raise the exception rather than the exception class - Fix Issue #1785

gemfiles/Gemfile.ruby-19

@@ -9,4 +9,5 @@ gem 'xpath', :git => 'git://github.com/jnicklas/xpath.git'
 gem 'term-ansicolor', '< 1.4.0'
 gem 'tins', '< 1.7.0'  # 1.7.0 requires ruby 2.0
 
-gem 'selenium-webdriver', '< 3.0.0' # 3.0 requires ruby 2.0
+gem 'selenium-webdriver', '< 3.0.0' # 3.0 requires ruby 2.0
+gem 'addressable', '< 2.5.0' # 2.5 requires public_suffix which requires ruby 2.0

lib/capybara/session.rb

@@ -125,7 +125,8 @@ module Capybara
         begin
           raise CapybaraError, "Your application server raised an error - It has been raised in your test code because Capybara.raise_server_errors == true"
         rescue CapybaraError
-          raise @server.error.class, @server.error.message, @server.error.backtrace
+          #needed to get the cuase set correctly in JRuby -- otherwise we could just do raise @server.error
+          raise @server.error, @server.error.message, @server.error.backtrace
         end
       end
     ensure

lib/capybara/spec/session/node_spec.rb

@@ -428,6 +428,17 @@ Capybara::SpecHelper.spec "node" do
         expect(e.cause.message).to match /Your application server raised an error/
       end
     end
+
+    it "sets an explanatory exception as the cause of server exceptions with errors with initializers", requires: [:server, :js], twtw: true do
+      skip "This version of ruby doesn't support exception causes" unless Exception.instance_methods.include? :cause
+      quietly { @session.visit("/other_error") }
+      expect do
+        @session.find(:css, 'span')
+      end.to raise_error(TestApp::TestAppOtherError) do |e|
+        expect(e.cause).to be_a Capybara::CapybaraError
+        expect(e.cause.message).to match /Your application server raised an error/
+      end
+    end
   end
 
   def be_an_invalid_element_error(session)

lib/capybara/spec/test_app.rb

@@ -6,7 +6,12 @@ require 'yaml'
 
 class TestApp < Sinatra::Base
   class TestAppError < StandardError; end
-
+  class TestAppOtherError < StandardError
+    def initialize(string1, msg)
+      @something = string1
+      @message = msg
+    end
+  end
   set :root, File.dirname(__FILE__)
   set :static, true
   set :raise_errors, true
@@ -125,6 +130,10 @@ class TestApp < Sinatra::Base
     raise TestAppError, "some error"
   end
 
+  get '/other_error' do
+    raise TestAppOtherError.new("something", "other error")
+  end
+
   get '/load_error' do
     raise LoadError
   end