text-align

A utility for aligning mixed English and CJK (Chinese, Japanese, Korean) text by adding appropriate padding spaces based on character display width.

Features

• Supports mixed English and CJK text alignment
• Handles various CJK character ranges including:
  • Chinese (Hanzi)
  • Japanese (Hiragana, Katakana)
  • Korean (Hangul)
  • Full-width characters
• Customizable character width rules
• Customizable placeholder character
• Zero dependencies
• TypeScript support

Installation

npm install text-aligner

Usage

import {alignText} from 'text-aligner'

const strings = ['Hello 你好', 'Hi 早上好', 'Good morning 晚安']

const aligned = alignText(strings)
console.log(aligned)
// [
//   'Hello 你好       ',
//   'Hi 早上好        ',
//   'Good morning 晚安',
// ]

API

alignText

function alignText(
  strings: string[],
  paddingMap?: PaddingMap,
  placeholder?: string
): string[]

type CharWidthRule = {
  test: RegExp | ((char: string) => boolean)
  width: number
}

type PaddingMap = Record<string, CharWidthRule>

Aligns an array of strings by adding padding spaces to make all strings have the same display width.

Parameters

• strings: Array of strings to be aligned
• paddingMap (optional): Custom character width rules. Will be merged with the default CJK rule (width: 2)
• placeholder (optional): Character used for padding. Default: ' ' (U+0020 space)

Returns

An array of aligned strings with appropriate padding added.

Examples

Basic usage

alignText(['Hello', 'Hi', 'Hey'])
// ['Hello', 'Hi   ', 'Hey  ']

Mixed CJK and English

alignText(['名前: 田中', 'Name: John', '이름: 김철수'])
// [
//   '名前: 田中  ',
//   'Name: John  ',
//   '이름: 김철수',
// ]

Custom paddingMap

// Add custom rule while keeping default CJK rule
alignText(['ABC', 'AB', 'A'], {
  uppercase: {
    test: /^[A-Z]$/,
    width: 2,
  },
})
// ['ABC   ', 'AB    ', 'A     ']

Custom placeholder

alignText(['Hello', 'Hi'], {}, '-')
// ['Hello', 'Hi---']

Override default CJK rule

alignText(['你好', '世界'], {
  cjk: {
    test: (char) => /\p{Script=Han}/u.test(char),
    width: 3,
  },
})

License

MIT