Add config.default_method_for_update to support PATCH

PATCH is the correct HTML verb to map to the #update action. The
semantics for PATCH allows for partial updates, whereas PUT requires a
complete replacement.

Changes:
* adds config.default_method_for_update you can set to :patch
* optionally use PATCH instead of PUT in resource routes and forms
* adds the #patch verb to routes to detect PATCH requests
* adds #patch? to Request
* changes documentation and comments to indicate support for PATCH

This change maintains complete backwards compatibility by keeping :put
as the default for config.default_method_for_update.

2 files changed, 10 insertions, 6 deletions

diff --git a/activeresource/test/cases/format_test.rb b/activeresource/test/cases/format_test.rb
index 30342ecc74..315f9db1eb 100644
--- a/activeresource/test/cases/format_test.rb
+++ b/activeresource/test/cases/format_test.rb
@@ -11,11 +11,15 @@ class FormatTest < ActiveSupport::TestCase
   end
 
   def test_http_format_header_name
-    header_name = ActiveResource::Connection::HTTP_FORMAT_HEADER_NAMES[:get]
-    assert_equal 'Accept', header_name
+    [:get, :head].each do |verb|
+      header_name = ActiveResource::Connection::HTTP_FORMAT_HEADER_NAMES[verb]
+      assert_equal 'Accept', header_name
+    end
 
-    headers_names = [ActiveResource::Connection::HTTP_FORMAT_HEADER_NAMES[:put], ActiveResource::Connection::HTTP_FORMAT_HEADER_NAMES[:post]]
-    headers_names.each{ |name| assert_equal 'Content-Type', name }
+    [:patch, :put, :post].each do |verb|
+      header_name = ActiveResource::Connection::HTTP_FORMAT_HEADER_NAMES[verb]
+      assert_equal 'Content-Type', header_name
+    end
   end
 
   def test_formats_on_single_element
diff --git a/activeresource/test/cases/http_mock_test.rb b/activeresource/test/cases/http_mock_test.rb
index d2fd911314..d13d9258ce 100644
--- a/activeresource/test/cases/http_mock_test.rb
+++ b/activeresource/test/cases/http_mock_test.rb
@@ -8,7 +8,7 @@ class HttpMockTest < ActiveSupport::TestCase
 
   FORMAT_HEADER = ActiveResource::Connection::HTTP_FORMAT_HEADER_NAMES
 
-  [:post, :put, :get, :delete, :head].each do |method|
+  [:post, :patch, :put, :get, :delete, :head].each do |method|
     test "responds to simple #{method} request" do
       ActiveResource::HttpMock.respond_to do |mock|
         mock.send(method, "/people/1", { FORMAT_HEADER[method] => "application/json" }, "Response")
@@ -193,7 +193,7 @@ class HttpMockTest < ActiveSupport::TestCase
   end
 
   def request(method, path, headers = {}, body = nil)
-    if method.in?([:put, :post])
+    if method.in?([:patch, :put, :post])
       @http.send(method, path, body, headers)
     else
       @http.send(method, path, headers)