Improve error reporting on users API

* users (#6878, #3526, #4209): Validation error messages are now exposed through 400 responses, 409 response are sent in case of duplicate email or username
* MRs (#5335): 409 responses are sent in case of duplicate merge request (source/target branches), 422 responses are sent when submiting MR fo/from unrelated forks
* issues
* labels
* projects

1 files changed, 3 insertions, 2 deletions

diff --git a/lib/api/project_snippets.rb b/lib/api/project_snippets.rb
index 8e09fff6843..0c2d282f785 100644
--- a/lib/api/project_snippets.rb
+++ b/lib/api/project_snippets.rb
@@ -56,7 +56,7 @@ module API
         if @snippet.save
           present @snippet, with: Entities::ProjectSnippet
         else
-          not_found!
+          render_validation_error!(@snippet)
         end
       end
 
@@ -80,7 +80,7 @@ module API
         if @snippet.update_attributes attrs
           present @snippet, with: Entities::ProjectSnippet
         else
-          not_found!
+          render_validation_error!(@snippet)
         end
       end
 
@@ -97,6 +97,7 @@ module API
           authorize! :modify_project_snippet, @snippet
           @snippet.destroy
         rescue
+          not_found!('Snippet')
         end
       end