hunk.code_window: 	switch settings.DriverName {
   	case driverS3:
   		backend, err := NewS3FileBackend(settings)
   		if err != nil {
   			return nil, errors.Wrap(err, "unable to connect to the s3 backend")
   		}
   		return backend, nil
  
hunk.labels: keep keep replace keep keep keep keep
hunk.after_edit: 		newBackendFn := NewS3FileBackend
   		if !canBeCloud {
   			newBackendFn = NewS3FileBackendWithoutBifrost
   		}
   		backend, err := newBackendFn(settings)
  
hunk.file_path: server/platform/shared/filestore/filesstore.go
hunk.type: replace
file: # Link Preview Tests
  
  Link previews should embed previews of the contents of a hyperlink from a message or comment in the center channel directly below the message or comment.
  
  Post location variation: 
  
  1. Post message in center channel with RHS closed (Expected: preview of first link renders under message) 
  2. Post message in center channel with RHS open (Expected: preview of first link renders under message) 
  3. Post comment in RHS (Expected: link preview does not render) 
  4. View comment in center channel with RHS closed (Expected: preview of first link renders under message) 
  5. View comment in center channel with RHS open (Expected: preview of first link renders under message) 
  6. Search for post in RHS with link (Expected: no previews render in search results) 
  
  Test the above variations with the below sample messages (e.g. 1-A, 2-B, 3-C, 4-D, etc.) 
  
  ```
  #### A) No link preview
  
  Link 1 example: https://en.wikipedia.org/wiki/Olympus_Mons
  
  Link 2 example: http://www.techmeme.com/
  
  Link 3 example: https://about.gitlab.com/
  ```
  
  ```
  #### B) Link preview without an image
  
  Link 1 example: https://coveralls.io/builds/9818822/source?filename=app%2Faudit.go
  ```
  
  ```
  #### C) Link preview with image in top right corner
  
  Link 1 example: http://www.theglobeandmail.com/news/national/three-canadians-shortlisted-for-global-teacher-prize/article33429901/
  
  Link 2 example: https://twitter.com/ArchieComics/status/813007703861841920
  
  Link 3 example: https://github.com/mattermost
  
  Link 4 example: http://stackoverflow.com/questions/36650437/using-mattermost-api-via-gitlab-oauth-as-an-end-user-with-username-and-password
  ```
  
  ```
  #### D) Link preview with image at the bottom
  
  If "Account Settings > Display > Default appearance of image link previews" is set to "Collapsed", you must click the expand arrows to display the image.
  
  Link 1 example: https://www.yahoo.com/news/panasonic-unveils-solar-roof-may-212400917.html
  
  Link 2 example: https://mattermost.com
  
  ```
  