Default value for exc error

docs/adapters/testing.md

@@ -33,7 +33,7 @@ conn = Faraday.new do |builder|
 
     # test exceptions too
     stub.get('/boom') do
-      raise Faraday::ConnectionFailed, nil
+      raise Faraday::ConnectionFailed
     end
   end
 end

examples/client_spec.rb

@@ -56,7 +56,7 @@ def sushi(jname, params: {})
 
   it 'handles exception' do
     stubs.get('/ebi') do
-      raise Faraday::ConnectionFailed, nil
+      raise Faraday::ConnectionFailed
     end
 
     expect { client.sushi('ebi') }.to raise_error(Faraday::ConnectionFailed)

examples/client_test.rb

@@ -60,7 +60,7 @@ def test_sushi_not_found
   def test_sushi_exception
     stubs = Faraday::Adapter::Test::Stubs.new
     stubs.get('/ebi') do
-      raise Faraday::ConnectionFailed, nil
+      raise Faraday::ConnectionFailed
     end
 
     cli = client(stubs)

lib/faraday/error.rb

@@ -6,7 +6,7 @@ module Faraday
   class Error < StandardError
     attr_reader :response, :wrapped_exception
 
-    def initialize(exc, response = nil)
+    def initialize(exc = nil, response = nil)
       @wrapped_exception = nil unless defined?(@wrapped_exception)
       @response = nil unless defined?(@response)
       super(exc_msg_and_response!(exc, response))