From 1fa248b5a79c67ff8d3932daf5cb34a53dd8449c Mon Sep 17 00:00:00 2001
From: Elias Nahum <nahumhbl@gmail.com>
Date: Wed, 17 Aug 2022 13:29:58 -0400
Subject: [PATCH] [Gekidou] Fix mimeType undefined in isImage utility (#6581)

* Fix mimeType undefined in isImage utility

* Apply suggestion

Co-authored-by: Jason Frerich <jason.frerich@mattermost.com>

* remove unecessary return

Co-authored-by: Jason Frerich <jason.frerich@mattermost.com>
---
 app/utils/file/index.ts | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/app/utils/file/index.ts b/app/utils/file/index.ts
index 405aa6f69e..90c924b032 100644
--- a/app/utils/file/index.ts
+++ b/app/utils/file/index.ts
@@ -267,9 +267,16 @@ export const isImage = (file?: FileInfo | FileModel) => {
         return false;
     }
 
-    const mimeType = 'mime_type' in file ? file.mime_type : file.mimeType;
+    if (isGif(file)) {
+        return true;
+    }
 
-    return (isGif(file) || mimeType.startsWith('image/'));
+    let mimeType = 'mime_type' in file ? file.mime_type : file.mimeType;
+    if (!mimeType) {
+        mimeType = lookupMimeType(file.extension) || lookupMimeType(file.name);
+    }
+
+    return Boolean(mimeType?.startsWith('image/'));
 };
 
 export const isDocument = (file?: FileInfo | FileModel) => {