Add body and headers to request.active_resource

Closes rails#391

Expand the data broadcast by the `request.active_resource` Active
Support Notification instrumentation event.

For `GET` and `OPTION` requests, omit the `:body` value from the
payload. For all other requests, include the `:body`.

README.md

@@ -296,6 +296,8 @@ The `payload` is a `Hash` with the following keys:
 
 * `method` as a `Symbol`
 * `request_uri` as a `String`
+* `headers` as a `Hash`
+* `body` as a `String` when available
 * `result` as an `Net::HTTPResponse`
 
 ## License

lib/active_resource/connection.rb

@@ -116,9 +116,13 @@ def head(path, headers = {})
     private
       # Makes a request to the remote service.
       def request(method, path, *arguments)
+        body, headers = arguments
+        headers, body = body, nil if headers.nil?
         result = ActiveSupport::Notifications.instrument("request.active_resource") do |payload|
           payload[:method]      = method
           payload[:request_uri] = "#{site.scheme}://#{site.host}:#{site.port}#{path}"
+          payload[:headers]     = headers
+          payload[:body]        = body
           payload[:result]      = http.send(method, path, *arguments)
         end
         handle_response(result)

test/cases/notifications_test.rb

@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+require "abstract_unit"
+require "fixtures/person"
+
+class NotificationsTest < ActiveSupport::TestCase
+  def setup
+    matz  = { person: { id: 1, name: "Matz" } }
+    @people = { people: [ matz ] }.to_json
+    @default_request_headers = { "Content-Type" => "application/json" }
+
+    ActiveResource::HttpMock.respond_to do |mock|
+      mock.get  "/people.json?name=Matz", { "Accept" => "application/json" }, @people
+      mock.post "/people.json", { "Content-Type" => "application/json" }, nil, 201, "Location" => "/people/5.json"
+    end
+  end
+
+  def test_get_request_with_params
+    payload = capture_notifications { Person.where(name: "Matz") }
+
+    assert_equal :get, payload[:method]
+    assert_equal "http://37s.sunrise.i:3000/people.json?name=Matz", payload[:request_uri]
+    assert_equal({ "Accept" => "application/json" }, payload[:headers])
+    assert_nil payload[:body]
+    assert_kind_of ActiveResource::Response, payload[:result]
+  end
+
+  def test_post_request_with_body
+    payload = capture_notifications { Person.create!(name: "Matz") }
+
+    assert_equal :post, payload[:method]
+    assert_equal "http://37s.sunrise.i:3000/people.json", payload[:request_uri]
+    assert_equal({ "Content-Type" => "application/json" }, payload[:headers])
+    assert_equal({ "person" => { "name" => "Matz" } }.to_json, payload[:body])
+    assert_kind_of ActiveResource::Response, payload[:result]
+  end
+
+  def capture_notifications(&block)
+    payload = nil
+    ActiveSupport::Notifications.subscribed ->(event) { payload = event.payload }, "request.active_resource", &block
+    payload
+  end
+end