Mapping file extensions to font awesome classes for easy UI display

mappingExtensionsToFA.js

const fontAwesomeIconClasses = {
  // Media
  "png": "fa-file-image-o",
  "jpg": "fa-file-image-o",
  "jpeg": "fa-file-image-o",
  "gif": "fa-file-image-o",
  "mp3": "fa-file-audio-o",
  "mpg": "fa-file-video-o",
  "mpeg": "fa-file-video-o",
  "mp4": "fa-file-video-o",
  // Documents
  "pdf": "fa-file-pdf-o",
  "pages": "fa-file-word-o",
  "doc": "fa-file-word-o",
  "docx": "fa-file-word-o",
  "odt": "fa-file-word-o",
  "xls": "fa-file-excel-o",
  "numbers": "fa-file-excel-o",
  "xlsx": "fa-file-excel-o",
  "ods": "fa-file-excel-o",
  "ppt": "fa-file-powerpoint-o",
  "pptx": "fa-file-powerpoint-o",
  "key": "fa-file-powerpoint-o",
  "odp": "fa-file-powerpoint-o",
  "txt": "fa-file-text-o",
  "htm": "fa-file-code-o",
  "html": "fa-file-code-o",
  "json": "fa-file-code-o",
  // Archives
  "gzip": "fa-file-archive-o",
  "zip": "fa-file-archive-o"
}

function isValidString(o) {
  if (o === null) {
    return false;
  }
  if (
    typeof o == "string" ||
    (typeof o == "object" && o.constructor === String)
  ) {
    return o.length > 0;
  } else {
    return false;
  }
}

function getFontAwesomeIconFromMIME(filename) {
  const extension = filename.split('.').pop()
  const result = fontAwesomeIconClasses[extension]
  if (isValidString(result)) { return result }
  else { return "fa-file-o" }
}

const icon = getFontAwesomeIconFromMIME('png')
console.log(icon)