Merge branch 'feature/gb/paginated-environments-api' into 'master'

Expose paginated environments list API endpoint

See merge request !8928

9 files changed, 282 insertions, 34 deletions

diff --git a/app/models/ci/build.rb b/app/models/ci/build.rb
index 5213ea9d02b..8c1b076c2d7 100644
--- a/app/models/ci/build.rb
+++ b/app/models/ci/build.rb
@@ -20,7 +20,7 @@ module Ci
     end
 
     serialize :options
-    serialize :yaml_variables, Gitlab::Serialize::Ci::Variables
+    serialize :yaml_variables, Gitlab::Serializer::Ci::Variables
 
     validates :coverage, numericality: true, allow_blank: true
     validates_presence_of :ref
diff --git a/app/serializers/environment_serializer.rb b/app/serializers/environment_serializer.rb
index 91955542f25..fe16a3784c4 100644
--- a/app/serializers/environment_serializer.rb
+++ b/app/serializers/environment_serializer.rb
@@ -1,3 +1,50 @@
 class EnvironmentSerializer < BaseSerializer
+  Item = Struct.new(:name, :size, :latest)
+
   entity EnvironmentEntity
+
+  def within_folders
+    tap { @itemize = true }
+  end
+
+  def with_pagination(request, response)
+    tap { @paginator = Gitlab::Serializer::Pagination.new(request, response) }
+  end
+
+  def itemized?
+    @itemize
+  end
+
+  def paginated?
+    @paginator.present?
+  end
+
+  def represent(resource, opts = {})
+    resource = @paginator.paginate(resource) if paginated?
+
+    if itemized?
+      itemize(resource).map do |item|
+        { name: item.name,
+          size: item.size,
+          latest: super(item.latest, opts) }
+      end
+    else
+      super(resource, opts)
+    end
+  end
+
+  private
+
+  def itemize(resource)
+    items = resource.group(:item_name).order('item_name ASC')
+      .pluck('COALESCE(environment_type, name) AS item_name',
+             'COUNT(*) AS environments_count',
+             'MAX(id) AS last_environment_id')
+
+    environments = resource.where(id: items.map(&:last)).index_by(&:id)
+
+    items.map do |name, size, id|
+      Item.new(name, size, environments[id])
+    end
+  end
 end
diff --git a/app/serializers/pipeline_serializer.rb b/app/serializers/pipeline_serializer.rb
index b2de6c5832e..2bc6cf3266e 100644
--- a/app/serializers/pipeline_serializer.rb
+++ b/app/serializers/pipeline_serializer.rb
@@ -1,41 +1,25 @@
 class PipelineSerializer < BaseSerializer
   class InvalidResourceError < StandardError; end
-  include API::Helpers::Pagination
-  Struct.new('Pagination', :request, :response)
 
   entity PipelineEntity
 
-  def represent(resource, opts = {})
-    if paginated?
-      raise InvalidResourceError unless resource.respond_to?(:page)
-
-      super(paginate(resource.includes(project: :namespace)), opts)
-    else
-      super(resource, opts)
-    end
-  end
-
-  def paginated?
-    defined?(@pagination)
-  end
-
   def with_pagination(request, response)
-    tap { @pagination = Struct::Pagination.new(request, response) }
+    tap { @paginator = Gitlab::Serializer::Pagination.new(request, response) }
   end
 
-  private
-
-  # Methods needed by `API::Helpers::Pagination`
-  #
-  def params
-    @pagination.request.query_parameters
+  def paginated?
+    @paginator.present?
   end
 
-  def request
-    @pagination.request
-  end
+  def represent(resource, opts = {})
+    if resource.is_a?(ActiveRecord::Relation)
+      resource = resource.includes(project: :namespace)
+    end
 
-  def header(header, value)
-    @pagination.response.headers[header] = value
+    if paginated?
+      super(@paginator.paginate(resource), opts)
+    else
+      super(resource, opts)
+    end
   end
 end
diff --git a/lib/gitlab/serialize/ci/variables.rb b/lib/gitlab/serializer/ci/variables.rb
index 3a9443bfcd9..c059c454eac 100644
--- a/lib/gitlab/serialize/ci/variables.rb
+++ b/lib/gitlab/serializer/ci/variables.rb
@@ -1,5 +1,5 @@
 module Gitlab
-  module Serialize
+  module Serializer
     module Ci
       # This serializer could make sure our YAML variables' keys and values
       # are always strings. This is more for legacy build data because
diff --git a/lib/gitlab/serializer/pagination.rb b/lib/gitlab/serializer/pagination.rb
new file mode 100644
index 00000000000..bf2c0acc729
--- /dev/null
+++ b/lib/gitlab/serializer/pagination.rb
@@ -0,0 +1,36 @@
+module Gitlab
+  module Serializer
+    class Pagination
+      class InvalidResourceError < StandardError; end
+      include ::API::Helpers::Pagination
+
+      def initialize(request, response)
+        @request = request
+        @response = response
+      end
+
+      def paginate(resource)
+        if resource.respond_to?(:page)
+          super(resource)
+        else
+          raise InvalidResourceError
+        end
+      end
+
+      private
+
+      # Methods needed by `API::Helpers::Pagination`
+      #
+
+      attr_reader :request
+
+      def params
+        @request.query_parameters
+      end
+
+      def header(header, value)
+        @response.headers[header] = value
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/serialize/ci/variables_spec.rb b/spec/lib/gitlab/serializer/ci/variables_spec.rb
index 7ea74da5252..b810c68ea03 100644
--- a/spec/lib/gitlab/serialize/ci/variables_spec.rb
+++ b/spec/lib/gitlab/serializer/ci/variables_spec.rb
@@ -1,6 +1,6 @@
 require 'spec_helper'
 
-describe Gitlab::Serialize::Ci::Variables do
+describe Gitlab::Serializer::Ci::Variables do
   subject do
     described_class.load(described_class.dump(object))
   end
diff --git a/spec/lib/gitlab/serializer/pagination_spec.rb b/spec/lib/gitlab/serializer/pagination_spec.rb
new file mode 100644
index 00000000000..519eb1b274f
--- /dev/null
+++ b/spec/lib/gitlab/serializer/pagination_spec.rb
@@ -0,0 +1,49 @@
+require 'spec_helper'
+
+describe Gitlab::Serializer::Pagination do
+  let(:request) { spy('request') }
+  let(:response) { spy('response') }
+  let(:headers) { spy('headers') }
+
+  before do
+    allow(request).to receive(:query_parameters)
+      .and_return(params)
+
+    allow(response).to receive(:headers)
+      .and_return(headers)
+  end
+
+  let(:pagination) { described_class.new(request, response) }
+
+  describe '#paginate' do
+    subject { pagination.paginate(resource) }
+
+    let(:resource) { User.all }
+    let(:params) { { page: 1, per_page: 2 } }
+
+    context 'when a multiple resources are present in relation' do
+      before { create_list(:user, 3) }
+
+      it 'correctly paginates the resource' do
+        expect(subject.count).to be 2
+      end
+
+      it 'appends relevant headers' do
+        expect(headers).to receive(:[]=).with('X-Total', '3')
+        expect(headers).to receive(:[]=).with('X-Total-Pages', '2')
+        expect(headers).to receive(:[]=).with('X-Per-Page', '2')
+
+        subject
+      end
+    end
+
+    context 'when an invalid resource is about to be paginated' do
+      let(:resource) { create(:user) }
+
+      it 'raises error' do
+        expect { subject }.to raise_error(
+          described_class::InvalidResourceError)
+      end
+    end
+  end
+end
diff --git a/spec/serializers/environment_serializer_spec.rb b/spec/serializers/environment_serializer_spec.rb
index 3c37660885d..1b95f1ff198 100644
--- a/spec/serializers/environment_serializer_spec.rb
+++ b/spec/serializers/environment_serializer_spec.rb
@@ -52,4 +52,136 @@ describe EnvironmentSerializer do
       expect(json).to be_an_instance_of Array
     end
   end
+
+  context 'when representing environments within folders' do
+    let(:serializer) do
+      described_class.new(project: project).within_folders
+    end
+
+    let(:resource) { Environment.all }
+
+    subject { serializer.represent(resource) }
+
+    context 'when there is a single environment' do
+      before { create(:environment, name: 'staging') }
+
+      it 'represents one standalone environment' do
+        expect(subject.count).to eq 1
+        expect(subject.first[:name]).to eq 'staging'
+        expect(subject.first[:size]).to eq 1
+        expect(subject.first[:latest][:name]).to eq 'staging'
+      end
+    end
+
+    context 'when there are multiple environments in folder' do
+      before do
+        create(:environment, name: 'staging/my-review-1')
+        create(:environment, name: 'staging/my-review-2')
+      end
+
+      it 'represents one item that is a folder' do
+        expect(subject.count).to eq 1
+        expect(subject.first[:name]).to eq 'staging'
+        expect(subject.first[:size]).to eq 2
+        expect(subject.first[:latest][:name]).to eq 'staging/my-review-2'
+        expect(subject.first[:latest][:environment_type]).to eq 'staging'
+      end
+    end
+
+    context 'when there are multiple folders and standalone environments' do
+      before do
+        create(:environment, name: 'staging/my-review-1')
+        create(:environment, name: 'staging/my-review-2')
+        create(:environment, name: 'production/my-review-3')
+        create(:environment, name: 'testing')
+      end
+
+      it 'represents multiple items grouped within folders' do
+        expect(subject.count).to eq 3
+
+        expect(subject.first[:name]).to eq 'production'
+        expect(subject.first[:size]).to eq 1
+        expect(subject.first[:latest][:name]).to eq 'production/my-review-3'
+        expect(subject.first[:latest][:environment_type]).to eq 'production'
+        expect(subject.second[:name]).to eq 'staging'
+        expect(subject.second[:size]).to eq 2
+        expect(subject.second[:latest][:name]).to eq 'staging/my-review-2'
+        expect(subject.second[:latest][:environment_type]).to eq 'staging'
+        expect(subject.third[:name]).to eq 'testing'
+        expect(subject.third[:size]).to eq 1
+        expect(subject.third[:latest][:name]).to eq 'testing'
+        expect(subject.third[:latest][:environment_type]).to be_nil
+      end
+    end
+  end
+
+  context 'when used with pagination' do
+    let(:request) { spy('request') }
+    let(:response) { spy('response') }
+    let(:resource) { Environment.all }
+    let(:pagination) { { page: 1, per_page: 2 } }
+
+    let(:serializer) do
+      described_class.new(project: project)
+        .with_pagination(request, response)
+    end
+
+    before do
+      allow(request).to receive(:query_parameters)
+        .and_return(pagination)
+    end
+
+    subject { serializer.represent(resource) }
+
+    it 'creates a paginated serializer' do
+      expect(serializer).to be_paginated
+    end
+
+    context 'when resource is paginatable relation' do
+      context 'when there is a single environment object in relation' do
+        before { create(:environment) }
+
+        it 'serializes environments' do
+          expect(subject.first).to have_key :id
+        end
+      end
+
+      context 'when multiple environment objects are serialized' do
+        before { create_list(:environment, 3) }
+
+        it 'serializes appropriate number of objects' do
+          expect(subject.count).to be 2
+        end
+
+        it 'appends relevant headers' do
+          expect(response).to receive(:[]=).with('X-Total', '3')
+          expect(response).to receive(:[]=).with('X-Total-Pages', '2')
+          expect(response).to receive(:[]=).with('X-Per-Page', '2')
+
+          subject
+        end
+      end
+
+      context 'when grouping environments within folders' do
+        let(:serializer) do
+          described_class.new(project: project)
+            .with_pagination(request, response)
+            .within_folders
+        end
+
+        before do
+          create(:environment, name: 'staging/review-1')
+          create(:environment, name: 'staging/review-2')
+          create(:environment, name: 'production/deploy-3')
+          create(:environment, name: 'testing')
+        end
+
+        it 'paginates grouped items including ordering' do
+          expect(subject.count).to eq 2
+          expect(subject.first[:name]).to eq 'production'
+          expect(subject.second[:name]).to eq 'staging'
+        end
+      end
+    end
+  end
 end
diff --git a/spec/serializers/pipeline_serializer_spec.rb b/spec/serializers/pipeline_serializer_spec.rb
index 7cbf131e41e..2aaef03cb93 100644
--- a/spec/serializers/pipeline_serializer_spec.rb
+++ b/spec/serializers/pipeline_serializer_spec.rb
@@ -52,14 +52,14 @@ describe PipelineSerializer do
         expect(serializer).to be_paginated
       end
 
-      context 'when resource does is not paginatable' do
+      context 'when resource is not paginatable' do
         context 'when a single pipeline object is being serialized' do
           let(:resource) { create(:ci_empty_pipeline) }
           let(:pagination) { { page: 1, per_page: 1 } }
 
           it 'raises error' do
-            expect { subject }
-              .to raise_error(PipelineSerializer::InvalidResourceError)
+            expect { subject }.to raise_error(
+              Gitlab::Serializer::Pagination::InvalidResourceError)
           end
         end
       end