[WEBSITE-878] Implementation to add headers to a request

* Headers can be added on initialization of Request object.
* Default header set.
* Added documentation both in line (for yard) and in the readme.

README.md

@@ -98,7 +98,19 @@ parliament.parties('123').people.current
 parliament.people('123').letters('456')
 ```
 
+### Setting headers
 
+#### Setting headers 'globally'
+Within the code you can set global headers using the following snippet.
+```
+Parliament::Request.headers = { 'Accept' => 'Test' }
+
+# The headers should be set for all new objects
+Parliament::Request.new.headers #=> { 'Accept' => 'Test' }
+
+# You can still override the headers on an instance by instance basis
+Parliament::Request.new(headers: { 'Accept' => 'Test2' }).headers #=> { 'Accept' => 'Test2' }
+```
 ### Methods
 [parliament-ruby][parliament-ruby] comes with the following common methods:
 

lib/parliament/request.rb

@@ -5,14 +5,15 @@ module Parliament
   # @since 0.1.0
   #
   # @attr_reader [String] base_url the base url of our api. (expected: http://example.com - without the trailing slash).
+  # @attr_reader [Hash] headers the headers being sent in the request.
   class Request
-    attr_reader :base_url
+    attr_reader :base_url, :headers
 
     # Creates a new instance of Parliament::Request.
     #
     # An interesting note for #initialize is that setting base_url on the class, or using the environment variable
     # PARLIAMENT_BASE_URL means you don't need to pass in a base_url. You can pass one anyway to override the
-    # environment variable or class parameter.
+    # environment variable or class parameter.  Similarly, headers can be set by either settings the headers on the class, or passing headers in.
     #
     # @example Setting the base_url on the class
     #   Parliament::Request.base_url = 'http://example.com'
@@ -35,10 +36,27 @@ class Request
     #
     #   Parliament::Request.new(base_url: 'http://example.com').base_url #=> 'http://example.com'
     #
+    # @example Setting the headers on the class
+    #   Parliament::Request.headers = { 'Accept' => 'Test' }
+    #
+    #   Parliament::Request.new.headers #=> '{ 'Accept' => 'Test' }
+    #
+    # @example Setting the headers via a parameter
+    #   Parliament::Request.headers #=> nil
+    #
+    #   Parliament::Request.new(headers: '{ 'Accept' => 'Test' }).headers #=> { 'Accept' => 'Test' }
+    #
+    # @example Overriding the headers via a parameter
+    #   Parliament::Request.headers = { 'Accept' => 'Test' }
+    #
+    #   Parliament::Request.new(headers: '{ 'Accept' => 'Test2' }).headers #=> { 'Accept' => 'Test2' }
+    #
     # @param [String] base_url the base url of our api. (expected: http://example.com - without the trailing slash).
-    def initialize(base_url: nil)
+    # @param [Hash] headers the headers being sent in the request.
+    def initialize(base_url: nil, headers: nil)
       @endpoint_parts = []
       @base_url = base_url || self.class.base_url || ENV['PARLIAMENT_BASE_URL']
+      @headers = headers || self.class.headers || {}
     end
 
     # Overrides ruby's method_missing to allow creation of URLs through method calls.
@@ -113,7 +131,7 @@ def get(params: nil)
 
       net_response = http.start do |h|
         api_request = Net::HTTP::Get.new(endpoint_uri.request_uri)
-        api_request.add_field('Accept', 'application/n-triples')
+        add_headers(api_request)
 
         h.request api_request
       end
@@ -126,8 +144,20 @@ def get(params: nil)
     private
 
     # @attr [String] base_url the base url of our api. (expected: http://example.com - without the trailing slash).
+    # @attr [Hash] headers the headers being sent in the request.
     class << self
-      attr_accessor :base_url
+      attr_accessor :base_url, :headers
+    end
+
+    def default_headers
+      { 'Accept' => 'application/n-triples' }
+    end
+
+    def add_headers(request)
+      headers = default_headers.merge(@headers)
+      headers.each do |key, value|
+        request.add_field(key, value)
+      end
     end
 
     def api_endpoint

lib/parliament/version.rb

@@ -1,3 +1,3 @@
 module Parliament
-  VERSION = '0.6.2'.freeze
+  VERSION = '0.6.3'.freeze
 end

spec/parliament/request_spec.rb

@@ -121,6 +121,23 @@
         expect(subject.size).to eq(1)
       end
     end
+
+    context 'it accepts headers' do
+      it 'sets the header correctly when passed in' do
+        Parliament::Request.headers = { 'Access-Token'=>'Test-Token' }
+        Parliament::Request.new(base_url: 'http://localhost:3030').people.get
+
+        expect(WebMock).to have_requested(:get, 'http://localhost:3030/people').
+            with(:headers => {'Accept'=>['*/*', 'application/n-triples'], 'Accept-Encoding'=>'gzip;q=1.0,deflate;q=0.6,identity;q=0.3', 'Access-Token'=>'Test-Token', 'User-Agent'=>'Ruby'}).once
+      end
+
+      it 'sets the default headers only when no additional headers passed' do
+        Parliament::Request.new(base_url: 'http://localhost:3030').people.get
+
+        expect(WebMock).to have_requested(:get, 'http://localhost:3030/people').
+            with(:headers => {'Accept'=>['*/*', 'application/n-triples'], 'Accept-Encoding'=>'gzip;q=1.0,deflate;q=0.6,identity;q=0.3', 'User-Agent'=>'Ruby'}).once
+      end
+    end
   end
 
   describe '#assign_decorator' do