Use mime-types for extension in download

node/src/handlers/get-file-set-download.js

@@ -8,7 +8,7 @@ const { apiTokenName } = require("../environment");
 const ApiToken = require("../api/api-token");
 const axios = require("axios").default;
 const cookie = require("cookie");
-
+const mime = require("mime-types");
 const opensearchResponse = require("../api/response/opensearch");
 const path = require("path");
 
@@ -104,14 +104,6 @@ function derivativeKey(doc) {
   return "derivatives/" + prefix + "/" + id;
 }
 
-function extensionFromMimeType(mimeType) {
-  const parts = mimeType.split("/");
-  if (parts.length > 1) {
-    return parts[1];
-  }
-  return "";
-}
-
 async function getDownloadLink(doc) {
   const clientParams = {};
   const bucket = process.env.PYRAMID_BUCKET;
@@ -122,7 +114,7 @@ async function getDownloadLink(doc) {
     Key: key,
     ResponseContentDisposition: `attachment; filename=${
       doc._source.label
-    }.${extensionFromMimeType(doc._source.mime_type)}`,
+    }.${mime.extension(doc._source.mime_type)}`,
   };
 
   const client = new S3Client(clientParams);