merely shut down the connection without sending this message.
`SEE_OTHER303`	`303`	Server sent this response to directing client to get requested resource to another URI with an GET request.
`SERVICE_UNAVAILABLE503`	`503`	The server is not ready to handle the request. Common causes are a server that is down for maintenance or that is overloaded. Note that together with this response, a user-friendly page explaining the problem should be sent. This responses should be used for temporary conditions and the Retry-After: HTTP header should, if possible, contain the estimated time before the recovery of the service. The webmaster must also take care about the caching-related headers that are sent along with this response, as these temporary condition responses should usually not be cached.
`TEMPORARY_REDIRECT307`	`307`	Server sent this response to directing client to get requested resource to another URI with same method that used prior request. This has the same semantic than the 302 Found HTTP response code, with the exception that the user agent must not change the HTTP method used: if a POST was used in the first request, a POST must be used in the second request.
`TOO_MANY_REQUESTS429`	`429`	The user has sent too many requests in a given amount of time ("rate limiting").
`UNAUTHORIZED401`	`401`	Although the HTTP standard specifies "unauthorized", semantically this response means "unauthenticated". That is, the client must authenticate itself to get the requested response.

Variables

Variable: HttpStatusMessage

const HttpStatusMessage: object

Some (not all) HTTP status messages matching their codes

Type Declaration

Name	Type	Default value
`200`	`string`	`'OK'`
`201`	`string`	`'Created'`
`202`	`string`	`'Accepted'`
`204`	`string`	`'No Content'`
`301`	`string`	`'Moved Permanently'`
`302`	`string`	`'Moved Temporarily'`
`303`	`string`	`'See Other'`
`307`	`string`	`'Temporary Redirect'`
`308`	`string`	`'Permanent Redirect'`
`400`	`string`	`'Bad Request'`
`401`	`string`	`'Unauthorized'`
`403`	`string`	`'Forbidden'`
`404`	`string`	`'Not Found'`
`405`	`string`	`'Method Not Allowed'`
`408`	`string`	`'Request Timeout'`
`409`	`string`	`'Conflict'`
`429`	`string`	`'Too Many Requests'`
`500`	`string`	`'Internal Server Error'`
`501`	`string`	`'Not Implemented'`
`502`	`string`	`'Bad Gateway'`
`503`	`string`	`'Service Unavailable'`
`504`	`string`	`'Gateway Timeout'`

Index

index

References

capitalise

Re-exports capitalise

capitalize

Re-exports capitalize

clamp

Re-exports clamp

consoleLike

Re-exports consoleLike

ConsoleLineLogger

Re-exports ConsoleLineLogger

consoleWithColour

Re-exports consoleWithColour

consoleWithoutColour

Re-exports consoleWithoutColour

couldBeNetworkingTimeoutError

Re-exports couldBeNetworkingTimeoutError

couldBeServerError

Re-exports couldBeServerError

couldBeTemporaryNetworkingError

Re-exports couldBeTemporaryNetworkingError

distributeRoundRobin

Re-exports distributeRoundRobin

downSampleRandomly

Re-exports downSampleRandomly

escapeForRegExp

Re-exports escapeForRegExp

escapeForRegExpReplacement

Re-exports escapeForRegExpReplacement

escapeXml

Re-exports escapeXml

generateRandomString

Re-exports generateRandomString

generateRandomStringQuickly

Re-exports generateRandomStringQuickly

HttpStatusCode

Re-exports HttpStatusCode

HttpStatusMessage

Re-exports HttpStatusMessage

isInRange

Re-exports isInRange

JsonStringifyReplacer

Re-exports JsonStringifyReplacer

JsonStringifyReplacerFromPathBasedRules

Re-exports JsonStringifyReplacerFromPathBasedRules

LineLogger

Re-exports LineLogger

mask

Re-exports mask

maskAll

Re-exports maskAll

maskCreditCard

Re-exports maskCreditCard

maskEmail

Re-exports maskEmail

masker

Re-exports masker

maskFullName

Re-exports maskFullName

merge

Re-exports merge

MergeOptions

Re-exports MergeOptions

NumberUtils

Re-exports NumberUtils

pathAwareReplacer

Re-exports pathAwareReplacer

PathAwareReplacer

Re-exports PathAwareReplacer

pathBasedReplacer

Re-exports pathBasedReplacer

pluralise

Re-exports pluralise

pluralize

Re-exports pluralize

roundTo

Re-exports roundTo

shortBase64FromUInt32

Re-exports shortBase64FromUInt32

shortBase64UrlFromUInt32

Re-exports shortBase64UrlFromUInt32

snakeToCamel

Re-exports snakeToCamel

StringUtils

Re-exports StringUtils

substituteAll

Re-exports substituteAll

truncate

Re-exports truncate

unescapeXml

Re-exports unescapeXml

urlSafe

Re-exports urlSafe

Line Logger

line-logger

Classes

Class	Description
LineLogger	A LineLogger logs/prints one entire line of text before advancing to another line. This class is useful for encapsulating console.log/info/warn/error functions. By having an abstraction layer, your code can switching to a different output with nearly no change.

Type Aliases

Type Alias	Description
ConsoleLineLogger	Type of the object returned by `LineLogger.console()` or `LineLogger.consoleWithColour()`. It has the same function signatures as console.log/info/warn/error.

Variables

Variable	Description
consoleLike	Build an instance from 'log' (https://github.com/medikoo/log). `info` of the LineLogger is mapped to `notice` of the medikoo log.
consoleWithColour	Build an encapsulation of console output functions with console.log/info/warn/error and chalk/colors/cli-color.
consoleWithoutColour	Build an encapsulation of console output functions with console.log/info/warn/error.

Classes

Class: LineLogger<DEBUG_FUNC, INFO_FUNC, WARN_FUNC, ERROR_FUNC>

A LineLogger logs/prints one entire line of text before advancing to another line. This class is useful for encapsulating console.log/info/warn/error functions. By having an abstraction layer, your code can switching to a different output with nearly no change.

Please note that although the name contains "Logger", this class is not intended to be used as a generic logger. It is intended for "logging for humans to read" scenario.

LineLogger.console() and LineLogger.consoleWithColour() are ready to use convenient functions. Or you can use the constructor to build your own wrappers.

Example

// Just a wrapper of console.log/info/warn/error
const consoleLogger = LineLogger.console();

// Wrapper of console.log/info/warn/error but it mutes console.log
const lessVerboseConsoleLogger = LineLogger.console({debug: false});

// Wrapper of console.log/info/warn/error but it mutes console.log and console.info
const lessVerboseConsoleLogger = LineLogger.console({quiet: true});

// use chalk (chalk is not a dependency of this package, you need to add chalk as a dependency separately)
import chalk from 'chalk';
// this.flags is an object with properties "debug" and "quiet"
this.output = LineLogger.consoleWithColour(this.flags, chalk);
this.output.warn('Configuration file not found, default configuration would be used.');  // it would be printed out in yellow

Type Parameters

Type Parameter
`DEBUG_FUNC` extends `Function`
`INFO_FUNC` extends `Function`
`WARN_FUNC` extends `Function`
`ERROR_FUNC` extends `Function`

Constructors

Constructor

new LineLogger<DEBUG_FUNC, INFO_FUNC, WARN_FUNC, ERROR_FUNC>(debugFunction, infoFunction, warnFunction, errorFunction, isDebug, isQuiet): LineLogger<DEBUG_FUNC, INFO_FUNC, WARN_FUNC, ERROR_FUNC>

Constructor

####### Parameters

Parameter	Type	Default value	Description
`debugFunction`	`DEBUG_FUNC`	`undefined`	function for outputting debug information
`infoFunction`	`INFO_FUNC`	`undefined`	function for outputting info information
`warnFunction`	`WARN_FUNC`	`undefined`	function for outputting warn information
`errorFunction`	`ERROR_FUNC`	`undefined`	function for outputting error information
`isDebug`	`boolean`	`false`	is debug output enabled or not, it could be overriden by isQuiet
`isQuiet`	`boolean`	`false`	is quiet mode enabled or not. When quiet mode is enabled, both debug and info output would be discarded.

####### Returns

LineLogger<DEBUG_FUNC, INFO_FUNC, WARN_FUNC, ERROR_FUNC>

Properties

Property	Modifier	Type	Default value	Description
`debug`	`public`	`DEBUG_FUNC`	`undefined`	-
`error`	`public`	`ERROR_FUNC`	`undefined`	-
`info`	`public`	`INFO_FUNC`	`undefined`	-
`isDebug`	`public`	`boolean`	`false`	is debug output enabled or not, it could be overriden by isQuiet
`isQuiet`	`public`	`boolean`	`false`	is quiet mode enabled or not. When quiet mode is enabled, both debug and info output would be discarded.
`warn`	`public`	`WARN_FUNC`	`undefined`	-
`NO_OP_FUNC`	`static`	() => `void`	`undefined`	-

Methods

console()

static console<FLAGS>(flags, debugFlagName, quietFlagName): LineLogger<(message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void>

Build an instance with console.log/info/warn/error.

####### Type Parameters

Type Parameter
`FLAGS` extends `Record`<`string`, `any`>

####### Parameters

Parameter	Type	Default value	Description
`flags`	`FLAGS`	`...`	The flag object that contains fields for knowing whether debug is enabled and whether quiet mode is enabled. Values of those fields are evaluated only once within this function. They are not evaluated when debug/info/warn/error functions are called.
`debugFlagName`	keyof `FLAGS`	`'debug'`	Name of the debug field in the flags object
`quietFlagName`	keyof `FLAGS`	`'quiet'`	Name of the quiet field in the flags object

####### Returns

LineLogger<(message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void>

An instance that uses console.log/info/warn/error.

consoleLike()

static consoleLike(log): LineLogger<(message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void>

Build an instance from 'log' (https://github.com/medikoo/log). info of the LineLogger is mapped to notice of the medikoo log.

####### Parameters

Parameter	Type	Description
`log`	`MedikooLogger`	instance of the logger

####### Returns

LineLogger<(message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void>

instance of LineLogger that is actually ConsoleLineLogger type

consoleWithColour()

static consoleWithColour<FLAGS, COLOURER>(flags, colourer, debugColourFuncName, infoColourFuncName?, warnColourFuncName?, errorColourFuncName?, debugFlagName?, quietFlagName?): LineLogger<(message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void>

Build an instance with console.log/info/warn/error and chalk/colors/cli-color. This package does not depend on chalk or colors or cli-color, you need to add them as dependencies separately.

####### Type Parameters

Type Parameter
`FLAGS` extends `Record`<`string`, `any`>
`COLOURER` extends `Record`<`string`, `any`>

####### Parameters

Parameter	Type	Default value	Description
`flags`	`FLAGS`	`undefined`	The flag object that contains fields for knowning whether debug is enabled and whether quiet mode is enabled. Values of those fields are evaluated only once within this function. They are not evaluated when debug/info/warn/error functions are called.
`colourer`	`COLOURER`	`undefined`	Supplier of the colouring function, such as chalk or colors or cli-color
`debugColourFuncName`	keyof `COLOURER`	`'grey'`	Name of the function within colourer that will be used to add colour to debug messages, or null if colouring is not desired.
`infoColourFuncName?`	keyof `COLOURER`	`undefined`	Name of the function within colourer that will be used to add colour to info messages, or null if colouring is not desired.
`warnColourFuncName?`	keyof `COLOURER`	`'yellow'`	Name of the function within colourer that will be used to add colour to warn messages, or null if colouring is not desired.
`errorColourFuncName?`	keyof `COLOURER`	`'red'`	Name of the function within colourer that will be used to add colour to error messages, or null if colouring is not desired.
`debugFlagName?`	keyof `FLAGS`	`'debug'`	Name of the debug field in the flags object
`quietFlagName?`	keyof `FLAGS`	`'quiet'`	Name of the quiet field in the flags object

####### Returns

LineLogger<(message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void>

An instance that uses console.log/info/warn/error and also adds colour to the messages using chalk/colors/cli-color.

Type Aliases

Type Alias: ConsoleLineLogger

ConsoleLineLogger = ReturnType<typeof console>

Type of the object returned by LineLogger.console() or LineLogger.consoleWithColour(). It has the same function signatures as console.log/info/warn/error.

Variables

Variable: consoleLike()

const consoleLike: (log) => LineLogger<(message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void> = LineLogger.consoleLike

Build an instance from 'log' (https://github.com/medikoo/log). info of the LineLogger is mapped to notice of the medikoo log.

Parameters

Parameter	Type	Description
`log`	`MedikooLogger`	instance of the logger

Returns

LineLogger<(message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void>

instance of LineLogger that is actually ConsoleLineLogger type

Param

instance of the logger

Returns

instance of LineLogger that is actually ConsoleLineLogger type

Variable: consoleWithColour()

const consoleWithColour: <FLAGS, COLOURER>(flags, colourer, debugColourFuncName, infoColourFuncName?, warnColourFuncName, errorColourFuncName, debugFlagName, quietFlagName) => LineLogger<(message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void> = LineLogger.consoleWithColour

Build an encapsulation of console output functions with console.log/info/warn/error and chalk/colors/cli-color.

Build an instance with console.log/info/warn/error and chalk/colors/cli-color. This package does not depend on chalk or colors or cli-color, you need to add them as dependencies separately.

Type Parameters

Type Parameter
`FLAGS` extends `Record`<`string`, `any`>
`COLOURER` extends `Record`<`string`, `any`>

Parameters

Parameter	Type	Default value	Description
`flags`	`FLAGS`	`undefined`	The flag object that contains fields for knowning whether debug is enabled and whether quiet mode is enabled. Values of those fields are evaluated only once within this function. They are not evaluated when debug/info/warn/error functions are called.
`colourer`	`COLOURER`	`undefined`	Supplier of the colouring function, such as chalk or colors or cli-color
`debugColourFuncName`	keyof `COLOURER`	`'grey'`	Name of the function within colourer that will be used to add colour to debug messages, or null if colouring is not desired.
`infoColourFuncName?`	keyof `COLOURER`	`undefined`	Name of the function within colourer that will be used to add colour to info messages, or null if colouring is not desired.
`warnColourFuncName?`	keyof `COLOURER`	`'yellow'`	Name of the function within colourer that will be used to add colour to warn messages, or null if colouring is not desired.
`errorColourFuncName?`	keyof `COLOURER`	`'red'`	Name of the function within colourer that will be used to add colour to error messages, or null if colouring is not desired.
`debugFlagName?`	keyof `FLAGS`	`'debug'`	Name of the debug field in the flags object
`quietFlagName?`	keyof `FLAGS`	`'quiet'`	Name of the quiet field in the flags object

Returns

LineLogger<(message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void>

An instance that uses console.log/info/warn/error and also adds colour to the messages using chalk/colors/cli-color.

Param

The flag object that contains fields for knowning whether debug is enabled and whether quiet mode is enabled. Values of those fields are evaluated only once within this function. They are not evaluated when debug/info/warn/error functions are called.

Param

Supplier of the colouring function, such as chalk or colors or cli-color

Param

Name of the function within colourer that will be used to add colour to debug messages, or null if colouring is not desired.

Param

Name of the function within colourer that will be used to add colour to info messages, or null if colouring is not desired.

Param

Name of the function within colourer that will be used to add colour to warn messages, or null if colouring is not desired.

Param

Name of the function within colourer that will be used to add colour to error messages, or null if colouring is not desired.

Param

Name of the debug field in the flags object

Param

Name of the quiet field in the flags object. Quiet flag can override debug flag.

Returns

An LineLogger instance that uses console.log/info/warn/error and also adds colour to the messages using chalk/colors/cli-color.

Variable: consoleWithoutColour()

const consoleWithoutColour: <FLAGS>(flags, debugFlagName, quietFlagName) => LineLogger<(message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void> = LineLogger.console

Build an encapsulation of console output functions with console.log/info/warn/error.

Build an instance with console.log/info/warn/error.

Type Parameters

Type Parameter
`FLAGS` extends `Record`<`string`, `any`>

Parameters

Parameter	Type	Default value	Description
`flags`	`FLAGS`	`...`	The flag object that contains fields for knowing whether debug is enabled and whether quiet mode is enabled. Values of those fields are evaluated only once within this function. They are not evaluated when debug/info/warn/error functions are called.
`debugFlagName`	keyof `FLAGS`	`'debug'`	Name of the debug field in the flags object
`quietFlagName`	keyof `FLAGS`	`'quiet'`	Name of the quiet field in the flags object

Returns

LineLogger<(message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void, (message?, ...optionalParams) => void>

An instance that uses console.log/info/warn/error.

Param

The flag object that contains fields for knowning whether debug is enabled and whether quiet mode is enabled. Values of those fields are evaluated only once within this function. They are not evaluated when debug/info/warn/error functions are called.

Param

Name of the debug field in the flags object

Param

Name of the quiet field in the flags object. Quiet flag can override debug flag.

Returns

An LineLogger instance that uses console.log/info/warn/error.

Mask

mask

Functions

Function	Description
mask	Mask the content of a string
maskAll	Replace each character of the input with '*'
maskCreditCard	Mask credit card number string
maskEmail	Mask sensitive information in an email address while keeping some information for troubleshooting
masker	Create a mask function with pre-set parameters.
maskFullName	Mask sensitive information in the full name while keeping useful information for troubleshooting

Functions

Function: mask()

mask<T>(input, keepLeft, keepRight, minLength, maskLengthOrMaskString, maskPattern): T

Mask the content of a string

Type Parameters

Type Parameter
`T` extends `string` \| `null` \| `undefined`

Parameters

Parameter	Type	Default value	Description
`input`	`T`	`undefined`	The input which could also be null or undefined
`keepLeft`	`number`	`1`	Number of characters on the left to be kept in the output without masking. Default value is 1.
`keepRight`	`number`	`0`	Number of characters on the right to be kept in the output without masking. Default value is 0.
`minLength`	`number`	`3`	Minimal length of the string for keepLeft and keepRight to be effective. If the input string is shorter than this length, the whole string would be masked. Default value is 3.
`maskLengthOrMaskString`	`string` \| `number` \| `null` \| `undefined`	`null`	The string to be used for replacing the part in the input that needs to be masked, or the length of the mask string if a fixed length is desired, or null/undefined if the mask string should have the same length as the part to be masked. Default value is null.
`maskPattern`	`string`	`'*'`	The pattern to be repeated as the mask. Default value is '*'.

Returns

T

String with masked content

Function: maskAll()

maskAll<T>(input): T

Replace each character of the input with '*'

Type Parameters

Type Parameter
`T` extends `string` \| `null` \| `undefined`

Parameters

Parameter	Type	Description
`input`	`T`	a string or null or undefined

Returns

T

masked string or null or undefined

Function: maskCreditCard()

maskCreditCard<T>(input): T

Mask credit card number string

Type Parameters

Type Parameter
`T` extends `string` \| `null` \| `undefined`

Parameters

Parameter	Type	Description
`input`	`T`	credit card number string which could also be null or undefined

Returns

T

Something like --****-1234, or null/undefined if the input is null/undefined

Function: maskEmail()

maskEmail<T>(email): T

Mask sensitive information in an email address while keeping some information for troubleshooting

Type Parameters

Type Parameter
`T` extends `string` \| `null` \| `undefined`

Parameters

Parameter	Type	Description
`email`	`T`	the email address which could also be null or undefined

Returns

T

masked email address

Function: maskFullName()

maskFullName<T>(name): T

Mask sensitive information in the full name while keeping useful information for troubleshooting

Type Parameters

Type Parameter
`T` extends `string` \| `null` \| `undefined`

Parameters

Parameter	Type	Description
`name`	`T`	the full name which could also be null or undefined

Returns

T

masked full name

Function: masker()

masker<T>(keepLeft?, keepRight?, minLength?, maskLengthOrMaskString?, maskPattern?): (input) => T

Create a mask function with pre-set parameters.

Type Parameters

Type Parameter	Default type
`T` extends `string` \| `null` \| `undefined`	`string`

Parameters

Parameter	Type	Description
`keepLeft?`	`number`	Number of characters on the left to be kept in the output without masking. Default value is 1.
`keepRight?`	`number`	Number of characters on the right to be kept in the output without masking. Default value is 0.
`minLength?`	`number`	Minimal length of the string for keepLeft and keepRight to be effective. If the input string is shorter than this length, the whole string would be masked. Default value is 3.
`maskLengthOrMaskString?`	`string` \| `number` \| `null`	The string to be used for replacing the part in the input that needs to be masked, or the length of the mask string if a fixed length is desired, or null/undefined if the mask string should have the same length as the part to be masked. Default value is null.
`maskPattern?`	`string`	The pattern to be repeated as the mask. Default value is '*'.

Returns

A mask function that has specified parameters as pre-set

(input): T

Parameters

Parameter	Type
`input`	`T`

Returns

T

Example

const maskApiKey = masker(2, 2, 10);
  const maskedString = maskApiKey(myApiKey);

Merge

merge

Interfaces

Interface	Description
MergeOptions	Options to customize the merge behavior.

Functions

Function	Description
merge	Recursively merges properties of one or more source objects into a destination object.

Functions

Function: merge()

merge<T, U>(options, destination, ...sources): T & U[number]

Recursively merges properties of one or more source objects into a destination object.

Type Parameters

Type Parameter
`T` extends `object`
`U` extends `any`[]

Parameters

Parameter	Type	Description
`options`	`MergeOptions` \| `null` \| `undefined`	Customizes the merge behavior.
`destination`	`T`	The object to merge properties into. It will be mutated unless `options.immutable` is true.
...`sources`	`U`	The source objects.

Returns

T & U[number]

The merged object.

Interfaces

Interface: MergeOptions

Options to customize the merge behavior.

Properties

Property	Type	Description
`array?`	`"replace"` \| `"append"` \| `"merge"`	Defines how to handle arrays during the merge. - `replace`: The source array completely replaces the destination array. - `append`: The source array's elements are added to the end of the destination array. - `merge`: (Default) Mimics Lodash's behavior. It overwrites elements at the same index. If an element is an object, it merges them recursively. If the source array is longer, its additional elements are appended. Default `'merge'`
`immutable?`	`boolean`	If `true`, the merge will be immutable, creating a new object. If `false` or not provided, the destination object will be mutated. Default `false`
`set?`	`"replace"` \| `"merge"`	Defines how to handle `Set` objects during the merge. - `replace`: (Default) The source `Set` completely replaces the destination `Set`. - `merge`: A new `Set` is created containing all elements from both the destination and source `Set`s. Default `'replace'`

Number

number

Classes

Class	Description
NumberUtils	-

Variables

Variable	Description
clamp	Constrains a number within specified bounds.
isInRange	Checks if a number is within a specified range (inclusive).
roundTo	Rounds a number to a specified number of decimal places.

Classes

Class: NumberUtils

Constructors

Constructor

new NumberUtils(): NumberUtils

####### Returns

NumberUtils

Methods

clamp()

static clamp(num, min, max): number

Constrains a number within specified bounds.

####### Parameters

Parameter	Type	Description
`num`	`number`	The number to clamp
`min`	`number`	The minimum value
`max`	`number`	The maximum value

####### Returns

number

The clamped value

isInRange()

static isInRange(num, min, max): boolean

Checks if a number is within a specified range (inclusive).

####### Parameters

Parameter	Type	Description
`num`	`number`	The number to check
`min`	`number`	The minimum value
`max`	`number`	The maximum value

####### Returns

boolean

True if the number is within range

roundTo()

static roundTo(num, precision): number

Rounds a number to a specified number of decimal places.

####### Parameters

Parameter	Type	Default value	Description
`num`	`number`	`undefined`	The number to round
`precision`	`number`	`0`	The number of decimal places (default: 0)

####### Returns

number

Rounded number

Variables

Variable: clamp()

const clamp: (num, min, max) => number = NumberUtils.clamp

Constrains a number within specified bounds.

Parameters

Parameter	Type	Description
`num`	`number`	The number to clamp
`min`	`number`	The minimum value
`max`	`number`	The maximum value

Returns

number

The clamped value

Param

The number to clamp

Param

The minimum value

Param

The maximum value

Returns

The clamped value

Variable: isInRange()

const isInRange: (num, min, max) => boolean = NumberUtils.isInRange

Checks if a number is within a specified range (inclusive).

Parameters

Parameter	Type	Description
`num`	`number`	The number to check
`min`	`number`	The minimum value
`max`	`number`	The maximum value

Returns

boolean

True if the number is within range

Param

The number to check

Param

The minimum value

Param

The maximum value

Returns

True if the number is within range

Variable: roundTo()

const roundTo: (num, precision) => number = NumberUtils.roundTo

Rounds a number to a specified number of decimal places.

Parameters

Parameter	Type	Default value	Description
`num`	`number`	`undefined`	The number to round
`precision`	`number`	`0`	The number of decimal places (default: 0)

Returns

number

Rounded number

Param

The number to round

Param

The number of decimal places (default: 0)

Returns

Rounded number

String

string

Classes

Class	Description
StringUtils	-

Variables

Variable	Description
applyWordCasing	Preserve basic casing from a template single word and apply it to another word.
camelToSnake	Converts a camelCase string to snake_case.
capitalise	Capitalises the first letter of a string, making the rest lowercase.
capitalize	Capitalizes the first letter of a string, making the rest lowercase.
escapeXml	Escapes special XML entities/characters in a string. Replaces &, <, >, ", and ' with their corresponding XML entities. Designed for performance using a single pass and lookup table.
pluralise	Returns the plural form of a single English word based on the supplied count (alias).
pluralize	Returns the plural form of a single English word based on the supplied count.
snakeToCamel	Converts a snake_case string to camelCase.
truncate	Truncates a string to a specified length, optionally adding a suffix.
unescapeXml	Unescapes XML entities/characters in a string. Converts &, <, >, ", ' back to their original characters.

Classes

Class: StringUtils

Constructors

Constructor

new StringUtils(): StringUtils

####### Returns

StringUtils

Methods

applyWordCasing()

static applyWordCasing(casingTemplate, word): string

Preserve basic casing from a template single word and apply it to another word.

Rules:

If casingTemplate is all upper-case, return word in all upper-case.
If casingTemplate is Title Case (first letter uppercase, rest lowercase), return word in Title Case.
Otherwise return word as-is.

This helper focuses on single-word tokens only and intentionally does not handle complex multi-word or mixed-case patterns. Use for word-level casing preservation (for example, to preserve input casing when returning a pluralized form).

####### Parameters

Parameter	Type	Description
`casingTemplate`	`string`	A word whose casing should be copied (e.g. 'Cat' or 'CAT')
`word`	`string`	The word to apply casing to (usually a transformed/lowercased form)

####### Returns

string

The word adjusted to match the template's basic casing

camelToSnake()

static camelToSnake(str): string

Converts a camelCase string to snake_case.

####### Parameters

Parameter	Type	Description
`str`	`string`	The camelCase string to convert

####### Returns

string

snake_case string

capitalise()

static capitalise(str): string

Capitalises the first letter of a string, making the rest lowercase.

####### Parameters

Parameter	Type	Description
`str`	`string`	The string to capitalise

####### Returns

string

Capitalised string

capitalize()

static capitalize(str): string

Capitalizes the first letter of a string, making the rest lowercase.

####### Parameters

Parameter	Type	Description
`str`	`string`	The string to capitalize

####### Returns

string

Capitalized string

escapeXml()

static escapeXml<T>(str): T

Escapes special XML entities/characters in a string. Replaces &, <, >, ", and ' with their corresponding XML entities. Designed for performance using a single pass and lookup table.

####### Type Parameters

Type Parameter
`T` extends `string` \| `null` \| `undefined`

####### Parameters

Parameter	Type	Description
`str`	`T`	The string to escape for XML

####### Returns

T

The escaped XML string

pluralise()

static pluralise(word, count): string

Returns the plural form of a single English word based on the supplied count.

Capabilities:

Preserves basic input casing (using applyWordCasing) so e.g. "Cat" -> "Cats", "CAT" -> "CATS".
Handles common irregular plurals (person->people, child->children, mouse->mice, etc.).
Treats a number of nouns as uncountable (sheep, fish, species, series, news, etc.).
Applies common rules: f/fe -> ves (knife->knives), consonant+y -> ies (baby->babies), words ending with s/x/z/ch/sh -> add 'es'.
For words ending with 'o' there is a small exceptions list that will add 'es' (hero, potato, tomato, echo, torpedo); otherwise 's' is added.

Limitations and notes:

This is a pragmatic, rule-based implementation covering the most common English cases, not a complete linguistic solution. It does not support locales or full irregular/exception lists (many English words have irregular forms not included here).
The function expects a single word token. It does not pluralize multi-word phrases or attempt to inflect verbs. Use a dedicated library (for example, the 'pluralize' npm package) if you need comprehensive, production-grade pluralization.
Casing preservation is basic (all-caps and Title Case); mixed/mid-word casing (camelCase, acronyms inside words) is not fully reconstructed.

####### Parameters

Parameter	Type	Description
`word`	`string`	The single English word to pluralize (may be mixed case)
`count`	`number`	The numeric count; if equal to 1 the original word is returned

####### Returns

string

The pluralized word with basic casing preserved

pluralize()

static pluralize(word, count): string

Returns the plural form of a single English word based on the supplied count.

Capabilities:

Preserves basic input casing (using applyWordCasing) so e.g. "Cat" -> "Cats", "CAT" -> "CATS".
Handles common irregular plurals (person->people, child->children, mouse->mice, etc.).
Treats a number of nouns as uncountable (sheep, fish, species, series, news, etc.).
Applies common rules: f/fe -> ves (knife->knives), consonant+y -> ies (baby->babies), words ending with s/x/z/ch/sh -> add 'es'.
For words ending with 'o' there is a small exceptions list that will add 'es' (hero, potato, tomato, echo, torpedo); otherwise 's' is added.

Limitations and notes:

This is a pragmatic, rule-based implementation covering the most common English cases, not a complete linguistic solution. It does not support locales or full irregular/exception lists (many English words have irregular forms not included here).
The function expects a single word token. It does not pluralize multi-word phrases or attempt to inflect verbs. Use a dedicated library (for example, the 'pluralize' npm package) if you need comprehensive, production-grade pluralization.
Casing preservation is basic (all-caps and Title Case); mixed/mid-word casing (camelCase, acronyms inside words) is not fully reconstructed.

####### Parameters

Parameter	Type	Description
`word`	`string`	The single English word to pluralize (may be mixed case)
`count`	`number`	The numeric count; if equal to 1 the original word is returned

####### Returns

string

The pluralized word with basic casing preserved

snakeToCamel()

static snakeToCamel(str): string

Converts a snake_case string to camelCase.

####### Parameters

Parameter	Type	Description
`str`	`string`	The snake_case string to convert

####### Returns

string

camelCase string

truncate()

static truncate(str, length, suffix): string

Truncates a string to a specified length, optionally adding a suffix.

####### Parameters

Parameter	Type	Default value	Description
`str`	`string`	`undefined`	The string to truncate
`length`	`number`	`undefined`	Maximum length of the resulting string (including suffix if provided)
`suffix`	`string`	`'...'`	Optional suffix to add to truncated string (default: '...')

####### Returns

string

Truncated string

unescapeXml()

static unescapeXml<T>(str): T

Unescapes XML entities/characters in a string. Converts &, <, >, ", ' back to their original characters.

####### Type Parameters

Type Parameter
`T` extends `string` \| `null` \| `undefined`

####### Parameters

Parameter	Type	Description
`str`	`T`	The string to unescape from XML

####### Returns

T

The unescaped string

Variables

Variable: applyWordCasing()

const applyWordCasing: (casingTemplate, word) => string = StringUtils.applyWordCasing

Preserve basic casing from a template single word and apply it to another word.

Rules:

If casingTemplate is all upper-case, return word in all upper-case.
If casingTemplate is Title Case (first letter uppercase, rest lowercase), return word in Title Case.
Otherwise return word as-is.

This helper focuses on single-word tokens only and intentionally does not handle complex multi-word or mixed-case patterns. Use for word-level casing preservation (for example, to preserve input casing when returning a pluralized form).

Preserve basic casing from a template single word and apply it to another word.

Rules:

If casingTemplate is all upper-case, return word in all upper-case.
If casingTemplate is Title Case (first letter uppercase, rest lowercase), return word in Title Case.
Otherwise return word as-is.

This helper focuses on single-word tokens only and intentionally does not handle complex multi-word or mixed-case patterns. Use for word-level casing preservation (for example, to preserve input casing when returning a pluralized form).

Parameters

Parameter	Type	Description
`casingTemplate`	`string`	A word whose casing should be copied (e.g. 'Cat' or 'CAT')
`word`	`string`	The word to apply casing to (usually a transformed/lowercased form)

Returns

string

The word adjusted to match the template's basic casing

Param

A word whose casing should be copied (e.g. 'Cat' or 'CAT')

Param

The word to apply casing to (usually a transformed/lowercased form)

Returns

The word adjusted to match the template's basic casing

Variable: camelToSnake()

const camelToSnake: (str) => string = StringUtils.camelToSnake

Converts a camelCase string to snake_case.

Parameters

Parameter	Type	Description
`str`	`string`	The camelCase string to convert

Returns

string

snake_case string

Param

The camelCase string to convert

Returns

snake_case string

Variable: capitalise()

const capitalise: (str) => string = StringUtils.capitalise

Capitalises the first letter of a string, making the rest lowercase.

Parameters

Parameter	Type	Description
`str`	`string`	The string to capitalise

Returns

string

Capitalised string

Param

The string to capitalise

Returns

Capitalised string

Variable: capitalize()

const capitalize: (str) => string = StringUtils.capitalize

Capitalizes the first letter of a string, making the rest lowercase.

Parameters

Parameter	Type	Description
`str`	`string`	The string to capitalize

Returns

string

Capitalized string

Param

The string to capitalize

Returns

Capitalized string

Variable: escapeXml()

const escapeXml: <T>(str) => T = StringUtils.escapeXml

Escapes special XML entities/characters in a string. Replaces &, <, >, ", and ' with their corresponding XML entities. Designed for performance using a single pass and lookup table.

Type Parameters

Type Parameter
`T` extends `string` \| `null` \| `undefined`

Parameters

Parameter	Type	Description
`str`	`T`	The string to escape for XML

Returns

T

The escaped XML string

Param

The string to escape for XML

Returns

The escaped XML string

Variable: pluralise()

const pluralise: (word, count) => string = StringUtils.pluralise

Returns the plural form of a single English word based on the supplied count (alias).

See pluralize for capabilities and limitations.

Returns the plural form of a single English word based on the supplied count.

Capabilities:

Preserves basic input casing (using applyWordCasing) so e.g. "Cat" -> "Cats", "CAT" -> "CATS".
Handles common irregular plurals (person->people, child->children, mouse->mice, etc.).
Treats a number of nouns as uncountable (sheep, fish, species, series, news, etc.).
Applies common rules: f/fe -> ves (knife->knives), consonant+y -> ies (baby->babies), words ending with s/x/z/ch/sh -> add 'es'.
For words ending with 'o' there is a small exceptions list that will add 'es' (hero, potato, tomato, echo, torpedo); otherwise 's' is added.

Limitations and notes:

This is a pragmatic, rule-based implementation covering the most common English cases, not a complete linguistic solution. It does not support locales or full irregular/exception lists (many English words have irregular forms not included here).
The function expects a single word token. It does not pluralize multi-word phrases or attempt to inflect verbs. Use a dedicated library (for example, the 'pluralize' npm package) if you need comprehensive, production-grade pluralization.
Casing preservation is basic (all-caps and Title Case); mixed/mid-word casing (camelCase, acronyms inside words) is not fully reconstructed.

Parameters

Parameter	Type	Description
`word`	`string`	The single English word to pluralize (may be mixed case)
`count`	`number`	The numeric count; if equal to 1 the original word is returned

Returns

string

The pluralized word with basic casing preserved

Param

The single English word to pluralize (may be mixed case)

Param

The numeric count; if equal to 1 the original word is returned

Returns

The pluralized word with basic casing preserved

Variable: pluralize()

const pluralize: (word, count) => string = StringUtils.pluralize

Returns the plural form of a single English word based on the supplied count.

Capabilities:

Preserves basic input casing (using applyWordCasing) so e.g. "Cat" -> "Cats", "CAT" -> "CATS".
Handles common irregular plurals (person->people, child->children, mouse->mice, etc.).
Treats a number of nouns as uncountable (sheep, fish, species, series, news, etc.).
Applies common rules: f/fe -> ves (knife->knives), consonant+y -> ies (baby->babies), words ending with s/x/z/ch/sh -> add 'es'.
For words ending with 'o' there is a small exceptions list that will add 'es' (hero, potato, tomato, echo, torpedo); otherwise 's' is added.

Limitations and notes:

This is a pragmatic, rule-based implementation covering the most common English cases, not a complete linguistic solution. It does not support locales or full irregular/exception lists (many English words have irregular forms not included here).
The function expects a single word token. It does not pluralize multi-word phrases or attempt to inflect verbs. Use a dedicated library (for example, the 'pluralize' npm package) if you need comprehensive, production-grade pluralization.
Casing preservation is basic (all-caps and Title Case); mixed/mid-word casing (camelCase, acronyms inside words) is not fully reconstructed.

Returns the plural form of a single English word based on the supplied count.

Capabilities:

Preserves basic input casing (using applyWordCasing) so e.g. "Cat" -> "Cats", "CAT" -> "CATS".
Handles common irregular plurals (person->people, child->children, mouse->mice, etc.).
Treats a number of nouns as uncountable (sheep, fish, species, series, news, etc.).
Applies common rules: f/fe -> ves (knife->knives), consonant+y -> ies (baby->babies), words ending with s/x/z/ch/sh -> add 'es'.
For words ending with 'o' there is a small exceptions list that will add 'es' (hero, potato, tomato, echo, torpedo); otherwise 's' is added.

Limitations and notes:

This is a pragmatic, rule-based implementation covering the most common English cases, not a complete linguistic solution. It does not support locales or full irregular/exception lists (many English words have irregular forms not included here).
The function expects a single word token. It does not pluralize multi-word phrases or attempt to inflect verbs. Use a dedicated library (for example, the 'pluralize' npm package) if you need comprehensive, production-grade pluralization.
Casing preservation is basic (all-caps and Title Case); mixed/mid-word casing (camelCase, acronyms inside words) is not fully reconstructed.

Parameters

Parameter	Type	Description
`word`	`string`	The single English word to pluralize (may be mixed case)
`count`	`number`	The numeric count; if equal to 1 the original word is returned

Returns

string

The pluralized word with basic casing preserved

Param

The single English word to pluralize (may be mixed case)

Param

The numeric count; if equal to 1 the original word is returned

Returns

The pluralized word with basic casing preserved

Variable: snakeToCamel()

const snakeToCamel: (str) => string = StringUtils.snakeToCamel

Converts a snake_case string to camelCase.

Parameters

Parameter	Type	Description
`str`	`string`	The snake_case string to convert

Returns

string

camelCase string

Param

The snake_case string to convert

Returns

camelCase string

Variable: truncate()

const truncate: (str, length, suffix) => string = StringUtils.truncate

Truncates a string to a specified length, optionally adding a suffix.

Parameters

Parameter	Type	Default value	Description
`str`	`string`	`undefined`	The string to truncate
`length`	`number`	`undefined`	Maximum length of the resulting string (including suffix if provided)
`suffix`	`string`	`'...'`	Optional suffix to add to truncated string (default: '...')

Returns

string

Truncated string

Param

The string to truncate

Param

Maximum length of the resulting string (including suffix if provided)

Param

Optional suffix to add to truncated string (default: '...')

Returns

Truncated string

Variable: unescapeXml()

const unescapeXml: <T>(str) => T = StringUtils.unescapeXml

Unescapes XML entities/characters in a string. Converts &, <, >, ", ' back to their original characters.

Type Parameters

Type Parameter
`T` extends `string` \| `null` \| `undefined`

Parameters

Parameter	Type	Description
`str`	`T`	The string to unescape from XML

Returns

T

The unescaped string

Param

The string to unescape from XML

Returns

The unescaped string

Stringify Replacer

stringify-replacer

Type Aliases

Type Alias	Description
JsonStringifyReplacer	The original replacer expected by JSON.stringify(...)
JsonStringifyReplacerFromPathBasedRules	A JsonStringifyReplacer that was created from path based rules. Those rules are stored in the `rules` property in case of need.
PathAwareReplacer	The replacer that can potentially utilise the full path of the property in the object.

Functions

Function	Description
pathAwareReplacer	Build a replacer function that can be passed to JSON.stringify(...).
pathBasedReplacer	Create a replacer function for JSON.stringify(...) from an array of path based rules. This function is useful for creating masking replacers which can apply masking based on the path of the property.

Functions

Function: pathAwareReplacer()

pathAwareReplacer(replacer, options?): JsonStringifyReplacer

Build a replacer function that can be passed to JSON.stringify(...).

Parameters

Parameter	Type	Description
`replacer`	`PathAwareReplacer`	The actual replacer function which could utilise additional information.
`options?`	{ `ancestors?`: `boolean`; `pathArray?`: `boolean`; }	Options to control whether the pathArray and ancestors parameters would have values populated. By default all information available would be populated. There is no need to specify options unless you are extremely concerned about performance, for example if you need to frequently stringify 500MB objects.
`options.ancestors?`	`boolean`	When false, ancestors would be an empty array.
`options.pathArray?`	`boolean`	When false, pathArray would be an empty array. This would remove the need to construct a pathArray from the path string.

Returns

JsonStringifyReplacer

The replacer function that can be passed to JSON.stringify(...).

Function: pathBasedReplacer()

pathBasedReplacer(rules): JsonStringifyReplacerFromPathBasedRules

Create a replacer function for JSON.stringify(...) from an array of path based rules. This function is useful for creating masking replacers which can apply masking based on the path of the property.

Parameters

Parameter	Type	Description
`rules`	[`RegExp`, (`input`) => `any`][]	Array of rules: if the regular expression tests true with the property path, the replacer function will be applied on the value

Returns

JsonStringifyReplacerFromPathBasedRules

The replacer function built from those path based rules. It also has a rules property storing all the path based rules provided as inputs.

Example

import { mask, maskAll, maskEmail, maskFullName, pathBasedReplacer } from '@handy-common-utils/misc-utils';
console.log(JSON.stringify(obj, pathBasedReplacer([
 [/.*\.x-api-key$/, maskAll],
 [/.*customer\.name$/, maskFullName],
 [/.*customer\..*[eE]mail$/, maskEmail],
 [/.*\.zip$/, (value: string) => value.slice(0, 3) + 'XX'],
 [/.*\.cc$/, () => undefined],
 [/.*\.ssn$/, mask],
])));

Type Aliases

Type Alias: JsonStringifyReplacer()

JsonStringifyReplacer = (this, key, value) => any

The original replacer expected by JSON.stringify(...)

Parameters

Parameter	Type
`this`	`any`
`key`	`string`
`value`	`any`

Returns

any

Type Alias: JsonStringifyReplacerFromPathBasedRules

JsonStringifyReplacerFromPathBasedRules = JsonStringifyReplacer & object

A JsonStringifyReplacer that was created from path based rules. Those rules are stored in the rules property in case of need.

Type Declaration

Name	Type
`rules`	[`RegExp`, (`input`) => `any`][]

Type Alias: PathAwareReplacer()

PathAwareReplacer = (key, value, path, parent, pathArray, ancestors) => any

The replacer that can potentially utilise the full path of the property in the object.

Parameters

Parameter	Type	Description
`key`	`string`	Name of the property, or the index in the parent array.
`value`	`any`	Value of the property or the object in the parent array.
`path`	`string`	The full path of the property in the object, such like "access.visitor.location" or "request.x-forwarded-for.0". Please note that the special characters (including ".") in property names are not escaped, for example, "order.billing address.first line".
`parent`	`Parent`	The object that the property or the element belongs to. It could be `{ '': <the original object> }` when this replacer function is called the first time.
`pathArray`	`string`[]	The full path as an array. It is more useful than `path` in case special characters exist in property names. When this replacer function is called the first time, pathArray array would have a zero length.
`ancestors`	`Parent`[]	All the ancestor objects/arrays of the property. When this replacer function is called the first time, ancestors array would have a zero length.

Returns

any

Substitute

substitute

Functions

Function	Description
substituteAll	Substitute all occurrences of a pattern in a string.

Functions

Function: substituteAll()

substituteAll<T>(input, searchPattern, substitute): T

Substitute all occurrences of a pattern in a string.

Type Parameters

Type Parameter
`T` extends `string` \| `null` \| `undefined`

Parameters

Parameter	Type	Description
`input`	`T`	The input string on which the substitutions will be performed.
`searchPattern`	`RegExp`	The regular expression pattern used to search for segments that should be substituted. It must have the `g` flag set. If the beginning part of the `input` should be skipped, set the `lastIndex` of the `searchPattern` before calling this function. After all the substitution are done, the `lastIndex` of the `searchPattern` will be reset to zero. See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/lastIndex
`substitute`	(`match`, `matchResult`) => `string` \| `null`	TThe function that builds the substitution string. It is called with the matched substring and the result of `RegExp.exec()`. See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/exec#examples. The function can return null to indicate that no further substitution is desired. In such case, the `lastIndex` of the `searchPattern` will not be reset to zero.

Returns

T

The resulting string after performing all substitutions.

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src		src
test		test
.escheckrc		.escheckrc
.gitignore		.gitignore
.mocharc.yml		.mocharc.yml
.nvmrc		.nvmrc
.nycrc.yml		.nycrc.yml
.releaserc.json		.releaserc.json
LICENSE		LICENSE
README.md		README.md
eslint.config.cjs		eslint.config.cjs
package-lock.json		package-lock.json
package.json		package.json
tsconfig.json		tsconfig.json
tsconfig.test.json		tsconfig.test.json

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handy-common-utils/misc-utils

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@handy-common-utils/misc-utils

Features

Installation

Quick Examples

Array Utilities

Encoding of Strings

Error Classification

Line Logger

String Masking

JSON Stringify with Replacers

String Substitution

String Utilities

Number Utilities

Masking

Replacers for JSON.stringify(input, replacer, space)

substituteAll

Example Usage Scenarios:

API

@handy-common-utils/misc-utils

Modules

Array

array

Functions

Functions

Function: distributeRoundRobin()

Type Parameters

Parameters

Returns

Function: downSampleRandomly()

Type Parameters

Parameters

Returns

Codec

codec

Functions

Functions

Function: base64FromUInt32()

Type Parameters

Parameters

Returns

Function: base64UrlFromUInt32()

Type Parameters

Parameters

Returns

Function: escapeForRegExp()

Parameters

Returns

Function: escapeForRegExpReplacement()

Parameters

Returns

Function: generateRandomString()

Parameters

Returns

Function: generateRandomStringQuickly()

Parameters

Returns

Function: shortBase64FromUInt32()

Type Parameters

Parameters

Returns

Function: shortBase64UrlFromUInt32()

Type Parameters

Parameters

Returns

Function: urlSafe()

Type Parameters

Parameters

Returns

Errors

errors

Functions

Functions

Function: couldBeNetworkingTimeoutError()

Parameters