index.js

const { parsers: typescriptParsers } = require('prettier/parser-typescript')
const { parsers: javascriptParsers } = require('prettier/parser-babel')
const { parsers: htmlParsers } = require('prettier/parser-html')

function preprocessClassName(text) {
  const classNamePattern = /className\s*=\s*["']([^"']+)["']/g
  return text.replace(classNamePattern, (match, classNames) => {
    const cleanClassNames = classNames
      .trim()
      .split(/\s+/)
      .filter((item, index, self) => self.indexOf(item) === index)
      .join(' ')

    return `className="${cleanClassNames}"`
  })
}

function preprocessClass(text) {
  const classPattern = /class\s*=\s*["']([^"']+)["']/g
  return text.replace(classPattern, (match, classNames) => {
    const cleanClassNames = classNames
      .trim()
      .split(/\s+/)
      .filter((item, index, self) => self.indexOf(item) === index)
      .join(' ')

    return `class="${cleanClassNames}"`
  })
}

module.exports = {
  parsers: {
    typescript: {
      ...typescriptParsers.typescript,
      preprocess: preprocessClassName
    },
    babel: {
      ...javascriptParsers.babel,
      preprocess: preprocessClassName
    },
    vue: {
      ...htmlParsers.html,
      preprocess: preprocessClass
    },
    angular: {
      ...htmlParsers.html,
      preprocess: preprocessClass
    },
    html: {
      ...htmlParsers.html,
      preprocess: preprocessClass
    }
  }
}