Merge pull request #35 from hyperoslo/feature/welcome-messages

Implement welcome messages

README.md

@@ -155,6 +155,14 @@ Bot.on :delivery do |delivery|
 end
 ```
 
+#### Set a welcome message
+
+You can greet new humans to entice them into talking to you:
+
+```ruby
+Facebook::Messenger::Welcome.set text: 'Hello, human!'
+```
+
 ## Configuration
 
 ### Create an Application on Facebook

lib/facebook/messenger.rb

@@ -1,6 +1,7 @@
 require 'facebook/messenger/version'
 require 'facebook/messenger/error'
 require 'facebook/messenger/subscriptions'
+require 'facebook/messenger/welcome'
 require 'facebook/messenger/bot'
 require 'facebook/messenger/server'
 require 'facebook/messenger/configuration'

lib/facebook/messenger/welcome.rb

@@ -0,0 +1,61 @@
+require 'httparty'
+
+module Facebook
+  module Messenger
+    # This module handles setting welcome messages.
+    #
+    # https://developers.facebook.com/docs/messenger-platform/send-api-reference#welcome_message_configuration
+    module Welcome
+      include HTTParty
+
+      base_uri 'https://graph.facebook.com/v2.6/me'
+
+      format :json
+
+      module_function
+
+      def set(message)
+        response = post '/thread_settings',
+                        body: welcome_setting_for(message).to_json
+
+        raise_errors(response)
+
+        true
+      end
+
+      def unset
+        response = post '/thread_settings',
+                        body: welcome_setting_for(nil).to_json
+
+        raise_errors(response)
+
+        true
+      end
+
+      def raise_errors(response)
+        raise Error, response['error']['message'] if response.key? 'error'
+      end
+
+      def default_options
+        super.merge(
+          query: {
+            access_token: Facebook::Messenger.config.access_token
+          },
+          headers: {
+            'Content-Type' => 'application/json'
+          }
+        )
+      end
+
+      def welcome_setting_for(payload)
+        {
+          setting_type: 'call_to_actions',
+          thread_state: 'new_thread',
+          call_to_actions: payload ? [{ message: payload }] : []
+        }
+      end
+
+      class Error < Facebook::Messenger::Error; end
+    end
+  end
+end

spec/facebook/messenger/welcome_spec.rb

@@ -0,0 +1,139 @@
+require 'spec_helper'
+
+describe Facebook::Messenger::Welcome do
+  let(:access_token) { '<access token>' }
+
+  let(:thread_settings_url) do
+    Facebook::Messenger::Welcome.base_uri + '/thread_settings'
+  end
+
+  before do
+    Facebook::Messenger.configure do |config|
+      config.access_token = access_token
+    end
+  end
+
+  describe '.set' do
+    context 'with a successful response' do
+      before do
+        stub_request(:post, thread_settings_url)
+          .with(
+            query: {
+              access_token: access_token
+            },
+            headers: {
+              'Content-Type' => 'application/json'
+            },
+            body: JSON.dump(
+              setting_type: 'call_to_actions',
+              thread_state: 'new_thread',
+              call_to_actions: [
+                {
+                  message: {
+                    text: 'Hello, human!'
+                  }
+                }
+              ]
+            )
+          )
+          .to_return(
+            body: JSON.dump(
+              result: "Successfully added new thread's CTAs"
+            ),
+            status: 200,
+            headers: default_graph_api_response_headers
+          )
+      end
+
+      it 'returns true' do
+        expect(subject.set(text: 'Hello, human!')).to be(true)
+      end
+    end
+
+    context 'with an unsuccessful response' do
+      let(:error_message) { 'Invalid OAuth access token.' }
+
+      before do
+        stub_request(:post, thread_settings_url)
+          .with(query: { access_token: access_token })
+          .to_return(
+            body: JSON.dump(
+              'error' => {
+                'message' => error_message,
+                'type' => 'OAuthException',
+                'code' => 190,
+                'fbtrace_id' => 'Hlssg2aiVlN'
+              }
+            ),
+            status: 200,
+            headers: default_graph_api_response_headers
+          )
+      end
+
+      it 'raises an error' do
+        expect { subject.set text: 'Hello, human!' }.to raise_error(
+          Facebook::Messenger::Welcome::Error, error_message
+        )
+      end
+    end
+  end
+
+  describe '.unset' do
+    context 'with a successful response' do
+      before do
+        stub_request(:post, thread_settings_url)
+          .with(
+            query: {
+              access_token: access_token
+            },
+            headers: {
+              'Content-Type' => 'application/json'
+            },
+            body: JSON.dump(
+              setting_type: 'call_to_actions',
+              thread_state: 'new_thread',
+              call_to_actions: []
+            )
+          )
+          .to_return(
+            body: JSON.dump(
+              result: "Successfully added new thread's CTAs"
+            ),
+            status: 200,
+            headers: default_graph_api_response_headers
+          )
+      end
+
+      it 'returns true' do
+        expect(subject.unset).to be(true)
+      end
+    end
+
+    context 'with an unsuccessful response' do
+      let(:error_message) { 'Invalid OAuth access token.' }
+
+      before do
+        stub_request(:post, thread_settings_url)
+          .with(query: { access_token: access_token })
+          .to_return(
+            body: JSON.dump(
+              'error' => {
+                'message' => error_message,
+                'type' => 'OAuthException',
+                'code' => 190,
+                'fbtrace_id' => 'Hlssg2aiVlN'
+              }
+            ),
+            status: 200,
+            headers: default_graph_api_response_headers
+          )
+      end
+
+      it 'raises an error' do
+        expect { subject.unset }.to raise_error(
+          Facebook::Messenger::Welcome::Error, error_message
+        )
+      end
+    end
+  end
+end