FEATURE: allow staff to send multiple invites to same email

app/controllers/invites_controller.rb

@@ -35,6 +35,11 @@ class InvitesController < ApplicationController
 
     guardian.ensure_can_invite_to_forum!(group_ids)
 
+    invite_exists = Invite.where(email: params[:email], invited_by_id: current_user.id).first
+    if invite_exists
+      guardian.ensure_can_send_multiple_invites!(current_user)
+    end
+
     if Invite.invite_by_email(params[:email], current_user, topic=nil,  group_ids)
       render json: success_json
     else

app/models/invite.rb

@@ -205,6 +205,6 @@ end
 #
 # Indexes
 #
-#  index_invites_on_email_and_invited_by_id  (email,invited_by_id) UNIQUE
+#  index_invites_on_email_and_invited_by_id  (email,invited_by_id)
 #  index_invites_on_invite_key               (invite_key) UNIQUE
 #

db/migrate/20140729092525_remove_unique_constraint_from_invites_index.rb

@@ -0,0 +1,11 @@
+class RemoveUniqueConstraintFromInvitesIndex < ActiveRecord::Migration
+  def up
+    remove_index :invites, [:email, :invited_by_id]
+    add_index :invites, [:email, :invited_by_id], unique: false
+  end
+
+  def down
+    remove_index :invites, [:email, :invited_by_id]
+    add_index :invites, [:email, :invited_by_id], unique: true
+  end
+end

lib/guardian.rb

@@ -214,6 +214,10 @@ class Guardian
     user.admin?
   end
 
+  def can_send_multiple_invites?(user)
+    user.staff?
+  end
+
   def can_see_private_messages?(user_id)
     is_admin? || (authenticated? && @user.id == user_id)
   end

spec/controllers/invites_controller_spec.rb

@@ -53,6 +53,14 @@ describe InvitesController do
         response.should_not be_success
       end
 
+      it "fails for normal user if invite email already exists" do
+        user = log_in(:elder)
+        invite = Invite.invite_by_email("invite@example.com", user)
+        invite.reload
+        post :create, email: invite.email
+        response.should_not be_success
+      end
+
       it "allows admins to invite to groups" do
         group = Fabricate(:group)
         log_in(:admin)
@@ -60,6 +68,14 @@ describe InvitesController do
         response.should be_success
         Invite.find_by(email: email).invited_groups.count.should == 1
       end
+
+      it "allows admin to send multiple invites to same email" do
+        user = log_in(:admin)
+        invite = Invite.invite_by_email("invite@example.com", user)
+        invite.reload
+        post :create, email: invite.email
+        response.should be_success
+      end
     end
 
   end