_f

Moxy String, Array, and Object library for TypeScript / NodeJS. Array functions are immutable by default, providing you with copies rather than references.

Installation

npm i underscore-functions

Usage

const _f = require('underscore-functions')

String Functions

• pascalCase = (s: string): string => Converts to Pascal Case
• camelCase = (s: string): string => Converts to camel case
• nl2br = (s: string) => Converts new lines to break tags
• br2nl = (s: string) => Converts break tags to new lines
• splitByLength = (s: string, len: number) => Splits a string by length
• upperCaseWords = (s: string) => Upper cases words in a string
• upperCaseFirst = (s: string) => Upper cases the first letter of a string.
• upperCaseFirstInSentence = (s: string) => Upper cases the first letter in each sentence.
• decodeHTML = (html: string): string => decodes HTML into safe characters
• toAlpha = (s: string, charSet?: string) => Converts to alpha-only characters
• toNumeric = (s: string, charSet?: string) => Converts to number-only characters
• toBinary = (s: string) => Converts to binary
• fromBinary = (s: string) => Converts from binary
• toHex = (s: string) => Converts to Hex
• fromHex = (s: string) => Converts from Hex
• toBase64 = (s: string) => Converts to Base64
• fromBase64 = (s: string) => Converts from Base64
• rightRotate = (s: string, bits: number) => Right rotates a string
• leftRotate = (s: string, bits: number) => Left rotates a string
• rightShift = (s: string, bits: number, char: string = '0') => Right shifts a string
• reverse = (s: string) => Reverses a string
• reverseWords = (s: string) => Reverses words in a string
• shuffle = (a: string | any[]) => Shuffle a string
• keyToField = (s: string, strip?: string) => Converts a key to a human readable field
• isAlpha = (s: string, ignoreChars?: string) => Returns true if the string contains only alpha characters, with an optional set of characters to ignore
• isNumeric = (s: string, ignoreChars?: string) => Returns true if the string contains only numeric characters, with an optional set of characters to ignore
• isAlphaNumeric = (s: string, ignoreChars?: string) => Returns true if the string contains only alpha numeric characters, with an optional set of characters to ignore
• uniqueId = (prefix?: string, postfix?: string) => Generates a unique ID
• firstUniqueCharacter = (s: string) => Returns the first non-repeating character in a string
• randomString = (len: number, charSet?: string) => Generates a random string of N length using an optionally defined character set.
• isShouting = (s: string, optionalThreshold?: number) => Returns true if a sentence (more than 5 characters long) is detected as being SHOUTED OUT. Threshold is the fractional percentage of uppercase text.
• getRepeatingCharacters = (s: string, ignoreCase?: boolean, minRepeat: number = 2) => Get all repeating characters in a string
• hasRepeatingCharacters = (s: string, ignoreCase?: boolean, minRepeat: number = 2) => Returns true if a string has repeating characters, booo = 2 repeated 'o' characters.
• getRepeatingSets = (s: string, ignoreCase?: boolean, minRepeat: number = 2) => Get all repeating sets in a string
• hasRepeatingSets = (s: string, ignoreCase?: boolean, minRepeat: number = 2) => Returns true if a string has repeating sets, hellohellohello = 2 repeated 'hello' sets.
• getSequences = (s: string, ignoreCase?: boolean) => Returns all sequences (eg. 123, abc, 321) in a string
• hasSequences = (s: string, ignoreCase?: boolean) => Returns true if a string has characters or numbers in sequence or reverse sequence (eg. 123, abc, 321)
• levenshtein = (s: string, s2: string) => Returns the number of edits (deletes/inserts/substitutions) required to get from string s to string s2.
• justifyText = (text: string, len: number = 20) => Returns justified text broken into lines of n size.
• isJson = (s: string) => Returns true if string is valid JSON
• stringifyCache = (o: any, _returnTemplate: boolean = false): TStringifyCacheResult => Caches the object schema and returns a stringify function that is twice as fast as native JSON.stringify (on average)
• stringifyT = (o: any, tpl: string = '') => Returns a string representation of an object. This is the same function that is returned by stringifyCache. Use in combination with the _returnTemplate parameter of stringifyCache to cache known object schemas and stringify them later.
• stripTags = (s: string) => Returns a string with <tags> (presumably HTML) omitted.

Object Functions

• deepFreeze = (a: any) => Make an object and all nested objects immutable
• leftJoin = (a: any, b: any[], criteria?: () => boolean) => Left join an array of JSON documents onto a source
• rightJoin = (a: any, b: any[], criteria?: () => boolean) => Right join an array of JSON documents onto a source

Array Functions

• compact = (a: any[]) => Removes values that are falsey
• first = (a: any[], byRef: boolean = false) => Returns the first element in an array (as a copy by default)
• last = (a: any[], byRef: boolean = false) => Returns the last element in an array (as a copy by default)
• findFirst = (a: any[], cond: (item: any) => boolean, byRef: boolean = false) => Returns the first element in an array (as a copy by default) that matches a condition
• findLast = (a: any[], cond: (item: any) => boolean, byRef: boolean = false) => Returns the last element in an array (as a copy by default) that matches a condition
• unique = (a: any[]) => Returns only the unique values in an array
• uniqueBy = (a: any[], prop: string, byRef: boolean = false) => Returns only the unique values in an array by a specific property. Returns a new copy by default
• deepClone = (a: any) => Deep clone an object or array so that is is a pure copy
• flat = (a: any) => Flatten an array
• shuffle = (a: string | any[]) => Shuffle an array
• range = (start: number, end?: number, step?: number) => Creates a range of numbers
• lrange = (start: number, end?: number, step?: number) => Generates a number within a range as you iterate through. Useful for large ranges of values
• partition = (a: any[], size: number) => Partitions an array into segments of X size

Number Functions

• secureRandomNumber = (min: number, max: number) => Generates a cryptographically secure number using the crypto NodeJS package.
• round = (n: number, precision: number = 0.5, ERoundOption = { ROUND: 0, ROUND_UP: 1, ROUND_DOWN: 2 } ) => Round to the nearest X number.
• add = (...n: number[]) => Adds numbers together with precision up to 15 decimal places. Works around the floating point issue (0.2 + 0.1 = 0.30000000000000004, should be 0.3)
• subtract = (...n: number[]) => Subtracts numbers with precision up to 15 decimal places
• multiply = (...n: number[]) => Multiply numbers with precision up to 15 decimal places. Works around the floating point issue (0.2 * 0.1 = 0.020000000000000004, should be 0.02)
• divide = (...n: number[]) => Divide numbers with precision up to 15 decimal places
• intToRoman = (num: number) => Converts numbers less than 4,000,000 to roman numeral, (eg: 7 = VII)

Date Functions

• unixTimestamp = () => Returns the time in milliseconds since the Unix epoch (00:00:00 UTC on 1 January 1970)

Misc Functions

• check = (value: any, type: any, throwErr: boolean = true) => Returns true if the value's type matches the type passed. Otherwise throws an error or returns false depending on the optional 3rd parameter.
• memoize = (n: number)(fn: (...args: any) => any) => Caches n results of the callback function passed into it. eg: _f.memoize(5)(callbackFn) will store the most recently used results based on the included arguments. Highly efficient for recursive algorithms where you don't want to recalculate explored states/paths. Argument checks are done by value (not by reference). This algorithm performs better than memoizerific by a factor of 10 in some cases (for example, when reaching the cache limit)
• sanitize = (stringOrObject: any, mode: ESanitize = ESanitize.MONGO) => Returns a sanitized string or object based on mode, (MONGO = 1, SQL = 2, HTML = 3). MONGO removes queries from JSON objects (eg: keys that start with $). SQL escapes (adds backslashes to) unsafe characters. HTML converts special characters into printable entities, (eg: '<' becomes '&lt;').
• safeEval = async (s: string, context?: any = {}, timeout?: number = 5000): Promise => Evaluates stringified code in a sandboxed environment. Supports both NodeJS and browser environments. safeEval does not mutate context, it returns a copy of the context with mutations based on the evaluated code. This function runs async and resolves with a Promise.
• simpleEval = (s: string) => Evaluates stringified code using a Function wrapper instead of eval() as recommended by Mozilla. Use safeEval if security is a top priority.

Usage

const _f = require('underscore-functions')
const str = _f.upperCaseWords('hello world') // Hello World

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