Allow staff members to enable safe mode, even if disabled

app/controllers/application_controller.rb

@@ -299,7 +299,7 @@ class ApplicationController < ActionController::Base
   SAFE_MODE = "safe_mode"
 
   def resolve_safe_mode
-    return unless SiteSetting.enable_safe_mode?
+    return unless guardian.can_enable_safe_mode?
 
     safe_mode = params[SAFE_MODE]
     if safe_mode

app/controllers/safe_mode_controller.rb

@@ -24,7 +24,7 @@ class SafeModeController < ApplicationController
   protected
 
   def ensure_safe_mode_enabled
-    raise Discourse::NotFound unless SiteSetting.enable_safe_mode?
+    raise Discourse::NotFound unless guardian.can_enable_safe_mode?
   end
 
 end

app/views/common/_discourse_javascript.html.erb

@@ -50,7 +50,7 @@
     Discourse.start();
     Discourse.set('assetVersion','<%= Discourse.assets_digest %>');
     Discourse.Session.currentProp("disableCustomCSS", <%= loading_admin? %>);
-    <%- if SiteSetting.enable_safe_mode? && params["safe_mode"] %>
+    <%- if guardian.can_enable_safe_mode? && params["safe_mode"] %>
     Discourse.Session.currentProp("safe_mode", <%= normalized_safe_mode.inspect.html_safe %>);
     <%- end %>
     Discourse.HighlightJSPath = <%= HighlightJs.path.inspect.html_safe %>;

lib/guardian.rb

@@ -112,6 +112,10 @@ class Guardian
     true
   end
 
+  def can_enable_safe_mode?
+    SiteSetting.enable_safe_mode? || is_staff?
+  end
+
   # Can the user edit the obj
   def can_edit?(obj)
     can_do?(:edit, obj)

spec/components/guardian_spec.rb

@@ -158,6 +158,35 @@ describe Guardian do
     end
   end
 
+  describe "can_enable_safe_mode" do
+    let(:user) { Fabricate.build(:user) }
+    let(:moderator) { Fabricate.build(:moderator) }
+
+    context "when enabled" do
+      before do
+        SiteSetting.enable_safe_mode = true
+      end
+
+      it "can be performed" do
+        expect(Guardian.new.can_enable_safe_mode?).to eq(true)
+        expect(Guardian.new(user).can_enable_safe_mode?).to eq(true)
+        expect(Guardian.new(moderator).can_enable_safe_mode?).to eq(true)
+      end
+    end
+
+    context "when disabled" do
+      before do
+        SiteSetting.enable_safe_mode = false
+      end
+
+      it "can be performed" do
+        expect(Guardian.new.can_enable_safe_mode?).to eq(false)
+        expect(Guardian.new(user).can_enable_safe_mode?).to eq(false)
+        expect(Guardian.new(moderator).can_enable_safe_mode?).to eq(true)
+      end
+    end
+  end
+
   describe "can_defer_flags" do
     let(:post) { Fabricate(:post) }
     let(:user) { post.user }

spec/requests/safe_mode_controller_spec.rb

@@ -15,6 +15,13 @@ RSpec.describe SafeModeController do
         post '/safe-mode'
         expect(response.status).to eq(404)
       end
+
+      it "doesn't raise an error for staff" do
+        SiteSetting.enable_safe_mode = false
+        sign_in(Fabricate(:moderator))
+        post '/safe-mode'
+        expect(response.status).to redirect_to(safe_mode_path)
+      end
     end
 
   end