micro-mdx-parser/src/utils/index.js

A tiny parser to convert markdown or html into JSON

function getTextBetweenChars(text, start, end) {
  return text.slice(start, end)
}

function startsWith(str, searchString, position) {
  return str.substr(position || 0, searchString.length) === searchString
}

function endsWith(str, searchString, position) {
  const index = (position || str.length) - searchString.length
  const lastIndex = str.lastIndexOf(searchString, index)
  return lastIndex !== -1 && lastIndex === index
}

function stringIncludes(str, searchString, position) {
  return str.indexOf(searchString, position || 0) !== -1
}

function isRealNaN(x) {
  return typeof x === 'number' && isNaN(x)
}

function arrayIncludes (array, searchElement, position) {
  const len = array.length
  if (len === 0) return false

  const lookupIndex = position | 0
  const isNaNElement = isRealNaN(searchElement)
  let searchIndex = lookupIndex >= 0 ? lookupIndex : len + lookupIndex
  while (searchIndex < len) {
    const element = array[searchIndex++]
    if (element === searchElement) return true
    if (isNaNElement && isRealNaN(element)) return true
  }

  return false
}

module.exports = {
  startsWith,
  endsWith,
  stringIncludes,
  isRealNaN,
  arrayIncludes,
  getTextBetweenChars
}