Benchmarking setup (#2366)

* Benchmarking setup

* Get demo data working in benchmark scenario

* Finalize default demo scenario

* Finalize benchmarking setup

perf.rake

@@ -0,0 +1,37 @@
+# Must be in root of repo for derailed_benchmarks to read the benchmark file
+
+require 'bundler'
+Bundler.setup
+
+require 'derailed_benchmarks'
+require 'derailed_benchmarks/tasks'
+
+# Custom auth helper for Maybe's session-based authentication
+class CustomAuth < DerailedBenchmarks::AuthHelper
+  def setup
+    # No setup needed
+  end
+
+  def call(env)
+    # Make sure this user is created in the DB with realistic data before running benchmarks
+    user = User.find_by!(email: "user@maybe.local")
+
+    puts "Found user for benchmarking: #{user.email}"
+
+    # Mimic the way Rails handles browser cookies
+    session = user.sessions.create!
+    key_generator = Rails.application.key_generator
+    secret = key_generator.generate_key('signed cookie')
+    verifier = ActiveSupport::MessageVerifier.new(secret)
+    signed_value = verifier.generate(session.id)
+
+    env['HTTP_COOKIE'] = "session_token=#{signed_value}"
+
+    puts "Setting up session for user: #{user.email}"
+
+    app.call(env)
+  end
+end
+
+# Tells derailed_benchmarks to use our custom auth helper
+DerailedBenchmarks.auth = CustomAuth.new