1 files changed, 26 insertions, 1 deletions

diff --git a/server/helpers/custom-validators/misc.ts b/server/helpers/custom-validators/misc.ts
index 3903884ea..8a270b777 100644
--- a/server/helpers/custom-validators/misc.ts
+++ b/server/helpers/custom-validators/misc.ts
@@ -1,3 +1,4 @@
+import 'multer'
 import * as validator from 'validator'
 
 function exists (value: any) {
@@ -28,6 +29,29 @@ function isBooleanValid (value: string) {
   return typeof value === 'boolean' || (typeof value === 'string' && validator.isBoolean(value))
 }
 
+function isFileValid (
+  files: { [ fieldname: string ]: Express.Multer.File[] } | Express.Multer.File[],
+  mimeTypeRegex: string,
+  field: string,
+  optional = false
+) {
+  // Should have files
+  if (!files) return optional
+  if (isArray(files)) return optional
+
+  // Should have a file
+  const fileArray = files[ field ]
+  if (!fileArray || fileArray.length === 0) {
+    return optional
+  }
+
+  // The file should exist
+  const file = fileArray[ 0 ]
+  if (!file || !file.originalname) return false
+
+  return new RegExp(`^${mimeTypeRegex}$`, 'i').test(file.mimetype)
+}
+
 // ---------------------------------------------------------------------------
 
 export {
@@ -37,5 +61,6 @@ export {
   isUUIDValid,
   isIdOrUUIDValid,
   isDateValid,
-  isBooleanValid
+  isBooleanValid,
+  isFileValid
 }