diff --git a/.rubocop.yml b/.rubocop.yml
index 65e27c6..50263f3 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,6 +1,6 @@
 require:
   - rubocop-performance
-  # - rubocop-rspec
+  - rubocop-rspec
 
 Style/FrozenStringLiteralComment:
   Enabled: false
@@ -11,42 +11,68 @@ Style/SymbolArray:
 Style/WordArray:
   Enabled: false
 
-# RSpec/DescribedClass:
-#   Enabled: false
+Style/SymbolProc:
+  Exclude:
+    - 'spec/fixtures/*.rb'
+
+Lint/DuplicateMethods:
+  Exclude:
+    - 'spec/fixtures/*.rb'
+
+RSpec/FilePath:
+  Enabled: false
+
+RSpec/DescribedClass:
+  Enabled: false
+
+RSpec/ExampleLength:
+  Enabled: false
+
+RSpec/MultipleExpectations:
+  Enabled: false
+
+RSpec/NestedGroups:
+  Enabled: false
+
+Performance/TimesMap:
+  Exclude:
+    - 'spec/**/**.rb'
 
 # TODO: Fix these...
 Style/Documentation:
   Enabled: false
 
 Style/GuardClause:
-  Enabled: false
+  Exclude:
+    - 'lib/**/**.rb'
 
 Style/ConditionalAssignment:
-  Enabled: false
+  Exclude:
+    - 'lib/**/**.rb'
 
-Style/ClassAndModuleChildren:
-  Enabled: false
+Style/IfUnlessModifier:
+  Exclude:
+    - 'lib/**/**.rb'
 
 Lint/AssignmentInCondition:
-  Enabled: false
+  Exclude:
+    - 'lib/**/**.rb'
 
-Metrics/ModuleLength:
+Metrics:
+  Exclude:
+    - 'lib/**/**.rb'
+
+Metrics/BlockLength:
   Enabled: false
 
 Layout/LineLength:
-  Enabled: false
-
-Metrics:
-  Enabled: false
+  Exclude:
+    - 'lib/**/**.rb'
 
 Naming/PredicateName:
-  Enabled: false
+  Exclude:
+    - 'lib/**/**.rb'
 
 Naming/AccessorMethodName:
-  Enabled: false
-
-Performance/TimesMap:
-  Enabled: false
-
-# RSpec/BeforeAfterAll:
-#   Enabled: false
+  Exclude:
+    - 'lib/**/**.rb'
diff --git a/Gemfile b/Gemfile
index bcf9e56..01d5a23 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,3 +2,6 @@ source 'https://rubygems.org'
 
 # Specify your gem's dependencies in fast_jsonapi.gemspec
 gemspec
+
+# TODO: Remove once the gem is released...
+gem 'jsonapi-rspec', github: 'jsonapi-rb/jsonapi-rspec'
diff --git a/Rakefile b/Rakefile
index 7881315..88a6ad4 100644
--- a/Rakefile
+++ b/Rakefile
@@ -11,5 +11,5 @@ RuboCop::RakeTask.new('rubocop') do |task|
   ]
 end
 
-RSpec::Core::RakeTask.new(spec: ['rubocop'])
-task(default: :spec)
+RSpec::Core::RakeTask.new(:spec)
+task(default: [:rubocop, :spec])
diff --git a/lib/fast_jsonapi/object_serializer.rb b/lib/fast_jsonapi/object_serializer.rb
index 18bbd72..3de6f6d 100644
--- a/lib/fast_jsonapi/object_serializer.rb
+++ b/lib/fast_jsonapi/object_serializer.rb
@@ -150,6 +150,7 @@ module FastJsonapi
         # ensure that the record type is correctly transformed
         if record_type
           set_type(record_type)
+        # TODO: Remove dead code
         elsif reflected_record_type
           set_type(reflected_record_type)
         end
@@ -231,6 +232,8 @@ module FastJsonapi
         self.cachable_relationships_to_serialize = {} if cachable_relationships_to_serialize.nil?
         self.uncachable_relationships_to_serialize = {} if uncachable_relationships_to_serialize.nil?
 
+        # TODO: Remove this undocumented option.
+        #   Delegate the caching to the serializer exclusively.
         if !relationship.cached
           uncachable_relationships_to_serialize[relationship.name] = relationship
         else
diff --git a/lib/fast_jsonapi/relationship.rb b/lib/fast_jsonapi/relationship.rb
index af9fe23..f80462b 100644
--- a/lib/fast_jsonapi/relationship.rb
+++ b/lib/fast_jsonapi/relationship.rb
@@ -63,6 +63,7 @@ module FastJsonapi
     end
 
     def serializer_for(record, serialization_params)
+      # TODO: Remove this, dead code...
       if @static_serializer
         @static_serializer
 
@@ -78,6 +79,7 @@ module FastJsonapi
         serializer_for_name(record.class.name)
 
       else
+        # TODO: Remove this, dead code...
         raise "Unknown serializer for object #{record.inspect}"
       end
     end
diff --git a/spec/fixtures/_user.rb b/spec/fixtures/_user.rb
new file mode 100644
index 0000000..c993d50
--- /dev/null
+++ b/spec/fixtures/_user.rb
@@ -0,0 +1,28 @@
+class User
+  attr_accessor :uid, :first_name, :last_name, :email
+
+  def self.fake(id = nil)
+    faked = new
+    faked.uid = id || SecureRandom.uuid
+    faked.first_name = FFaker::Name.first_name
+    faked.last_name = FFaker::Name.last_name
+    faked.email = FFaker::Internet.email
+    faked
+  end
+end
+
+class NoSerializerUser < User
+end
+
+class UserSerializer
+  include FastJsonapi::ObjectSerializer
+
+  set_id :uid
+  attributes :first_name, :last_name, :email
+
+  meta do |obj|
+    {
+      email_length: obj.email.size
+    }
+  end
+end
diff --git a/spec/fixtures/actor.rb b/spec/fixtures/actor.rb
new file mode 100644
index 0000000..ba81363
--- /dev/null
+++ b/spec/fixtures/actor.rb
@@ -0,0 +1,72 @@
+require 'active_support/cache'
+
+class Actor < User
+  attr_accessor :movies, :movie_ids
+
+  def self.fake(id = nil)
+    faked = super(id)
+    faked.movies = []
+    faked.movie_ids = []
+    faked
+  end
+
+  def movie_urls
+    {
+      movie_url: movies[0]&.url
+    }
+  end
+end
+
+class ActorSerializer < UserSerializer
+  set_type :actor
+
+  attribute :email, if: ->(_object, params) { params[:conditionals_off].nil? }
+
+  has_many(
+    :played_movies,
+    serializer: :movie,
+    links: :movie_urls,
+    if: ->(_object, params) { params[:conditionals_off].nil? }
+  ) do |object|
+    object.movies
+  end
+end
+
+class CamelCaseActorSerializer
+  include FastJsonapi::ObjectSerializer
+
+  set_key_transform :camel
+
+  set_id :uid
+  set_type :user_actor
+  attributes :first_name
+
+  link :movie_url do |obj|
+    obj.movie_urls.values[0]
+  end
+
+  has_many(
+    :played_movies,
+    serializer: :movie
+  ) do |object|
+    object.movies
+  end
+end
+
+class BadMovieSerializerActorSerializer < ActorSerializer
+  has_many :played_movies, serializer: :bad, object_method_name: :movies
+end
+
+module Cached
+  class ActorSerializer < ::ActorSerializer
+    # TODO: Fix this, the serializer gets cached on inherited classes...
+    has_many :played_movies, serializer: :movie do |object|
+      object.movies
+    end
+
+    cache_options(
+      store: ActiveSupport::Cache::MemoryStore.new,
+      namespace: 'test'
+    )
+  end
+end
diff --git a/spec/fixtures/movie.rb b/spec/fixtures/movie.rb
new file mode 100644
index 0000000..2ba1666
--- /dev/null
+++ b/spec/fixtures/movie.rb
@@ -0,0 +1,116 @@
+class Movie
+  attr_accessor(
+    :id,
+    :name,
+    :year,
+    :actors,
+    :actor_ids,
+    :polymorphics,
+    :owner,
+    :owner_id
+  )
+
+  def self.fake(id = nil)
+    faked = new
+    faked.id = id || SecureRandom.uuid
+    faked.name = FFaker::Movie.title
+    faked.year = FFaker::Vehicle.year
+    faked.actors = []
+    faked.actor_ids = []
+    faked.polymorphics = []
+    faked
+  end
+
+  def url(obj = nil)
+    @url ||= FFaker::Internet.http_url
+    return @url if obj.nil?
+
+    @url + '?' + obj.hash.to_s
+  end
+
+  def owner=(ownr)
+    @owner = ownr
+    @owner_id = ownr.uid
+  end
+
+  def actors=(acts)
+    @actors = acts
+    @actor_ids = actors.map do |actor|
+      actor.movies << self
+      actor.uid
+    end
+  end
+end
+
+class MovieSerializer
+  include FastJsonapi::ObjectSerializer
+
+  set_type :movie
+
+  attributes :name
+  attribute :release_year do |object|
+    object.year
+  end
+
+  link :self, :url
+
+  belongs_to :owner, serializer: UserSerializer
+  has_many(
+    :actors,
+    links: {
+      actors_self: :url,
+      related: ->(obj) { obj.url(obj) }
+    }
+  )
+  has_one(
+    :creator,
+    object_method_name: :owner,
+    id_method_name: :uid,
+    serializer: ->(object, _params) { UserSerializer if object.is_a?(User) }
+  )
+  has_many(
+    :actors_and_users,
+    id_method_name: :uid,
+    polymorphic: {
+      Actor => :actor,
+      User => :user
+    }
+  ) do |obj|
+    obj.polymorphics
+  end
+
+  has_many(
+    :dynamic_actors_and_users,
+    id_method_name: :uid,
+    polymorphic: true
+  ) do |obj|
+    obj.polymorphics
+  end
+
+  has_many(
+    :auto_detected_actors_and_users,
+    id_method_name: :uid
+  ) do |obj|
+    obj.polymorphics
+  end
+end
+
+module Cached
+  class MovieSerializer < ::MovieSerializer
+    cache_options(
+      store: ActorSerializer.cache_store_instance,
+      namespace: 'test'
+    )
+
+    has_one(
+      :creator,
+      id_method_name: :uid,
+      serializer: :actor,
+      # TODO: Remove this undocumented option.
+      #   Delegate the caching to the serializer exclusively.
+      cached: false
+    ) do |obj|
+      obj.owner
+    end
+  end
+end
diff --git a/spec/integration/attributes_fields_spec.rb b/spec/integration/attributes_fields_spec.rb
new file mode 100644
index 0000000..2bcdd5e
--- /dev/null
+++ b/spec/integration/attributes_fields_spec.rb
@@ -0,0 +1,63 @@
+require 'spec_helper'
+
+RSpec.describe FastJsonapi::ObjectSerializer do
+  let(:actor) do
+    act = Actor.fake
+    act.movies = [Movie.fake]
+    act
+  end
+  let(:params) { {} }
+  let(:serialized) do
+    ActorSerializer.new(actor, params).serializable_hash.as_json
+  end
+
+  describe 'attributes' do
+    it do
+      expect(serialized['data']).to have_id(actor.uid)
+      expect(serialized['data']).to have_type('actor')
+
+      expect(serialized['data'])
+        .to have_jsonapi_attributes('first_name', 'last_name', 'email').exactly
+      expect(serialized['data']).to have_attribute('first_name')
+        .with_value(actor.first_name)
+      expect(serialized['data']).to have_attribute('last_name')
+        .with_value(actor.last_name)
+      expect(serialized['data']).to have_attribute('email')
+        .with_value(actor.email)
+    end
+
+    context 'with nil identifier' do
+      before { actor.uid = nil }
+
+      it { expect(serialized['data']).to have_id(nil) }
+    end
+
+    context 'with `if` conditions' do
+      let(:params) { { params: { conditionals_off: 'yes' } } }
+
+      it do
+        expect(serialized['data']).not_to have_attribute('email')
+      end
+    end
+
+    context 'with include and fields' do
+      let(:params) do
+        {
+          include: [:played_movies],
+          fields: { movie: [:release_year], actor: [:first_name] }
+        }
+      end
+
+      it do
+        expect(serialized['data'])
+          .to have_jsonapi_attributes(:first_name).exactly
+
+        expect(serialized['included']).to include(
+          have_type('movie')
+          .and(have_id(actor.movies[0].id))
+          .and(have_jsonapi_attributes('release_year').exactly)
+        )
+      end
+    end
+  end
+end
diff --git a/spec/integration/caching_spec.rb b/spec/integration/caching_spec.rb
new file mode 100644
index 0000000..eda3872
--- /dev/null
+++ b/spec/integration/caching_spec.rb
@@ -0,0 +1,29 @@
+require 'spec_helper'
+
+RSpec.describe FastJsonapi::ObjectSerializer do
+  let(:actor) do
+    faked = Actor.fake
+    movie = Movie.fake
+    movie.owner = User.fake
+    movie.actors = [faked]
+    faked.movies = [movie]
+    faked
+  end
+  let(:cache_store) { Cached::ActorSerializer.cache_store_instance }
+
+  describe 'with caching' do
+    it do
+      expect(cache_store.delete(actor, namespace: 'test')).to be(false)
+
+      Cached::ActorSerializer.new(
+        [actor, actor], include: ['played_movies', 'played_movies.owner']
+      ).serializable_hash
+
+      expect(cache_store.delete(actor, namespace: 'test')).to be(true)
+      expect(cache_store.delete(actor.movies[0], namespace: 'test')).to be(true)
+      expect(
+        cache_store.delete(actor.movies[0].owner, namespace: 'test')
+      ).to be(false)
+    end
+  end
+end
diff --git a/spec/integration/errors_spec.rb b/spec/integration/errors_spec.rb
new file mode 100644
index 0000000..2d94fde
--- /dev/null
+++ b/spec/integration/errors_spec.rb
@@ -0,0 +1,25 @@
+require 'spec_helper'
+
+RSpec.describe FastJsonapi::ObjectSerializer do
+  let(:actor) { Actor.fake }
+  let(:params) { {} }
+
+  describe 'with errors' do
+    it do
+      expect do
+        BadMovieSerializerActorSerializer.new(
+          actor, include: ['played_movies']
+        )
+      end.to raise_error(
+        NameError, /cannot resolve a serializer class for 'bad'/
+      )
+    end
+
+    it do
+      expect { ActorSerializer.new(actor, include: ['bad_include']) }
+        .to raise_error(
+          ArgumentError, /bad_include is not specified as a relationship/
+        )
+    end
+  end
+end
diff --git a/spec/integration/key_transform_spec.rb b/spec/integration/key_transform_spec.rb
new file mode 100644
index 0000000..5959c5f
--- /dev/null
+++ b/spec/integration/key_transform_spec.rb
@@ -0,0 +1,19 @@
+require 'spec_helper'
+
+RSpec.describe FastJsonapi::ObjectSerializer do
+  let(:actor) { Actor.fake }
+  let(:params) { {} }
+  let(:serialized) do
+    CamelCaseActorSerializer.new(actor, params).serializable_hash.as_json
+  end
+
+  describe 'camel case key tranformation' do
+    it do
+      expect(serialized['data']).to have_id(actor.uid)
+      expect(serialized['data']).to have_type('UserActor')
+      expect(serialized['data']).to have_attribute('FirstName')
+      expect(serialized['data']).to have_relationship('PlayedMovies')
+      expect(serialized['data']).to have_link('MovieUrl').with_value(nil)
+    end
+  end
+end
diff --git a/spec/integration/links_spec.rb b/spec/integration/links_spec.rb
new file mode 100644
index 0000000..0fb9d57
--- /dev/null
+++ b/spec/integration/links_spec.rb
@@ -0,0 +1,47 @@
+require 'spec_helper'
+
+RSpec.describe FastJsonapi::ObjectSerializer do
+  let(:movie) do
+    faked = Movie.fake
+    faked.actors = [Actor.fake]
+    faked
+  end
+  let(:params) { {} }
+  let(:serialized) do
+    MovieSerializer.new(movie, params).serializable_hash.as_json
+  end
+
+  describe 'links' do
+    it do
+      expect(serialized['data']).to have_link('self').with_value(movie.url)
+      expect(serialized['data']['relationships']['actors'])
+        .to have_link('actors_self').with_value(movie.url)
+      expect(serialized['data']['relationships']['actors'])
+        .to have_link('related').with_value(movie.url(movie))
+    end
+
+    context 'with included records' do
+      let(:serialized) do
+        ActorSerializer.new(movie.actors[0]).serializable_hash.as_json
+      end
+
+      it do
+        expect(serialized['data']['relationships']['played_movies'])
+          .to have_link('movie_url').with_value(movie.url)
+      end
+    end
+
+    context 'with root link' do
+      let(:params) do
+        {
+          links: { 'root_link' => FFaker::Internet.http_url }
+        }
+      end
+
+      it do
+        expect(serialized)
+          .to have_link('root_link').with_value(params[:links]['root_link'])
+      end
+    end
+  end
+end
diff --git a/spec/integration/meta_spec.rb b/spec/integration/meta_spec.rb
new file mode 100644
index 0000000..7e65b5a
--- /dev/null
+++ b/spec/integration/meta_spec.rb
@@ -0,0 +1,25 @@
+require 'spec_helper'
+
+RSpec.describe FastJsonapi::ObjectSerializer do
+  let(:user) { User.fake }
+  let(:params) { {} }
+  let(:serialized) do
+    UserSerializer.new(user, params).serializable_hash.as_json
+  end
+
+  it do
+    expect(serialized['data']).to have_meta('email_length' => user.email.size)
+  end
+
+  context 'with root meta' do
+    let(:params) do
+      {
+        meta: { 'code' => FFaker::Internet.password }
+      }
+    end
+
+    it do
+      expect(serialized).to have_meta(params[:meta])
+    end
+  end
+end
diff --git a/spec/integration/relationships_spec.rb b/spec/integration/relationships_spec.rb
new file mode 100644
index 0000000..e48ccb0
--- /dev/null
+++ b/spec/integration/relationships_spec.rb
@@ -0,0 +1,126 @@
+require 'spec_helper'
+
+RSpec.describe FastJsonapi::ObjectSerializer do
+  let(:movie) do
+    mov = Movie.fake
+    mov.actors = rand(2..5).times.map { Actor.fake }
+    mov.owner = User.fake
+    poly_act = Actor.fake
+    poly_act.movies = [Movie.fake]
+    mov.polymorphics = [User.fake, poly_act]
+    mov
+  end
+  let(:params) { {} }
+  let(:serialized) do
+    MovieSerializer.new(movie, params).serializable_hash.as_json
+  end
+
+  describe 'relationships' do
+    it do
+      actors_rel = movie.actors.map { |a| { 'id' => a.uid, 'type' => 'actor' } }
+
+      expect(serialized['data'])
+        .to have_relationship('actors').with_data(actors_rel)
+
+      expect(serialized['data'])
+        .to have_relationship('owner')
+        .with_data('id' => movie.owner.uid, 'type' => 'user')
+
+      expect(serialized['data'])
+        .to have_relationship('creator')
+        .with_data('id' => movie.owner.uid, 'type' => 'user')
+
+      expect(serialized['data'])
+        .to have_relationship('actors_and_users')
+        .with_data(
+          [
+            { 'id' => movie.polymorphics[0].uid, 'type' => 'user' },
+            { 'id' => movie.polymorphics[1].uid, 'type' => 'actor' }
+          ]
+        )
+
+      expect(serialized['data'])
+        .to have_relationship('dynamic_actors_and_users')
+        .with_data(
+          [
+            { 'id' => movie.polymorphics[0].uid, 'type' => 'user' },
+            { 'id' => movie.polymorphics[1].uid, 'type' => 'actor' }
+          ]
+        )
+
+      expect(serialized['data'])
+        .to have_relationship('auto_detected_actors_and_users')
+        .with_data(
+          [
+            { 'id' => movie.polymorphics[0].uid, 'type' => 'user' },
+            { 'id' => movie.polymorphics[1].uid, 'type' => 'actor' }
+          ]
+        )
+    end
+
+    context 'with include' do
+      let(:params) do
+        { include: [:actors] }
+      end
+
+      it do
+        movie.actors.each do |actor|
+          expect(serialized['included']).to include(
+            have_type('actor')
+            .and(have_id(actor.uid))
+            .and(have_relationship('played_movies')
+            .with_data([{ 'id' => actor.movies[0].id, 'type' => 'movie' }]))
+          )
+        end
+      end
+
+      context 'with `if` conditions' do
+        let(:params) do
+          {
+            include: ['actors'],
+            params: { conditionals_off: 'yes' }
+          }
+        end
+
+        it do
+          movie.actors.each do |actor|
+            expect(serialized['included']).not_to include(
+              have_type('actor')
+              .and(have_id(actor.uid))
+              .and(have_relationship('played_movies'))
+            )
+          end
+        end
+      end
+
+      context 'with polymorphic' do
+        let(:params) do
+          { include: ['actors_and_users.played_movies'] }
+        end
+
+        it do
+          expect(serialized['included']).to include(
+            have_type('user').and(have_id(movie.polymorphics[0].uid))
+          )
+
+          expect(serialized['included']).to include(
+            have_type('movie').and(have_id(movie.polymorphics[1].movies[0].id))
+          )
+
+          expect(serialized['included']).to include(
+            have_type('actor')
+            .and(have_id(movie.polymorphics[1].uid))
+            .and(
+              have_relationship('played_movies').with_data(
+                [{
+                  'id' => movie.polymorphics[1].movies[0].id,
+                  'type' => 'movie'
+                }]
+              )
+            )
+          )
+        end
+      end
+    end
+  end
+end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 496ab23..9622107 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -6,14 +6,19 @@ SimpleCov.start do
 end
 SimpleCov.minimum_coverage 90
 
-require 'active_record'
+require 'active_support/core_ext/object/json'
 require 'fast_jsonapi'
+require 'ffaker'
+require 'rspec'
+require 'jsonapi/rspec'
 require 'byebug'
+require 'securerandom'
 
-Dir[File.dirname(__FILE__) + '/shared/contexts/*.rb'].each {|file| require file }
-Dir[File.dirname(__FILE__) + '/shared/examples/*.rb'].each {|file| require file }
+Dir[File.expand_path('spec/fixtures/*.rb')].sort.each { |f| require f }
 
 RSpec.configure do |config|
+  config.include JSONAPI::RSpec
+
   config.mock_with :rspec
   config.filter_run_when_matching :focus
   config.disable_monkey_patching!