ui-template-muc/src/utils/camelcase.js

A fantastic mobile ui lib implement by Vue

import {isArray} from '@utils/helpers'
const preserveCamelCase = string => {
  let isLastCharLower = false
  let isLastCharUpper = false
  let isLastLastCharUpper = false

  for (let i = 0; i < string.length; i++) {
    const character = string[i]
    if (isLastCharLower && /[a-zA-Z]/.test(character) && character.toUpperCase() === character) {
      string = string.slice(0, i) + '-' + string.slice(i)
      isLastCharLower = false
      isLastLastCharUpper = isLastCharUpper
      isLastCharUpper = true
      i++
    } else if (isLastCharUpper && isLastLastCharUpper && /[a-zA-Z]/.test(character) && character.toLowerCase() === character) {
      string = string.slice(0, i - 1) + '-' + string.slice(i - 1)
      isLastLastCharUpper = isLastCharUpper
      isLastCharUpper = false
      isLastCharLower = true
    } else {
      isLastCharLower = character.toLowerCase() === character && character.toUpperCase() !== character
      isLastLastCharUpper = isLastCharUpper
      isLastCharUpper = character.toUpperCase() === character && character.toLowerCase() !== character
    }
  }

  return string
}

const camelCase = (input, options) => {
  if (!(typeof input === 'string' || isArray(input))) {
    throw new TypeError('Expected the input to be `string | string[]`')
  }

  options = Object.assign({
    pascalCase: false
  }, options)

  const postProcess = x => options.pascalCase ? x.charAt(0).toUpperCase() + x.slice(1) : x

  if (Array.isArray(input)) {
    input = input.map(x => x.trim())
    .filter(x => x.length)
      .join('-')
  } else {
    input = input.trim()
  }

  if (input.length === 0) {
    return ''
  }

  if (input.length === 1) {
    return options.pascalCase ? input.toUpperCase() : input.toLowerCase()
  }

  const hasUpperCase = input !== input.toLowerCase()

  if (hasUpperCase) {
    input = preserveCamelCase(input)
  }

  input = input
    .replace(/^[_.\- ]+/, '')
    .toLowerCase()
    .replace(/[_.\- ]+(\w|$)/g, (_, p1) => p1.toUpperCase())
    .replace(/\d+(\w|$)/g, m => m.toUpperCase())
  return postProcess(input)
}
export function uppercamelcase (input, options) {
  let str = camelCase(input, options)
  return str.charAt(0).toUpperCase() + str.slice(1)
}
export function lowercamelcase (input, options) {
  let str = camelCase(input, options)
  return str.charAt(0).toLowerCase() + str.slice(1)
}