use lazy ajax filter dropdown for runner tags

the potential number of available runner tags is too large to load it
statically to a dropdown. we use the same lazy loaded dropdown as is
used for the users dropdown already.

1 files changed, 45 insertions, 0 deletions

diff --git a/app/finders/autocomplete/acts_as_taggable_on/tags_finder.rb b/app/finders/autocomplete/acts_as_taggable_on/tags_finder.rb
new file mode 100644
index 00000000000..65ae90c08b4
--- /dev/null
+++ b/app/finders/autocomplete/acts_as_taggable_on/tags_finder.rb
@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+module Autocomplete
+  module ActsAsTaggableOn
+    class TagsFinder
+      LIMIT = 20
+
+      def initialize(taggable_type:, params:)
+        @taggable_type = taggable_type
+        @params = params
+      end
+
+      def execute
+        @tags = @taggable_type.all_tags
+
+        search!
+        limit!
+
+        @tags
+      end
+
+      def search!
+        search = @params[:search]
+
+        return unless search
+
+        if search.empty?
+          @tags = @taggable_type.none
+          return
+        end
+
+        @tags =
+          if search.length >= Gitlab::SQL::Pattern::MIN_CHARS_FOR_PARTIAL_MATCHING
+            @tags.named_like(search)
+          else
+            @tags.named(search)
+          end
+      end
+
+      def limit!
+        @tags = @tags.limit(LIMIT) # rubocop: disable CodeReuse/ActiveRecord
+      end
+    end
+  end
+end