git.squeep.com Git - squeep-api-dingus/blob - lib/mime-helper.js

   1 /* eslint-disable security/detect-object-injection */
   2 'use strict';
   3
   4 const mimeDb = require('mime-db');
   5
   6 const defaultType = 'application/octet-stream';
   7
   8 /**
   9  * Expects mime-db source data as object:
  10  *   mime-type:
  11  *     source: <String>
  12  *     charset: <String>
  13  *     compressible: <Boolean>
  14  *     extensions: <String[]>
  15  * Populate `extension` as an index from extensions to mime-types.
  16  */
  17 const extension = {};
  18 for (const [mimeType, entry] of Object.entries(mimeDb)) {
  19   for (const ext of entry?.extensions || []) {
  20     if (!(ext in extension)) {
  21       extension[ext] = [];
  22     }
  23     extension[ext].push(mimeType);
  24   }
  25 }
  26
  27 /**
  28  * Return a suitable type for a file extension.
  29  * @param {string} ext file extension
  30  * @param {string} def type to return if no match
  31  * @returns {string}
  32  */
  33 const extensionToMime = (ext, def = defaultType) => extension?.[ext]?.[0] || def;
  34
  35 module.exports = {
  36   extensionToMime,
  37 };