Filter by `None`/`Any` for labels in issues/mrs API

By using the parameters `?labels=None|Any` the user can filter
issues/mrs from the API that has `none/any` label.

Affected endpoints are:

- /api/issues
- /api/projects/:id/issues
- /api/groups/:id/issues
- /api/merge_requests
- /api/projects/:id/merge_requests
- /api/groups/:id/merge_requests

1 files changed, 10 insertions, 1 deletions

diff --git a/app/finders/issuable_finder.rb b/app/finders/issuable_finder.rb
index fdc630cbf72..e04e3a2a7e0 100644
--- a/app/finders/issuable_finder.rb
+++ b/app/finders/issuable_finder.rb
@@ -210,7 +210,14 @@ class IssuableFinder
   end
 
   def filter_by_no_label?
-    labels? && params[:label_name].include?(Label::None.title)
+    downcased = label_names.map(&:downcase)
+
+    # Label::NONE is deprecated and should be removed in 12.0
+    downcased.include?(FILTER_NONE) || downcased.include?(Label::NONE)
+  end
+
+  def filter_by_any_label?
+    label_names.map(&:downcase).include?(FILTER_ANY)
   end
 
   def labels
@@ -465,6 +472,8 @@ class IssuableFinder
     items =
       if filter_by_no_label?
         items.without_label
+      elsif filter_by_any_label?
+        items.any_label
       else
         items.with_label(label_names, params[:sort])
       end