src/utils/mimeTypes.js

   1 const mimeDb = require("mime-db");
   2 let optimizedMimeDb = {};
   3
   4 // Initialize the optimized MIME type database, similarly to what "mime-types" library does
   5 Object.keys(mimeDb).forEach((mimeType) => {
   6   const sourcePreference = ["nginx", "apache", undefined, "iana"];
   7   if (
   8     mimeType != "application/octet-stream" &&
   9     mimeDb[mimeType].extensions &&
  10     mimeDb[mimeType].extensions.length > 0
  11   ) {
  12     mimeDb[mimeType].extensions.forEach((extension) => {
  13       if (optimizedMimeDb[extension]) {
  14         const from = sourcePreference.indexOf(
  15           optimizedMimeDb[extension].source
  16         );
  17         const to = sourcePreference.indexOf(mimeDb[mimeType].source);
  18         if (
  19           from != -1 &&
  20           to != -1 &&
  21           (from > to ||
  22             (from === to && mimeType.substring(0, 12) == "application/"))
  23         )
  24           return;
  25       }
  26       optimizedMimeDb[extension] = {
  27         type: mimeType,
  28         charset: mimeDb[mimeType].charset,
  29         source: mimeDb[mimeType].source,
  30         compressible: mimeDb[mimeType].compressible
  31       };
  32     });
  33   }
  34 });
  35
  36 // Function to get the MIME type from the extension
  37 function getMimeType(extension) {
  38   if (!extension || typeof extension !== "string") return false;
  39   const extensionMatch = extension.match(/\.([^.]+)$/);
  40   const normalizedExtension = extensionMatch ? extensionMatch[1] : extension;
  41   if (optimizedMimeDb[normalizedExtension])
  42     return (
  43       optimizedMimeDb[normalizedExtension].type +
  44       (optimizedMimeDb[normalizedExtension].charset
  45         ? "; charset=" +
  46           optimizedMimeDb[normalizedExtension].charset.toLowerCase()
  47         : "")
  48     );
  49   return false;
  50 }
  51
  52 // Function to check if the file is compressible from the extension
  53 function checkIfCompressible(extension) {
  54   if (!extension || typeof extension !== "string") return true;
  55   const extensionMatch = extension.match(/\.([^.]+)$/);
  56   const normalizedExtension = extensionMatch ? extensionMatch[1] : extension;
  57   if (optimizedMimeDb[normalizedExtension])
  58     return optimizedMimeDb[normalizedExtension].compressible === undefined
  59       ? true
  60       : optimizedMimeDb[normalizedExtension].compressible;
  61   return true;
  62 }
  63
  64 module.exports = {
  65   getMimeType: getMimeType,
  66   checkIfCompressible: checkIfCompressible
  67 };