require 'spec_helper'

describe Grape::Entity do

  let(:fresh_class) { Class.new(Grape::Entity) }

  context 'class methods' do
    subject { fresh_class }

    describe '.expose' do
      context 'multiple attributes' do
        it 'is able to add multiple exposed attributes with a single call' do
          subject.expose :name, :email, :location
          expect(subject.exposures.size).to eq 3
        end

        it 'sets the same options for all exposures passed' do
          subject.expose :name, :email, :location, documentation: true
          subject.exposures.values.each { |v| expect(v).to eq(documentation: true) }
        end
      end

      context 'option validation' do
        it 'makes sure that :as only works on single attribute calls' do
          expect { subject.expose :name, :email, as: :foo }.to raise_error ArgumentError
          expect { subject.expose :name, as: :foo }.not_to raise_error
        end

        it 'makes sure that :format_with as a proc cannot be used with a block' do
          expect { subject.expose :name, format_with: proc {} {} }.to raise_error ArgumentError
        end

        it 'makes sure unknown options are not silently ignored' do
          expect { subject.expose :name, unknown: nil }.to raise_error ArgumentError
        end
      end

      context 'with a block' do
        it 'errors out if called with multiple attributes' do
          expect { subject.expose(:name, :email) { true } }.to raise_error ArgumentError
        end

        it 'references an instance of the entity with :using option' do
          module EntitySpec
            class SomeObject1
              attr_accessor :prop1

              def initialize
                @prop1 = 'value1'
              end
            end

            class BogusEntity < Grape::Entity
              expose :prop1
            end
          end

          subject.expose(:bogus, using: EntitySpec::BogusEntity) do |entity|
            entity.prop1 = 'MODIFIED 2'
            entity
          end

          object = EntitySpec::SomeObject1.new
          value = subject.represent(object).send(:value_for, :bogus)
          expect(value).to be_instance_of EntitySpec::BogusEntity

          prop1 = value.send(:value_for, :prop1)
          expect(prop1).to eq 'MODIFIED 2'
        end

        context 'with parameters passed to the block' do
          it 'sets the :proc option in the exposure options' do
            block = lambda { |_| true }
            subject.expose :name, using: 'Awesome', &block
            expect(subject.exposures[:name]).to eq(proc: block, using: 'Awesome')
          end

          it 'references an instance of the entity without any options' do
            subject.expose(:size) { |_| self }
            expect(subject.represent(Hash.new).send(:value_for, :size)).to be_an_instance_of fresh_class
          end
        end

        context 'with no parameters passed to the block' do
          it 'adds a nested exposure' do
            subject.expose :awesome do
              subject.expose :nested do
                subject.expose :moar_nested, as: 'weee'
              end
              subject.expose :another_nested, using: 'Awesome'
            end

            expect(subject.exposures).to eq(
                                              awesome: {},
                                              awesome__nested: { nested: true },
                                              awesome__nested__moar_nested: { as: 'weee', nested: true },
                                              awesome__another_nested: { using: 'Awesome', nested: true }
            )
          end

          it 'represents the exposure as a hash of its nested exposures' do
            subject.expose :awesome do
              subject.expose(:nested) { |_| 'value' }
              subject.expose(:another_nested) { |_| 'value' }
            end

            expect(subject.represent({}).send(:value_for, :awesome)).to eq(
                                                                             nested: 'value',
                                                                             another_nested: 'value'
            )
          end

          it 'does not represent attributes, declared inside nested exposure, outside of it' do
            subject.expose :awesome do
              subject.expose(:nested) { |_| 'value' }
              subject.expose(:another_nested) { |_| 'value' }
              subject.expose :second_level_nested do
                subject.expose(:deeply_exposed_attr) { |_| 'value' }
              end
            end

            expect(subject.represent({}).serializable_hash).to eq(
                                                                    awesome: {
                                                                      nested: 'value',
                                                                      another_nested: 'value',
                                                                      second_level_nested: {
                                                                        deeply_exposed_attr: 'value'
                                                                      }
                                                                    }
            )
          end

          it 'complex nested attributes' do
            class ClassRoom < Grape::Entity
              expose(:parents, using: 'Parent') { |_| [{}, {}] }
            end

            class Person < Grape::Entity
              expose :user do
                expose(:in_first) { |_| 'value' }
              end
            end

            class Student < Person
              expose :user do
                expose(:user_id) { |_| 'value' }
                expose(:user_display_id, as: :display_id) { |_| 'value' }
              end
            end

            class Parent < Person
              expose(:children, using: 'Student') { |_| [{}, {}] }
            end

            expect(ClassRoom.represent({}).serializable_hash).to eq(
                                                                      parents: [
                                                                        {
                                                                          user: { in_first: 'value' },
                                                                          children: [
                                                                            { user: { in_first: 'value', user_id: 'value', display_id: 'value' } },
                                                                            { user: { in_first: 'value', user_id: 'value', display_id: 'value' } }
                                                                          ]
                                                                        },
                                                                        {
                                                                          user: { in_first: 'value' },
                                                                          children: [
                                                                            { user: { in_first: 'value', user_id: 'value', display_id: 'value' } },
                                                                            { user: { in_first: 'value', user_id: 'value', display_id: 'value' } }
                                                                          ]
                                                                        }
                                                                      ]
            )
          end

          it 'is safe if its nested exposures are safe' do
            subject.with_options safe: true do
              subject.expose :awesome do
                subject.expose(:nested) { |_| 'value' }
              end
              subject.expose :not_awesome do
                subject.expose :nested
              end
            end

            valid_keys = subject.represent({}).valid_exposures.keys

            expect(valid_keys.include?(:awesome)).to be true
            expect(valid_keys.include?(:not_awesome)).to be false
          end
        end
      end

      context 'inherited exposures' do
        it 'returns exposures from an ancestor' do
          subject.expose :name, :email
          child_class = Class.new(subject)

          expect(child_class.exposures).to eq(subject.exposures)
        end

        it 'returns exposures from multiple ancestor' do
          subject.expose :name, :email
          parent_class = Class.new(subject)
          child_class  = Class.new(parent_class)

          expect(child_class.exposures).to eq(subject.exposures)
        end

        it 'returns descendant exposures as a priority' do
          subject.expose :name, :email
          child_class = Class.new(subject)
          child_class.expose :name do |_|
            'foo'
          end

          expect(subject.exposures[:name]).not_to have_key :proc
          expect(child_class.exposures[:name]).to have_key :proc
        end
      end

      context 'register formatters' do
        let(:date_formatter) { lambda { |date| date.strftime('%m/%d/%Y') } }

        it 'registers a formatter' do
          subject.format_with :timestamp, &date_formatter

          expect(subject.formatters[:timestamp]).not_to be_nil
        end

        it 'inherits formatters from ancestors' do
          subject.format_with :timestamp, &date_formatter
          child_class = Class.new(subject)

          expect(child_class.formatters).to eq subject.formatters
        end

        it 'does not allow registering a formatter without a block' do
          expect { subject.format_with :foo }.to raise_error ArgumentError
        end

        it 'formats an exposure with a registered formatter' do
          subject.format_with :timestamp do |date|
            date.strftime('%m/%d/%Y')
          end

          subject.expose :birthday, format_with: :timestamp

          model  = { birthday: Time.gm(2012, 2, 27) }
          expect(subject.new(double(model)).as_json[:birthday]).to eq '02/27/2012'
        end

        it 'formats an exposure with a :format_with lambda that returns a value from the entity instance' do
          object = Hash.new

          subject.expose(:size, format_with: lambda { |_value| self.object.class.to_s })
          expect(subject.represent(object).send(:value_for, :size)).to eq object.class.to_s
        end

        it 'formats an exposure with a :format_with symbol that returns a value from the entity instance' do
          subject.format_with :size_formatter do |_date|
            self.object.class.to_s
          end

          object = Hash.new

          subject.expose(:size, format_with: :size_formatter)
          expect(subject.represent(object).send(:value_for, :size)).to eq object.class.to_s
        end
      end
    end

    describe '.with_options' do
      it 'raises an error for unknown options' do
        block = proc do
          with_options(unknown: true) do
            expose :awesome_thing
          end
        end

        expect { subject.class_eval(&block) }.to raise_error ArgumentError
      end

      it 'applies the options to all exposures inside' do
        subject.class_eval do
          with_options(if: { awesome: true }) do
            expose :awesome_thing, using: 'Awesome'
          end
        end

        expect(subject.exposures[:awesome_thing]).to eq(if: { awesome: true }, using: 'Awesome')
      end

      it 'allows for nested .with_options' do
        subject.class_eval do
          with_options(if: { awesome: true }) do
            with_options(using: 'Something') do
              expose :awesome_thing
            end
          end
        end

        expect(subject.exposures[:awesome_thing]).to eq(if: { awesome: true }, using: 'Something')
      end

      it 'overrides nested :as option' do
        subject.class_eval do
          with_options(as: :sweet) do
            expose :awesome_thing, as: :extra_smooth
          end
        end

        expect(subject.exposures[:awesome_thing]).to eq(as: :extra_smooth)
      end

      it 'merges nested :if option' do
        match_proc = lambda { |_obj, _opts| true }

        subject.class_eval do
          # Symbol
          with_options(if: :awesome) do
            # Hash
            with_options(if: { awesome: true }) do
              # Proc
              with_options(if: match_proc) do
                # Hash (override existing key and merge new key)
                with_options(if: { awesome: false, less_awesome: true }) do
                  expose :awesome_thing
                end
              end
            end
          end
        end

        expect(subject.exposures[:awesome_thing]).to eq(
                                                          if: { awesome: false, less_awesome: true },
                                                          if_extras: [:awesome, match_proc]
        )
      end

      it 'merges nested :unless option' do
        match_proc = lambda { |_, _| true }

        subject.class_eval do
          # Symbol
          with_options(unless: :awesome) do
            # Hash
            with_options(unless: { awesome: true }) do
              # Proc
              with_options(unless: match_proc) do
                # Hash (override existing key and merge new key)
                with_options(unless: { awesome: false, less_awesome: true }) do
                  expose :awesome_thing
                end
              end
            end
          end
        end

        expect(subject.exposures[:awesome_thing]).to eq(
                                                          unless: { awesome: false, less_awesome: true },
                                                          unless_extras: [:awesome, match_proc]
        )
      end

      it 'overrides nested :using option' do
        subject.class_eval do
          with_options(using: 'Something') do
            expose :awesome_thing, using: 'SomethingElse'
          end
        end

        expect(subject.exposures[:awesome_thing]).to eq(using: 'SomethingElse')
      end

      it 'aliases :with option to :using option' do
        subject.class_eval do
          with_options(using: 'Something') do
            expose :awesome_thing, with: 'SomethingElse'
          end
        end
        expect(subject.exposures[:awesome_thing]).to eq(using: 'SomethingElse')
      end

      it 'overrides nested :proc option' do
        match_proc = lambda { |_obj, _opts| 'more awesomer' }

        subject.class_eval do
          with_options(proc: lambda { |_obj, _opts| 'awesome' }) do
            expose :awesome_thing, proc: match_proc
          end
        end

        expect(subject.exposures[:awesome_thing]).to eq(proc: match_proc)
      end

      it 'overrides nested :documentation option' do
        subject.class_eval do
          with_options(documentation: { desc: 'Description.' }) do
            expose :awesome_thing, documentation: { desc: 'Other description.' }
          end
        end

        expect(subject.exposures[:awesome_thing]).to eq(documentation: { desc: 'Other description.' })
      end
    end

    describe '.represent' do
      it 'returns a single entity if called with one object' do
        expect(subject.represent(Object.new)).to be_kind_of(subject)
      end

      it 'returns a single entity if called with a hash' do
        expect(subject.represent(Hash.new)).to be_kind_of(subject)
      end

      it 'returns multiple entities if called with a collection' do
        representation = subject.represent(4.times.map { Object.new })
        expect(representation).to be_kind_of Array
        expect(representation.size).to eq(4)
        expect(representation.reject { |r| r.kind_of?(subject) }).to be_empty
      end

      it 'adds the collection: true option if called with a collection' do
        representation = subject.represent(4.times.map { Object.new })
        representation.each { |r| expect(r.options[:collection]).to be true }
      end

      it 'returns a serialized hash of a single object if serializable: true' do
        subject.expose(:awesome) { |_| true }
        representation = subject.represent(Object.new, serializable: true)
        expect(representation).to eq(awesome: true)
      end

      it 'returns a serialized array of hashes of multiple objects if serializable: true' do
        subject.expose(:awesome) { |_| true }
        representation = subject.represent(2.times.map { Object.new }, serializable: true)
        expect(representation).to eq([{ awesome: true }, { awesome: true }])
      end

      it 'returns a serialized hash of a hash' do
        subject.expose(:awesome)
        representation = subject.represent({ awesome: true }, serializable: true)
        expect(representation).to eq(awesome: true)
      end
    end

    describe '.present_collection' do
      it 'make the objects accessible' do
        subject.present_collection true
        subject.expose :items

        representation = subject.represent(4.times.map { Object.new })
        expect(representation).to be_kind_of(subject)
        expect(representation.object).to be_kind_of(Hash)
        expect(representation.object).to have_key :items
        expect(representation.object[:items]).to be_kind_of Array
        expect(representation.object[:items].size).to be 4
      end

      it 'serializes items with my root name' do
        subject.present_collection true, :my_items
        subject.expose :my_items

        representation = subject.represent(4.times.map { Object.new }, serializable: true)
        expect(representation).to be_kind_of(Hash)
        expect(representation).to have_key :my_items
        expect(representation[:my_items]).to be_kind_of Array
        expect(representation[:my_items].size).to be 4
      end
    end

    describe '.root' do
      context 'with singular and plural root keys' do
        before(:each) do
          subject.root 'things', 'thing'
        end

        context 'with a single object' do
          it 'allows a root element name to be specified' do
            representation = subject.represent(Object.new)
            expect(representation).to be_kind_of Hash
            expect(representation).to have_key 'thing'
            expect(representation['thing']).to be_kind_of(subject)
          end
        end

        context 'with an array of objects' do
          it 'allows a root element name to be specified' do
            representation = subject.represent(4.times.map { Object.new })
            expect(representation).to be_kind_of Hash
            expect(representation).to have_key 'things'
            expect(representation['things']).to be_kind_of Array
            expect(representation['things'].size).to eq 4
            expect(representation['things'].reject { |r| r.kind_of?(subject) }).to be_empty
          end
        end

        context 'it can be overridden' do
          it 'can be disabled' do
            representation = subject.represent(4.times.map { Object.new }, root: false)
            expect(representation).to be_kind_of Array
            expect(representation.size).to eq 4
            expect(representation.reject { |r| r.kind_of?(subject) }).to be_empty
          end
          it 'can use a different name' do
            representation = subject.represent(4.times.map { Object.new }, root: 'others')
            expect(representation).to be_kind_of Hash
            expect(representation).to have_key 'others'
            expect(representation['others']).to be_kind_of Array
            expect(representation['others'].size).to eq 4
            expect(representation['others'].reject { |r| r.kind_of?(subject) }).to be_empty
          end
        end
      end

      context 'with singular root key' do
        before(:each) do
          subject.root nil, 'thing'
        end

        context 'with a single object' do
          it 'allows a root element name to be specified' do
            representation = subject.represent(Object.new)
            expect(representation).to be_kind_of Hash
            expect(representation).to have_key 'thing'
            expect(representation['thing']).to be_kind_of(subject)
          end
        end

        context 'with an array of objects' do
          it 'allows a root element name to be specified' do
            representation = subject.represent(4.times.map { Object.new })
            expect(representation).to be_kind_of Array
            expect(representation.size).to eq 4
            expect(representation.reject { |r| r.kind_of?(subject) }).to be_empty
          end
        end
      end

      context 'with plural root key' do
        before(:each) do
          subject.root 'things'
        end

        context 'with a single object' do
          it 'allows a root element name to be specified' do
            expect(subject.represent(Object.new)).to be_kind_of(subject)
          end
        end

        context 'with an array of objects' do
          it 'allows a root element name to be specified' do
            representation = subject.represent(4.times.map { Object.new })
            expect(representation).to be_kind_of Hash
            expect(representation).to have_key('things')
            expect(representation['things']).to be_kind_of Array
            expect(representation['things'].size).to eq 4
            expect(representation['things'].reject { |r| r.kind_of?(subject) }).to be_empty
          end
        end
      end
    end

    describe '#initialize' do
      it 'takes an object and an optional options hash' do
        expect { subject.new(Object.new) }.not_to raise_error
        expect { subject.new }.to raise_error ArgumentError
        expect { subject.new(Object.new, {}) }.not_to raise_error
      end

      it 'has attribute readers for the object and options' do
        entity = subject.new('abc', {})
        expect(entity.object).to eq 'abc'
        expect(entity.options).to eq({})
      end
    end

  end

  context 'instance methods' do

    let(:model) { double(attributes) }

    let(:attributes) {
      {
        name: 'Bob Bobson',
        email: 'bob@example.com',
        birthday: Time.gm(2012, 2, 27),
        fantasies: ['Unicorns', 'Double Rainbows', 'Nessy'],
        friends: [
          double(name: 'Friend 1', email: 'friend1@example.com', fantasies: [], birthday: Time.gm(2012, 2, 27), friends: []),
          double(name: 'Friend 2', email: 'friend2@example.com', fantasies: [], birthday: Time.gm(2012, 2, 27), friends: [])
        ]
      }
    }

    subject { fresh_class.new(model) }

    describe '#serializable_hash' do
      it 'does not throw an exception if a nil options object is passed' do
        expect { fresh_class.new(model).serializable_hash(nil) }.not_to raise_error
      end

      it 'does not blow up when the model is nil' do
        fresh_class.expose :name
        expect { fresh_class.new(nil).serializable_hash }.not_to raise_error
      end

      context 'with safe option' do
        it 'does not throw an exception when an attribute is not found on the object' do
          fresh_class.expose :name, :nonexistent_attribute, safe: true
          expect { fresh_class.new(model).serializable_hash }.not_to raise_error
        end

        it "does not expose attributes that don't exist on the object" do
          fresh_class.expose :email, :nonexistent_attribute, :name, safe: true

          res = fresh_class.new(model).serializable_hash
          expect(res).to have_key :email
          expect(res).not_to have_key :nonexistent_attribute
          expect(res).to have_key :name
        end

        it "does not expose attributes that don't exist on the object, even with criteria" do
          fresh_class.expose :email
          fresh_class.expose :nonexistent_attribute, safe: true, if: lambda { false }
          fresh_class.expose :nonexistent_attribute2, safe: true, if: lambda { true }

          res = fresh_class.new(model).serializable_hash
          expect(res).to have_key :email
          expect(res).not_to have_key :nonexistent_attribute
          expect(res).not_to have_key :nonexistent_attribute2
        end
      end

      context 'without safe option' do
        it 'throws an exception when an attribute is not found on the object' do
          fresh_class.expose :name, :nonexistent_attribute
          expect { fresh_class.new(model).serializable_hash }.to raise_error
        end

        it "exposes attributes that don't exist on the object only when they are generated by a block" do
          fresh_class.expose :nonexistent_attribute do |_model, _opts|
            'well, I do exist after all'
          end
          res = fresh_class.new(model).serializable_hash
          expect(res).to have_key :nonexistent_attribute
        end

        it 'does not expose attributes that are generated by a block but have not passed criteria' do
          fresh_class.expose :nonexistent_attribute, proc: lambda { |_model, _opts|
            'I exist, but it is not yet my time to shine'
          },                                         if: lambda { |_model, _opts| false }
          res = fresh_class.new(model).serializable_hash
          expect(res).not_to have_key :nonexistent_attribute
        end
      end

      it "exposes attributes that don't exist on the object only when they are generated by a block with options" do
        module EntitySpec
          class TestEntity < Grape::Entity
          end
        end

        fresh_class.expose :nonexistent_attribute, using: EntitySpec::TestEntity do |_model, _opts|
          'well, I do exist after all'
        end
        res = fresh_class.new(model).serializable_hash
        expect(res).to have_key :nonexistent_attribute
      end

      it 'does not expose attributes that are generated by a block but have not passed criteria' do
        fresh_class.expose :nonexistent_attribute, proc: lambda { |_, _|
          'I exist, but it is not yet my time to shine'
        },                                         if: lambda { |_, _| false }
        res = fresh_class.new(model).serializable_hash
        expect(res).not_to have_key :nonexistent_attribute
      end

      context '#serializable_hash' do
        module EntitySpec
          class EmbeddedExample
            def serializable_hash(_opts = {})
              { abc: 'def' }
            end
          end

          class EmbeddedExampleWithHash
            def name
              'abc'
            end

            def embedded
              { a: nil, b: EmbeddedExample.new }
            end
          end

          class EmbeddedExampleWithMany
            def name
              'abc'
            end

            def embedded
              [EmbeddedExample.new, EmbeddedExample.new]
            end
          end

          class EmbeddedExampleWithOne
            def name
              'abc'
            end

            def embedded
              EmbeddedExample.new
            end
          end
        end

        it 'serializes embedded objects which respond to #serializable_hash' do
          fresh_class.expose :name, :embedded
          presenter = fresh_class.new(EntitySpec::EmbeddedExampleWithOne.new)
          expect(presenter.serializable_hash).to eq(name: 'abc', embedded: { abc: 'def' })
        end

        it 'serializes embedded arrays of objects which respond to #serializable_hash' do
          fresh_class.expose :name, :embedded
          presenter = fresh_class.new(EntitySpec::EmbeddedExampleWithMany.new)
          expect(presenter.serializable_hash).to eq(name: 'abc', embedded: [{ abc: 'def' }, { abc: 'def' }])
        end

        it 'serializes embedded hashes of objects which respond to #serializable_hash' do
          fresh_class.expose :name, :embedded
          presenter = fresh_class.new(EntitySpec::EmbeddedExampleWithHash.new)
          expect(presenter.serializable_hash).to eq(name: 'abc', embedded: { a: nil, b: { abc: 'def' } })
        end
      end
    end

    describe '#value_for' do
      before do
        fresh_class.class_eval do
          expose :name, :email
          expose :friends, using: self
          expose :computed do |_, options|
            options[:awesome]
          end

          expose :birthday, format_with: :timestamp

          def timestamp(date)
            date.strftime('%m/%d/%Y')
          end

          expose :fantasies, format_with: lambda { |f| f.reverse }
        end
      end

      it 'passes through bare expose attributes' do
        expect(subject.send(:value_for, :name)).to eq attributes[:name]
      end

      it 'instantiates a representation if that is called for' do
        rep = subject.send(:value_for, :friends)
        expect(rep.reject { |r| r.is_a?(fresh_class) }).to be_empty
        expect(rep.first.serializable_hash[:name]).to eq 'Friend 1'
        expect(rep.last.serializable_hash[:name]).to eq 'Friend 2'
      end

      context 'child representations' do
        it 'disables root key name for child representations' do
          module EntitySpec
            class FriendEntity < Grape::Entity
              root 'friends', 'friend'
              expose :name, :email
            end
          end

          fresh_class.class_eval do
            expose :friends, using: EntitySpec::FriendEntity
          end

          rep = subject.send(:value_for, :friends)
          expect(rep).to be_kind_of Array
          expect(rep.reject { |r| r.is_a?(EntitySpec::FriendEntity) }).to be_empty
          expect(rep.first.serializable_hash[:name]).to eq 'Friend 1'
          expect(rep.last.serializable_hash[:name]).to eq 'Friend 2'
        end

        it 'passes through the proc which returns an array of objects with custom options(:using)' do
          module EntitySpec
            class FriendEntity < Grape::Entity
              root 'friends', 'friend'
              expose :name, :email
            end
          end

          fresh_class.class_eval do
            expose :custom_friends, using: EntitySpec::FriendEntity do |user, _opts|
              user.friends
            end
          end

          rep = subject.send(:value_for, :custom_friends)
          expect(rep).to be_kind_of Array
          expect(rep.reject { |r| r.is_a?(EntitySpec::FriendEntity) }).to be_empty
          expect(rep.first.serializable_hash).to eq(name: 'Friend 1', email: 'friend1@example.com')
          expect(rep.last.serializable_hash).to eq(name: 'Friend 2', email: 'friend2@example.com')
        end

        it 'passes through the proc which returns single object with custom options(:using)' do
          module EntitySpec
            class FriendEntity < Grape::Entity
              root 'friends', 'friend'
              expose :name, :email
            end
          end

          fresh_class.class_eval do
            expose :first_friend, using: EntitySpec::FriendEntity do |user, _opts|
              user.friends.first
            end
          end

          rep = subject.send(:value_for, :first_friend)
          expect(rep).to be_kind_of EntitySpec::FriendEntity
          expect(rep.serializable_hash).to eq(name: 'Friend 1', email: 'friend1@example.com')
        end

        it 'passes through the proc which returns empty with custom options(:using)' do
          module EntitySpec
            class FriendEntity < Grape::Entity
              root 'friends', 'friend'
              expose :name, :email
            end
          end

          fresh_class.class_eval do
            expose :first_friend, using: EntitySpec::FriendEntity do |_user, _opts|
            end
          end

          rep = subject.send(:value_for, :first_friend)
          expect(rep).to be_kind_of EntitySpec::FriendEntity
          expect(rep.serializable_hash).to be_nil
        end

        it 'passes through custom options' do
          module EntitySpec
            class FriendEntity < Grape::Entity
              root 'friends', 'friend'
              expose :name
              expose :email, if: { user_type: :admin }
            end
          end

          fresh_class.class_eval do
            expose :friends, using: EntitySpec::FriendEntity
          end

          rep = subject.send(:value_for, :friends)
          expect(rep).to be_kind_of Array
          expect(rep.reject { |r| r.is_a?(EntitySpec::FriendEntity) }).to be_empty
          expect(rep.first.serializable_hash[:email]).to be_nil
          expect(rep.last.serializable_hash[:email]).to be_nil

          rep = subject.send(:value_for, :friends,  user_type: :admin)
          expect(rep).to be_kind_of Array
          expect(rep.reject { |r| r.is_a?(EntitySpec::FriendEntity) }).to be_empty
          expect(rep.first.serializable_hash[:email]).to eq 'friend1@example.com'
          expect(rep.last.serializable_hash[:email]).to eq 'friend2@example.com'
        end

        it 'ignores the :collection parameter in the source options' do
          module EntitySpec
            class FriendEntity < Grape::Entity
              root 'friends', 'friend'
              expose :name
              expose :email, if: { collection: true }
            end
          end

          fresh_class.class_eval do
            expose :friends, using: EntitySpec::FriendEntity
          end

          rep = subject.send(:value_for, :friends,  collection: false)
          expect(rep).to be_kind_of Array
          expect(rep.reject { |r| r.is_a?(EntitySpec::FriendEntity) }).to be_empty
          expect(rep.first.serializable_hash[:email]).to eq 'friend1@example.com'
          expect(rep.last.serializable_hash[:email]).to eq 'friend2@example.com'
        end
      end

      it 'calls through to the proc if there is one' do
        expect(subject.send(:value_for, :computed, awesome: 123)).to eq 123
      end

      it 'returns a formatted value if format_with is passed' do
        expect(subject.send(:value_for, :birthday)).to eq '02/27/2012'
      end

      it 'returns a formatted value if format_with is passed a lambda' do
        expect(subject.send(:value_for, :fantasies)).to eq ['Nessy', 'Double Rainbows', 'Unicorns']
      end

      it 'tries instance methods on the entity first' do
        module EntitySpec
          class DelegatingEntity < Grape::Entity
            root 'friends', 'friend'
            expose :name
            expose :email

            private

            def name
              'cooler name'
            end
          end
        end

        friend = double('Friend', name: 'joe', email: 'joe@example.com')
        rep = EntitySpec::DelegatingEntity.new(friend)
        expect(rep.send(:value_for, :name)).to eq 'cooler name'
        expect(rep.send(:value_for, :email)).to eq 'joe@example.com'
      end

      context 'using' do
        before do
          module EntitySpec
            class UserEntity < Grape::Entity
              expose :name, :email
            end
          end
        end
        it 'string' do
          fresh_class.class_eval do
            expose :friends, using: 'EntitySpec::UserEntity'
          end

          rep = subject.send(:value_for, :friends)
          expect(rep).to be_kind_of Array
          expect(rep.size).to eq 2
          expect(rep.all? { |r| r.is_a?(EntitySpec::UserEntity) }).to be true
        end

        it 'class' do
          fresh_class.class_eval do
            expose :friends, using: EntitySpec::UserEntity
          end

          rep = subject.send(:value_for, :friends)
          expect(rep).to be_kind_of Array
          expect(rep.size).to eq 2
          expect(rep.all? { |r| r.is_a?(EntitySpec::UserEntity) }).to be true
        end
      end
    end

    describe '#documentation' do
      it 'returns an empty hash is no documentation is provided' do
        fresh_class.expose :name

        expect(subject.documentation).to eq({})
      end

      it 'returns each defined documentation hash' do
        doc = { type: 'foo', desc: 'bar' }
        fresh_class.expose :name, documentation: doc
        fresh_class.expose :email, documentation: doc
        fresh_class.expose :birthday

        expect(subject.documentation).to eq(name: doc, email: doc)
      end

      it 'returns each defined documentation hash with :as param considering' do
        doc = { type: 'foo', desc: 'bar' }
        fresh_class.expose :name, documentation: doc, as: :label
        fresh_class.expose :email, documentation: doc
        fresh_class.expose :birthday

        expect(subject.documentation).to eq(label: doc, email: doc)
      end
    end

    describe '#key_for' do
      it 'returns the attribute if no :as is set' do
        fresh_class.expose :name
        expect(subject.class.send(:key_for, :name)).to eq :name
      end

      it 'returns a symbolized version of the attribute' do
        fresh_class.expose :name
        expect(subject.class.send(:key_for, 'name')).to eq :name
      end

      it 'returns the :as alias if one exists' do
        fresh_class.expose :name, as: :nombre
        expect(subject.class.send(:key_for, 'name')).to eq :nombre
      end
    end

    describe '#conditions_met?' do
      it 'only passes through hash :if exposure if all attributes match' do
        exposure_options = { if: { condition1: true, condition2: true } }

        expect(subject.send(:conditions_met?, exposure_options, {})).to be false
        expect(subject.send(:conditions_met?, exposure_options, condition1: true)).to be false
        expect(subject.send(:conditions_met?, exposure_options, condition1: true, condition2: true)).to be true
        expect(subject.send(:conditions_met?, exposure_options, condition1: false, condition2: true)).to be false
        expect(subject.send(:conditions_met?, exposure_options, condition1: true, condition2: true, other: true)).to be true
      end

      it 'looks for presence/truthiness if a symbol is passed' do
        exposure_options = { if: :condition1 }

        expect(subject.send(:conditions_met?, exposure_options, {})).to be false
        expect(subject.send(:conditions_met?, exposure_options,  condition1: true)).to be true
        expect(subject.send(:conditions_met?, exposure_options,  condition1: false)).to be false
        expect(subject.send(:conditions_met?, exposure_options,  condition1: nil)).to be false
      end

      it 'looks for absence/falsiness if a symbol is passed' do
        exposure_options = { unless: :condition1 }

        expect(subject.send(:conditions_met?, exposure_options, {})).to be true
        expect(subject.send(:conditions_met?, exposure_options,  condition1: true)).to be false
        expect(subject.send(:conditions_met?, exposure_options,  condition1: false)).to be true
        expect(subject.send(:conditions_met?, exposure_options,  condition1: nil)).to be true
      end

      it 'only passes through proc :if exposure if it returns truthy value' do
        exposure_options = { if: lambda { |_, opts| opts[:true] } }

        expect(subject.send(:conditions_met?, exposure_options, true: false)).to be false
        expect(subject.send(:conditions_met?, exposure_options, true: true)).to be true
      end

      it 'only passes through hash :unless exposure if any attributes do not match' do
        exposure_options = { unless: { condition1: true, condition2: true } }

        expect(subject.send(:conditions_met?, exposure_options, {})).to be true
        expect(subject.send(:conditions_met?, exposure_options, condition1: true)).to be false
        expect(subject.send(:conditions_met?, exposure_options, condition1: true, condition2: true)).to be false
        expect(subject.send(:conditions_met?, exposure_options, condition1: false, condition2: true)).to be false
        expect(subject.send(:conditions_met?, exposure_options, condition1: true, condition2: true, other: true)).to be false
        expect(subject.send(:conditions_met?, exposure_options, condition1: false, condition2: false)).to be true
      end

      it 'only passes through proc :unless exposure if it returns falsy value' do
        exposure_options = { unless: lambda { |_, options| options[:true] == true } }

        expect(subject.send(:conditions_met?, exposure_options, true: false)).to be true
        expect(subject.send(:conditions_met?, exposure_options, true: true)).to be false
      end
    end

    describe '::DSL' do
      subject { Class.new }

      it 'creates an Entity class when called' do
        expect(subject).not_to be_const_defined :Entity
        subject.send(:include, Grape::Entity::DSL)
        expect(subject).to be_const_defined :Entity
      end

      context 'pre-mixed' do
        before { subject.send(:include, Grape::Entity::DSL) }

        it 'is able to define entity traits through DSL' do
          subject.entity do
            expose :name
          end

          expect(subject.entity_class.exposures).not_to be_empty
        end

        it 'is able to expose straight from the class' do
          subject.entity :name, :email
          expect(subject.entity_class.exposures.size).to eq 2
        end

        it 'is able to mix field and advanced exposures' do
          subject.entity :name, :email do
            expose :third
          end
          expect(subject.entity_class.exposures.size).to eq 3
        end

        context 'instance' do
          let(:instance) { subject.new }

          describe '#entity' do
            it 'is an instance of the entity class' do
              expect(instance.entity).to be_kind_of(subject.entity_class)
            end

            it 'has an object of itself' do
              expect(instance.entity.object).to eq instance
            end

            it 'instantiates with options if provided' do
              expect(instance.entity(awesome: true).options).to eq(awesome: true)
            end
          end
        end
      end
    end
  end
end