Rolling TS Utils

A small library which exposes some helpful generic utility types. This is an early version and currently contains only a few types, but will be gradually expanded and improved.

Installation

npm install --save-dev rolling-ts-utils

Basic Usage

import type { ReplaceStringPart } from "rolling-ts-utils";

const str = "This is a cool {noun}." as const;

let sentence: ReplaceStringPart<typeof str, "dog">;
//  ^? typeof sentence = "This is a cool dog."

Available Types

ReplaceStringPart<OriginalString, NewString>

• OriginalString: The string to be replaced
• NewString: The string to replace the first occurrence of {string}, where string is any string
• If no {string} is found, the original string is returned

const str = "This is a cool {noun}." as const;

let sentence: ReplaceStringPart<typeof str, "dog">;
//  ^? typeof sentence = "This is a cool dog."

ReplaceStringPart<OriginalString, NewString, Match>

• OriginalString: The string to be replaced
• NewString: The string to be inserted at the first occurance of Match
• Match: The substring to be replaced
• If no match is found, the original string is returned

const str = "This is a cool {noun}." as const;

let sentence: ReplaceStringPart<typeof str, "cat", "{noun}">;
//  ^? typeof sentence = "This is a cool cat."

ReplaceStringPartGlobal<OriginalString, NewString, Match>

• OriginalString: The string to be replaced
• NewString: The string to be inserted at each occurance of Match
• Match: The substring to be replaced
• If no match is found, the original string is returned

const str = "This is {word} {word} {thing}." as const;

let sentence: ReplaceStringPartGlobal<typeof str, "dog", "{word}">;
//  ^? typeof sentence = "This is dog dog {thing}."

ReplaceOrderedStringParts<OriginalString, NewStrings, Index>

• OriginalString: The string to be replaced
• NewStrings: An array of strings to be inserted in order
• Index: The index of the substring to be replaced (this should normally be left empty)
• If no {string} is found, the original string is returned

This will break if the NewStrings array contains more than 1000 elements

const str = "This is {article} {adjective} {noun}." as const;

let sentence: ReplaceOrderedStringParts<
  typeof str,
  ["an", "amazing", "rabbit"]
>;
//  ^? typeof sentence = "This is an amazing rabbit."

ReplaceMultipleStringParts<OriginalString, Keys, Values, Index>

• OriginalString: The string to be replaced
• Keys: An array of substrings to be replaced
• Values: An array of strings to be inserted in place of the key at the same position in the Keys array
• Index: The index of the substring to be replaced (this should normally be left empty)
• If no match is found, the key-value pair has no impact

This will break if the Keys array contains more than 1000 elements

const str = "This is {article} {adjective} {noun}." as const;

let sentence: ReplaceMultipleStringParts<
  typeof str,
  ["{article}", "{adjective}", "{noun}"],
  ["an", "interesting", "duck"]
>;
//  ^? typeof sentence = "This is an interesting duck."

ReplaceAllStringParts<OriginalString, NewString>

• OriginalString: The string to be replaced
• NewString: The string to be inserted in place of ALL occurrences of {string}, where string is any string

const str = "This is {article} {adjective} {noun}." as const;

let sentence: ReplaceAllStringParts<typeof str, "dog">;
//  ^? typeof sentence = "This is dog dog dog."

Inc<OriginalNum>

• OriginalNum: A number to be incremented

This will break if OriginalNum is greater than 999

type OriginalNum = 5;

type IncrementedNum = Inc<OriginalNum>;
//   ^? type IncrementedNum = 6