FEATURE: restrict tags to be used in a category

spec/integration/category_tag_spec.rb

@@ -0,0 +1,55 @@
+# encoding: UTF-8
+
+require 'rails_helper'
+require_dependency 'post_creator'
+
+describe "category tag restrictions" do
+  let!(:tag1) { Fabricate(:tag) }
+  let!(:tag2) { Fabricate(:tag) }
+  let!(:tag3) { Fabricate(:tag) }
+  let!(:tag4) { Fabricate(:tag) }
+
+  let(:user)  { Fabricate(:user) }
+  let(:admin) { Fabricate(:admin) }
+
+  before do
+    SiteSetting.tagging_enabled = true
+    SiteSetting.min_trust_to_create_tag = 0
+    SiteSetting.min_trust_level_to_tag_topics = 0
+  end
+
+  context "tags restricted to one category" do
+    let(:category_with_tags) { Fabricate(:category) }
+    let(:other_category)     { Fabricate(:category) }
+
+    before do
+      category_with_tags.tags = [tag1, tag2]
+    end
+
+    it "tags belonging to that category can only be used there" do
+      post = create_post(category: category_with_tags, tags: [tag1.name, tag2.name, tag3.name])
+      expect(post.topic.tags.map(&:name).sort).to eq([tag1.name, tag2.name].sort)
+
+      post = create_post(category: other_category, tags: [tag1.name, tag2.name, tag3.name])
+      expect(post.topic.tags.map(&:name)).to eq([tag3.name])
+    end
+
+    it "search can show only permitted tags" do
+      expect(DiscourseTagging.filter_allowed_tags(Tag.all, Guardian.new(user)).count).to eq(Tag.count)
+      expect(DiscourseTagging.filter_allowed_tags(Tag.all, Guardian.new(user), {for_input: true, category: category_with_tags}).pluck(:name).sort).to eq([tag1.name, tag2.name].sort)
+      expect(DiscourseTagging.filter_allowed_tags(Tag.all, Guardian.new(user), {for_input: true}).pluck(:name).sort).to eq([tag3.name, tag4.name].sort)
+    end
+
+    it "can't create new tags in a restricted category" do
+      post = create_post(category: category_with_tags, tags: [tag1.name, "newtag"])
+      expect(post.topic.tags.map(&:name)).to eq([tag1.name])
+      post = create_post(category: category_with_tags, tags: [tag1.name, "newtag"], user: admin)
+      expect(post.topic.tags.map(&:name)).to eq([tag1.name])
+    end
+
+    it "can create new tags in a non-restricted category" do
+      post = create_post(category: other_category, tags: [tag3.name, "newtag"])
+      expect(post.topic.tags.map(&:name).sort).to eq([tag3.name, "newtag"].sort)
+    end
+  end
+end