Add test for external checks loading

lib/brakeman/checks.rb

@@ -181,4 +181,7 @@ class Brakeman::Checks
   end
 end
 
-Brakeman::Checks.initialize_checks File.expand_path(File.join(File.dirname(__FILE__), "checks"))
+#Load all files in checks/ directory
+Dir.glob("#{File.expand_path(File.dirname(__FILE__))}/checks/*.rb").sort.each do |f|
+  require f.match(/(brakeman\/checks\/.*)\.rb$/)[0]
+end

test/apps/rails4/external_checks/check_external_check_test.rb

+require 'brakeman/checks/base_check'
+
+#Verify that checks external to the checks/ dir are added by the additional_checks_path options flag
+class Brakeman::CheckExternalCheckTest < Brakeman::BaseCheck
+  Brakeman::Checks.add self
+
+  @description = "An external check that does nothing, used for testing"
+
+  def run_check
+  end
+end

test/tests/rails4.rb

 abort "Please run using test/test.rb" unless defined? BrakemanTester
 
-Rails4 = BrakemanTester.run_scan "rails4", "Rails 4"
+EXTERNAL_CHECKS_PATH = File.expand_path(File.join(File.dirname(__FILE__), "..", "/apps/rails4/external_checks"))
+Rails4 = BrakemanTester.run_scan "rails4", "Rails 4", {additional_checks_path: [EXTERNAL_CHECKS_PATH]}
 
 class Rails4Tests < Test::Unit::TestCase
   include BrakemanTester::FindWarning
   include BrakemanTester::CheckExpected
-  
+
   def report
     Rails4
   end
@@ -581,4 +582,8 @@ class Rails4Tests < Test::Unit::TestCase
       :relative_path => "app/controllers/application_controller.rb",
       :user_input => nil
   end
+
+  def test_external_checks
+    # TODO: check for external check class being loaded here
+  end
 end