Add http options

This makes it possible to configure the underlying net/http connections
for things like timeouts, proxies, and SSL certificate settings.

lib/nexmo.rb

@@ -1,6 +1,7 @@
 require 'nexmo/version'
 require 'nexmo/params'
 require 'nexmo/form_data'
+require 'nexmo/http'
 require 'nexmo/json'
 require 'nexmo/jwt'
 require 'nexmo/signature'

lib/nexmo/client.rb

@@ -25,9 +25,17 @@ def initialize(options = {})
 
       @user_agent = UserAgent.string(options[:app_name], options[:app_version])
 
+      self.http_options = options[:http]
+
       self.logger = options[:logger] || (defined?(Rails.logger) && Rails.logger)
     end
 
+    attr_reader :http_options
+
+    def http_options=(hash)
+      @http_options = HTTP::Options.new(hash)
+    end
+
     def logger
       @logger
     end

lib/nexmo/http.rb

@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+require 'net/http'
+
+module Nexmo
+  module HTTP # :nodoc:
+    class Options
+      def initialize(hash)
+        @hash = hash || {}
+
+        @hash.each_key do |name|
+          next if defined_options.key?(name)
+
+          raise ArgumentError, "#{name.inspect} is not a valid option"
+        end
+      end
+
+      def set(http)
+        @hash.each do |name, value|
+          http.public_send(defined_options.fetch(name), value)
+        end
+      end
+
+      private
+
+      def defined_options
+        @defined_options ||= Net::HTTP.instance_methods.grep(/\w=\z/).each_with_object({}) do |name, hash|
+          hash[name.to_s.chomp('=').to_sym] = name
+        end
+      end
+    end
+  end
+end

lib/nexmo/namespace.rb

@@ -11,8 +11,10 @@ def initialize(client)
 
       @host = self.class.host
 
-      @http = Net::HTTP.new(@host, Net::HTTP.https_default_port)
+      @http = Net::HTTP.new(@host, Net::HTTP.https_default_port, p_addr = nil)
       @http.use_ssl = true
+
+      @client.http_options.set(@http)
     end
 
     def self.host

test/nexmo/http_options_test.rb

@@ -0,0 +1,35 @@
+require 'minitest/autorun'
+require 'nexmo/http'
+
+class NexmoHTTPOptionsTest < Minitest::Test
+  def read_timeout
+    5
+  end
+
+  def proxy_address
+    'localhost'
+  end
+
+  def ca_file
+    'cert.pem'
+  end
+
+  def test_invalid_option_raises_argument_error
+    exception = assert_raises(ArgumentError) { Nexmo::HTTP::Options.new(foo_timeout: 1) }
+
+    assert_includes exception.message, ':foo_timeout is not a valid option'
+  end
+
+  def test_set_method
+    http = Net::HTTP.new('example.com', Net::HTTP.https_default_port, p_addr = nil)
+
+    hash = {read_timeout: read_timeout, proxy_address: proxy_address, ca_file: ca_file}
+
+    options = Nexmo::HTTP::Options.new(hash)
+    options.set(http)
+
+    assert_equal read_timeout, http.read_timeout
+    assert_equal proxy_address, http.proxy_address
+    assert_equal ca_file, http.ca_file
+  end
+end