feat: paginate pacticipant versions

Closes: #355

lib/pact_broker/api/decorators/decorator_context.rb

@@ -2,14 +2,14 @@ module PactBroker
   module Api
     module Decorators
       class DecoratorContext < Hash
-
-        attr_reader :base_url, :resource_url, :resource_title, :env
+        attr_reader :base_url, :resource_url, :resource_title, :env, :query_string
 
         def initialize base_url, resource_url, env, options = {}
           @base_url = self[:base_url] = base_url
           @resource_url = self[:resource_url] = resource_url
           @resource_title = self[:resource_title] = options[:resource_title]
           @env = self[:env] = env
+          @query_string = self[:query_string] = (env['QUERY_STRING'] && !env['QUERY_STRING'].empty? ? env['QUERY_STRING'] : nil)
           merge!(options)
         end
 

lib/pact_broker/api/decorators/pagination_links.rb

@@ -0,0 +1,34 @@
+require 'roar/decorator'
+require 'roar/json/hal'
+
+module PactBroker
+  module Api
+    module Decorators
+      module PaginationLinks
+        include Roar::JSON::HAL
+        include Roar::JSON::HAL::Links
+
+        link :next do | context |
+          if represented.respond_to?(:current_page) &&
+              represented.respond_to?(:page_count) &&
+              represented.current_page < represented.page_count
+            {
+              href: context[:resource_url] + "?pageSize=#{represented.page_size}&pageNumber=#{represented.current_page + 1}",
+              title: "Next page"
+            }
+
+          end
+        end
+
+        link :previous do | context |
+          if represented.respond_to?(:first_page?) && !represented.first_page?
+            {
+              href: context[:resource_url] + "?pageSize=#{represented.page_size}&pageNumber=#{represented.current_page - 1}",
+              title: "Previous page"
+            }
+          end
+        end
+      end
+    end
+  end
+end

lib/pact_broker/api/decorators/versions_decorator.rb

@@ -1,5 +1,6 @@
 require_relative 'base_decorator'
 require_relative 'version_decorator'
+require_relative 'pagination_links'
 
 module PactBroker
   module Api
@@ -9,12 +10,15 @@ class VersionsDecorator < BaseDecorator
         collection :entries, as: :versions, embedded: true, :extend => PactBroker::Api::Decorators::VersionDecorator
 
         link :self do | context |
+          href = append_query_if_present(context[:resource_url], context[:query_string])
           {
-            href: context[:resource_url],
+            href: href,
             title: "All application versions of #{context[:pacticipant_name]}"
           }
         end
 
+        include PaginationLinks
+
         link :'pb:pacticipant' do | context |
           {
             href: pacticipant_url(context[:base_url], OpenStruct.new(name: context[:pacticipant_name])),

lib/pact_broker/api/pact_broker_urls.rb

@@ -307,6 +307,14 @@ def url_encode param
         ERB::Util.url_encode param
       end
 
+      def append_query_if_present(url, query)
+        if query && query.size > 0
+          url + "?#{query}"
+        else
+          url
+        end
+      end
+
       private
 
       def representable_pact pact

lib/pact_broker/api/resources/versions.rb

@@ -23,12 +23,23 @@ def to_json
         end
 
         def versions
-          @versions ||= pacticipant_service.find_all_pacticipant_versions_in_reverse_order pacticipant_name
+          @versions ||= pacticipant_service.find_all_pacticipant_versions_in_reverse_order(pacticipant_name, pagination_options)
         end
 
         def policy_name
           :'versions::versions'
         end
+
+        def pagination_options
+          if request.query['pageNumber'] || request.query['pageSize']
+            {
+              page_number: request.query['pageNumber']&.to_i || 1,
+              page_size: request.query['pageSize']&.to_i || 100
+            }
+          else
+            nil
+          end
+        end
       end
     end
   end

lib/pact_broker/doc/views/pacticipant/versions.markdown

@@ -0,0 +1,9 @@
+# Pacticipant versions
+
+Allowed methods: `GET`
+
+Path: `/pacticipants/{pacticipant}/versions`
+
+A list of pacticipant versions in order from newest to oldest.
+
+To paginate, append `?pageNumber=x&pageSize=x` and follow the `next` relation until it is no longer present.

lib/pact_broker/pacticipants/repository.rb

@@ -8,6 +8,7 @@ module Pacticipants
     class Repository
 
       include PactBroker::Repositories::Helpers
+      include PactBroker::Repositories
 
       def find_by_name name
         pacticipants = PactBroker::Domain::Pacticipant.where(name_like(:name, name)).all
@@ -35,11 +36,11 @@ def find options = {}
         query.order_ignore_case(Sequel[:pacticipants][:name]).eager(:labels).eager(:latest_version).all
       end
 
-      def find_all_pacticipant_versions_in_reverse_order name
-        PactBroker::Domain::Version.select_all_qualified
-          .join(:pacticipants, {id: :pacticipant_id})
-          .where(name_like(:name, name))
-          .reverse_order(:order)
+      def find_all_pacticipant_versions_in_reverse_order name, pagination_options = nil
+        pacticipant = pacticipant_repository.find_by_name!(name)
+        query = PactBroker::Domain::Version.where(pacticipant: pacticipant).reverse_order(:order)
+        query = query.paginate(pagination_options[:page_number], pagination_options[:page_size]) if pagination_options
+        query
       end
 
       def find_by_name_or_create name

lib/pact_broker/pacticipants/service.rb

@@ -52,8 +52,8 @@ def self.find options
         pacticipant_repository.find options
       end
 
-      def self.find_all_pacticipant_versions_in_reverse_order name
-        pacticipant_repository.find_all_pacticipant_versions_in_reverse_order(name)
+      def self.find_all_pacticipant_versions_in_reverse_order name, pagination_options = nil
+        pacticipant_repository.find_all_pacticipant_versions_in_reverse_order(name, pagination_options)
       end
 
       def self.find_pacticipant_repository_url_by_pacticipant_name name

spec/features/get_versions_spec.rb

@@ -21,6 +21,14 @@
     it "returns a list of links to the versions" do
       expect(last_response_body[:_links][:"versions"].size).to eq 2
     end
+
+    context "with pagination options" do
+      subject { get(path, { 'pageSize' => '1', 'pageNumber' => '1' }) }
+
+      it "paginates the response" do
+        expect(last_response_body[:_links][:"versions"].size).to eq 1
+      end
+    end
   end
 
   context "when the pacticipant does not exist" do

spec/lib/pact_broker/api/decorators/versions_decorator_spec.rb

@@ -3,32 +3,38 @@
 require 'pact_broker/domain/version'
 
 module PactBroker
-
   module Api
-
     module Decorators
-
       describe VersionsDecorator do
 
-        let(:options) { {base_url: 'http://example.org', pacticipant_name: "Consumer" }}
+        let(:options) { { resource_url: 'http://versions', base_url: 'http://example.org', pacticipant_name: "Consumer", query_string: query_string}}
+        let(:query_string) { nil }
+        let(:versions) { [] }
 
         subject { JSON.parse VersionsDecorator.new(versions).to_json(user_options: options), symbolize_names: true }
 
-        context "with no versions" do
-          let(:versions) { [] }
+        context "with no query string" do
+          its([:_links, :self, :href]) { is_expected.to eq 'http://versions' }
+        end
 
+        context "with a query string" do
+          let(:query_string) { 'foo=bar' }
+          its([:_links, :self, :href]) { is_expected.to eq 'http://versions?foo=bar' }
+        end
+
+        context "with no versions" do
           it "doesn't blow up" do
             subject
           end
         end
 
         context "with versions" do
-          let(:version) do
+          let!(:version) do
             TestDataBuilder.new
               .create_consumer("Consumer")
               .create_consumer_version("1.2.3")
               .create_consumer_version_tag("prod")
-            PactBroker::Versions::Repository.new.find_by_pacticipant_name_and_number "Consumer", "1.2.3"
+              .and_return(:consumer_version)
           end
           let(:versions) { [version] }
 
@@ -37,7 +43,6 @@ module Decorators
             expect(subject[:_embedded][:versions].size).to eq 1
           end
         end
-
       end
     end
   end

spec/lib/pact_broker/pacticipants/repository_spec.rb

@@ -154,8 +154,15 @@ module Pacticipants
         it "returns all the application versions for the given consumer" do
           expect(subject.collect(&:number)).to eq ["4.5.6", "1.2.3"]
         end
-      end
 
+        context "with pagination options" do
+          subject { Repository.new.find_all_pacticipant_versions_in_reverse_order "Foo", page_number: 1, page_size: 1 }
+
+          it "paginates the query" do
+            expect(subject.collect(&:number)).to eq ["4.5.6"]
+          end
+        end
+      end
     end
   end
 end