Define the symlink mode as a constant on the Blob model

app/models/blob.rb

@@ -6,6 +6,8 @@ class Blob < SimpleDelegator
   include BlobLanguageFromGitAttributes
   include BlobActiveModel
 
+  MODE_SYMLINK = '120000' # The STRING 120000 is the git-reported octal filemode for a symlink
+
   CACHE_TIME = 60 # Cache raw blobs referred to by a (mutable) ref for 1 minute
   CACHE_TIME_IMMUTABLE = 3600 # Cache blobs referred to by an immutable reference for 1 hour
 

app/views/projects/blob/_header_content.html.haml

@@ -7,7 +7,7 @@
   = copy_file_path_button(blob.path)
 
   %small.mr-1
-    - if blob.mode == '120000'
+    - if blob.mode == Blob::MODE_SYMLINK
       = _('Symbolic link') << ' ·'
     = number_to_human_size(blob.raw_size)