Fix collection successive iterations when there are multiple pages (#581)

Co-authored-by: João Coelho <joaocoelho@nutrium.io>
Co-authored-by: Sean Healy <sean.healy@intercom.io>

Author: 3 people

lib/intercom/base_collection_proxy.rb

@@ -58,6 +58,7 @@ def has_next_link?(response_hash)
         @params[:starting_after] = paging_next['starting_after']
         return true
       else
+        @params[:starting_after] = nil
         return false
       end
     end

spec/unit/intercom/base_collection_proxy_spec.rb

@@ -4,7 +4,7 @@
   let(:client) { Intercom::Client.new(token: 'token') }
 
   it "stops iterating if no starting after value" do
-    client.expects(:get).with("/contacts", {}). returns(page_of_contacts(false))
+    client.expects(:get).with("/contacts", {}).returns(page_of_contacts(false))
     emails = []
     client.contacts.all.each { |contact| emails << contact.email }
     _(emails).must_equal %w[test1@example.com test2@example.com test3@example.com]
@@ -15,6 +15,7 @@
     client.expects(:get).with('/contacts', { starting_after: "EnCrYpTeDsTrInG" }).returns(page_of_contacts(false))
     emails = []
     client.contacts.all.each { |contact| emails << contact.email }
+    _(emails).must_equal %w[test1@example.com test2@example.com test3@example.com test1@example.com test2@example.com test3@example.com]
   end
 
   it "supports indexed array access" do
@@ -27,4 +28,20 @@
     emails = client.contacts.all.map { |contact| contact.email }
     _(emails).must_equal %w[test1@example.com test2@example.com test3@example.com]
   end
+
+  it "keeps entire collection iterable after first iteration" do
+    contacts = client.contacts.all
+    emails_iter1 = []
+    emails_iter2 = []
+    expects_pagination = proc do
+      client.expects(:get).with("/contacts", {}).returns(page_of_contacts(true))
+      client.expects(:get).with("/contacts", { starting_after: "EnCrYpTeDsTrInG" }).returns(page_of_contacts(false))
+    end
+
+    expects_pagination.call
+    contacts.each { |contact| emails_iter1 << contact.email }
+    expects_pagination.call
+    contacts.each { |contact| emails_iter2 << contact.email }
+    _(emails_iter1).must_equal emails_iter2
+  end
 end