Test individual product loading (#3738)

Tests that each product can be loaded by itself, and repairs appsec to be loadable without tracing having already been loaded.

lib/datadog/appsec/contrib/sinatra/patcher.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require_relative '../../../tracing/contrib/rack/middlewares'
+require_relative '../../../tracing/contrib'
 
 require_relative '../patcher'
 require_relative '../../response'

lib/datadog/appsec/extensions.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require_relative 'configuration'
+require_relative '../core/configuration'
 
 module Datadog
   module AppSec

spec/loading_spec.rb

@@ -0,0 +1,38 @@
+require 'shellwords'
+
+REQUIRES = {
+  'datadog/appsec' => 'Datadog::AppSec',
+  'datadog/core' => 'Datadog::Core',
+  'datadog/kit' => 'Datadog::Kit',
+  'datadog/profiling' => 'Datadog::Profiling',
+  'datadog/tracing' => 'Datadog::Tracing',
+}.freeze
+
+RSpec.describe 'loading of products' do
+  REQUIRES.each do |req, const|
+    context req do
+      let(:code) do
+        <<-E
+          if defined?(Datadog)
+            unless Datadog.constants == [:VERSION]
+              exit 1
+            end
+          end
+
+          require "#{req}"
+
+          unless defined?(#{const})
+            exit 1
+          end
+
+          exit 0
+        E
+      end
+
+      it 'loads successfully by itself' do
+        rv = system("ruby -e #{Shellwords.shellescape(code)}")
+        expect(rv).to be true
+      end
+    end
+  end
+end