FEATURE: allow "developer" account flagging via developers table

This mechanism for flagging developer accounts will eventually replace
DISCOURSE_DEVELOPER_EMAILS

app/models/developer.rb

@@ -0,0 +1,22 @@
+require_dependency 'distributed_cache'
+
+class Developer < ActiveRecord::Base
+  belongs_to :user
+
+  after_save :rebuild_cache
+  after_destroy :rebuild_cache
+
+  @id_cache = DistributedCache.new('developer_ids')
+
+  def self.user_ids
+    @id_cache["ids"] ||= rebuild_cache
+  end
+
+  def self.rebuild_cache
+    @id_cache["ids"] = Set.new(Developer.pluck(:user_id))
+  end
+
+  def rebuild_cache
+    Developer.rebuild_cache
+  end
+end

db/migrate/20160727233044_create_developers_table.rb

@@ -0,0 +1,7 @@
+class CreateDevelopersTable < ActiveRecord::Migration
+  def change
+    create_table :developers do |t|
+      t.integer :user_id, null: false
+    end
+  end
+end

lib/guardian.rb

@@ -74,7 +74,8 @@ class Guardian
       (
         Rails.configuration.respond_to?(:developer_emails) &&
         Rails.configuration.developer_emails.include?(@user.email)
-      )
+      ) ||
+      Developer.user_ids.include?(@user.id)
     )
   end
 

spec/models/developer_spec.rb

@@ -0,0 +1,20 @@
+require 'rails_helper'
+
+describe Developer do
+  it "can correctly flag developer accounts" do
+    user = Fabricate(:user)
+    guardian = Guardian.new(user)
+
+    expect(guardian.is_developer?).to eq(false)
+
+    Developer.create!(user_id: user.id)
+
+    # not an admin so not a developer yet
+    expect(guardian.is_developer?).to eq(false)
+
+    user.update_columns(admin: true)
+
+    expect(guardian.is_developer?).to eq(true)
+  end
+end
+