FEATURE: introduces minimum trust level for polls (#5391)

* FEATURE: introduces minimum trust level for polls

This commit makes `poll_enabled` less misleading and introduces `poll_minimum_trust_level_to_create`. If poll are enabled they will always be cooked, and if you have the required trust level you can create polls. As a side effect, it also fixes a bug where rebaking a post created by staff member when `poll_enabled=false` would end up not cooking it.

It also adds more tests to ensure settings are respected.

* admins should be whitelisted

* checks for admin in post validation

* test for >= instead of == trust level

plugins/poll/spec/controllers/posts_controller_spec.rb

@@ -336,4 +336,100 @@ describe PostsController do
 
   end
 
+  describe "disabled polls" do
+    before do
+      SiteSetting.poll_enabled = false
+    end
+
+    it "doesn’t cook the poll" do
+      post :create, params: {
+        title: title, raw: "[poll]\n- A\n- B\n[/poll]"
+      }, format: :json
+
+      expect(response).to be_success
+      json = ::JSON.parse(response.body)
+      expect(json["cooked"]).to eq("<p>[poll]</p>\n<ul>\n<li>A</li>\n<li>B<br>\n[/poll]</li>\n</ul>")
+    end
+  end
+
+  describe "insufficient trust level" do
+    before do
+      SiteSetting.poll_minimum_trust_level_to_create = 2
+    end
+
+    it "invalidates the post" do
+      log_in_user(Fabricate(:user, trust_level: 1))
+
+      post :create, params: {
+        title: title, raw: "[poll]\n- A\n- B\n[/poll]"
+      }, format: :json
+
+      expect(response).not_to be_success
+      json = ::JSON.parse(response.body)
+      expect(json["errors"][0]).to eq(
+        I18n.t("poll.insufficient_trust_level_to_create",
+          current: user.trust_level,
+          required: SiteSetting.poll_minimum_trust_level_to_create
+        )
+      )
+    end
+  end
+
+  describe "equal trust level" do
+    before do
+      SiteSetting.poll_minimum_trust_level_to_create = 2
+    end
+
+    it "validates the post" do
+      log_in_user(Fabricate(:user, trust_level: 2))
+
+      post :create, params: {
+        title: title, raw: "[poll]\n- A\n- B\n[/poll]"
+      }, format: :json
+
+      expect(response).to be_success
+      json = ::JSON.parse(response.body)
+      expect(json["cooked"]).to match("data-poll-")
+      expect(json["polls"]["poll"]).to be
+    end
+  end
+
+  describe "superior trust level" do
+    before do
+      SiteSetting.poll_minimum_trust_level_to_create = 2
+    end
+
+    it "validates the post" do
+      log_in_user(Fabricate(:user, trust_level: 3))
+
+      post :create, params: {
+        title: title, raw: "[poll]\n- A\n- B\n[/poll]"
+      }, format: :json
+
+      expect(response).to be_success
+      json = ::JSON.parse(response.body)
+      expect(json["cooked"]).to match("data-poll-")
+      expect(json["polls"]["poll"]).to be
+    end
+  end
+
+
+  describe "admin with insufficient trust level" do
+    before do
+      SiteSetting.poll_minimum_trust_level_to_create = 2
+    end
+
+    it "validates the post" do
+      log_in_user(Fabricate(:user, admin: true, trust_level: 1))
+
+      post :create, params: {
+        title: title, raw: "[poll]\n- A\n- B\n[/poll]"
+      }, format: :json
+
+      expect(response).to be_success
+      json = ::JSON.parse(response.body)
+      expect(json["cooked"]).to match("data-poll-")
+      expect(json["polls"]["poll"]).to be
+    end
+  end
 end