Limit autocomplete to currently selected items

app/assets/javascripts/gfm_auto_complete.js.es6

@@ -51,6 +51,11 @@
         if (!GitLab.GfmAutoComplete.dataLoaded) {
           return this.at;
         } else {
+          if (value.indexOf("unlabel") !== -1) {
+            GitLab.GfmAutoComplete.input.atwho('load', '~', GitLab.GfmAutoComplete.cachedData.unlabels);
+          } else {
+            GitLab.GfmAutoComplete.input.atwho('load', '~', GitLab.GfmAutoComplete.cachedData.labels);
+          }
           return value;
         }
       }
@@ -352,3 +357,4 @@
   };
 
 }).call(this);
+

app/controllers/projects_controller.rb

@@ -144,13 +144,15 @@ class ProjectsController < Projects::ApplicationController
 
     autocomplete = ::Projects::AutocompleteService.new(@project, current_user)
     participants = ::Projects::ParticipantsService.new(@project, current_user).execute(noteable)
+    unlabels = autocomplete.unlabels(noteable)
 
     @suggestions = {
       emojis: Gitlab::AwardEmoji.urls,
       issues: autocomplete.issues,
       milestones: autocomplete.milestones,
       mergerequests: autocomplete.merge_requests,
-      labels: autocomplete.labels,
+      labels: autocomplete.labels - unlabels,
+      unlabels: unlabels,
       members: participants,
       commands: autocomplete.commands(noteable, params[:type])
     }

app/services/projects/autocomplete_service.rb

@@ -13,7 +13,14 @@ module Projects
     end
 
     def labels
-      LabelsFinder.new(current_user, project_id: project.id).execute.select([:title, :color])
+      LabelsFinder.new(current_user, project_id: project.id).execute.
+        pluck(:title, :color).map { |l| { title: l.first, color: l.second } }
+    end
+
+    def unlabels(noteable)
+      return [] unless noteable && noteable.respond_to?(:labels)
+
+      noteable.labels.pluck(:title, :color).map { |l| { title: l.first, color: l.second } }
     end
 
     def commands(noteable, type)

changelogs/unreleased/22680-unlabel-limit-autocomplete-to-selected-items.yml

@@ -0,0 +1,4 @@
+---
+title: Limit autocomplete to currently selected items for unlabel slash command
+merge_request: 22680
+author: Akram Fares