Adding scroll API feature

Author: choran

lib/intercom/api_operations/scroll.rb

@@ -0,0 +1,16 @@
+require 'intercom/scroll_collection_proxy'
+
+module Intercom
+  module ApiOperations
+    module Scroll
+
+      def scroll()
+        collection_name = Utils.resource_class_to_collection_name(collection_class)
+        finder_details = {}
+        finder_details[:url] = "/#{collection_name}"
+        ScrollCollectionProxy.new(collection_name, finder_details: finder_details,  client: @client)
+      end
+
+    end
+  end
+end

lib/intercom/scroll_collection_proxy.rb

@@ -0,0 +1,83 @@
+require "intercom/utils"
+require "ext/sliceable_hash"
+
+module Intercom
+  class ScrollCollectionProxy
+
+    attr_reader :resource_name, :scroll_url, :resource_class, :scroll_param, :records
+
+    def initialize(resource_name, finder_details: {}, client:)
+      @resource_name = resource_name
+      @resource_class = Utils.constantize_resource_name(resource_name)
+      @scroll_url = (finder_details[:url] || "/#{@resource_name}") + '/scroll'
+      @client = client
+
+    end
+
+    def next(scroll_parameter=nil)
+      @records = []
+      if not scroll_parameter
+        #First time so do initial get without scroll_param
+        response_hash = @client.get(@scroll_url, '')
+      else
+        #Not first call so use get next page
+        response_hash = @client.get(@scroll_url, scroll_param: scroll_parameter)
+      end
+      raise Intercom::HttpError.new('Http Error - No response entity returned') unless response_hash
+      @scroll_param = extract_scroll_param(response_hash)
+      top_level_entity_key = deserialize_response_hash(response_hash)
+      response_hash[top_level_entity_key] = response_hash[top_level_entity_key].map do |object_json|
+        Lib::TypedJsonDeserializer.new(object_json).deserialize
+      end
+      @records = response_hash[@resource_name]
+      self
+    end
+
+    def each(&block)
+      scroll_param = nil
+      loop do
+        if not scroll_param
+          response_hash = @client.get(@scroll_url, '')
+        else
+          response_hash = @client.get(@scroll_url, scroll_param: scroll_param)
+        end
+        raise Intercom::HttpError.new('Http Error - No response entity returned') unless response_hash
+        response_hash[deserialize_response_hash(response_hash)].each do |object_json|
+          block.call Lib::TypedJsonDeserializer.new(object_json).deserialize
+        end
+        scroll_param = extract_scroll_param(response_hash)
+        break if not records_present?(response_hash)
+      end
+      self
+    end
+
+    def [](target_index)
+      self.each_with_index do |item, index|
+        return item if index == target_index
+      end
+      nil
+    end
+
+    include Enumerable
+
+    private
+
+    def deserialize_response_hash(response_hash)
+      top_level_type = response_hash.delete('type')
+      if resource_name == 'subscriptions'
+        top_level_entity_key = 'items'
+      else
+        top_level_entity_key = Utils.entity_key_from_type(top_level_type)
+      end
+    end
+
+    def records_present?(response_hash)
+      (response_hash[@resource_name].length > 0)
+    end
+
+    def extract_scroll_param(response_hash)
+      return nil unless records_present?(response_hash)
+      response_hash['scroll_param']
+    end
+  end
+end

lib/intercom/service/user.rb

@@ -1,6 +1,7 @@
 require 'intercom/service/base_service'
 require 'intercom/api_operations/load'
 require 'intercom/api_operations/list'
+require 'intercom/api_operations/scroll'
 require 'intercom/api_operations/find'
 require 'intercom/api_operations/find_all'
 require 'intercom/api_operations/save'
@@ -14,6 +15,7 @@ module Service
     class User < BaseService
       include ApiOperations::Load
       include ApiOperations::List
+      include ApiOperations::Scroll
       include ApiOperations::Find
       include ApiOperations::FindAll
       include ApiOperations::Save

spec/spec_helper.rb

@@ -216,6 +216,14 @@ def page_of_users(include_next_link= false)
   }
 end
 
+def users_scroll(include_users= false)
+  {
+      "type"=>"user.list",
+      "scroll_param"=> ("da6bbbac-25f6-4f07-866b-b911082d7"),
+      "users"=> (include_users ? [test_user("[email protected]"), test_user("[email protected]"), test_user("[email protected]")] : []),
+  }
+end
+
 def users_pagination(include_next_link=false, per_page=0, page=0, total_pages=0, total_count=0, user_list=[])
   {
       "type"=>"user.list",

spec/unit/intercom/scroll_collection_proxy_spec.rb

@@ -0,0 +1,56 @@
+require "spec_helper"
+
+describe Intercom::ScrollCollectionProxy do
+  let (:client) { Intercom::Client.new(app_id: 'app_id',  api_key: 'api_key') }
+
+  it "stops iterating if no users returned" do
+    client.expects(:get).with("/users/scroll", '').returns(users_scroll(false))
+    emails = []
+    client.users.scroll.each { |user| emails << user.email }
+    emails.must_equal %W()
+  end
+
+  it "keeps iterating if users returned" do
+    client.expects(:get).with("/users/scroll", '').returns(users_scroll(true))
+    client.expects(:get).with('/users/scroll', {:scroll_param => 'da6bbbac-25f6-4f07-866b-b911082d7'}).returns(users_scroll(false))
+    emails = []
+    client.users.scroll.each { |user| emails << user.email }
+  end
+
+  it "supports indexed array access" do
+    client.expects(:get).with("/users/scroll", '').returns(users_scroll(true))
+    client.users.scroll[0].email.must_equal '[email protected]'
+  end
+
+  it "supports map" do
+    client.expects(:get).with("/users/scroll", '').returns(users_scroll(true))
+    client.expects(:get).with('/users/scroll', {:scroll_param => 'da6bbbac-25f6-4f07-866b-b911082d7'}).returns(users_scroll(false))
+    emails = client.users.scroll.map { |user| user.email }
+    emails.must_equal %W([email protected] [email protected] [email protected])
+  end
+
+  it "returns one page scroll" do
+    client.expects(:get).with("/users/scroll", '').returns(users_scroll(true))
+    scroll = client.users.scroll.next
+    emails = []
+    scroll.records.each {|usr| emails << usr.email}
+    emails.must_equal %W([email protected] [email protected] [email protected])
+  end
+
+  it "keeps iterating if called with scroll_param" do
+    client.expects(:get).with("/users/scroll", '').returns(users_scroll(true))
+    client.expects(:get).with('/users/scroll', {:scroll_param => 'da6bbbac-25f6-4f07-866b-b911082d7'}).returns(users_scroll(true))
+    scroll = client.users.scroll.next
+    scroll = client.users.scroll.next('da6bbbac-25f6-4f07-866b-b911082d7')
+    emails =[]
+    scroll.records.each {|usr| puts usr.email}
+  end
+
+  it "works with an empty list" do
+    client.expects(:get).with("/users/scroll", '').returns(users_scroll(false))
+    scroll = client.users.scroll.next
+    emails = []
+    scroll.records.each {|usr| emails << usr.email}
+    emails.must_equal %W()
+  end
+end