diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 000000000..774aa4d69
Binary files /dev/null and b/.DS_Store differ
diff --git a/.gitignore b/.gitignore
index 5e1422c9c..964590134 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,6 +9,7 @@
 /test/tmp/
 /test/version_tmp/
 /tmp/
+/lib/main.rb
 
 # Used by dotenv library to load environment variables.
 # .env
diff --git a/lib/date_range.rb b/lib/date_range.rb
new file mode 100644
index 000000000..bd78cbedf
--- /dev/null
+++ b/lib/date_range.rb
@@ -0,0 +1,25 @@
+module Hotel
+  class DateRange
+    attr_reader :start_date, :end_date
+
+    def initialize(start_date:, end_date:)
+      #TODO: validate dates' input
+      #TODO: add defaults (for example, one year from/before Date.today)
+      @start_date = Date.parse(start_date)
+      @end_date = Date.parse(end_date)      
+
+      raise ArgumentError.new("End date cannot be equal to or come before start date.") if @end_date <= @start_date
+    end
+
+    def overlap?(date_range)
+      raise ArgumentError.new("Must provide a date range.") unless date_range.is_a? DateRange 
+
+      #TODO: efficient date checking (first compare years? months?)
+      start_date < date_range.end_date && end_date > date_range.start_date
+    end
+
+    def nights
+      (end_date - start_date).to_i
+    end
+  end
+end
\ No newline at end of file
diff --git a/lib/reservation.rb b/lib/reservation.rb
new file mode 100644
index 000000000..c3272df92
--- /dev/null
+++ b/lib/reservation.rb
@@ -0,0 +1,22 @@
+require "date"
+
+module Hotel
+  class Reservation
+    attr_reader :date_range, :room_id, :rate
+
+    def initialize(room_id: , start_date:, end_date:, rate: :default)
+      unless (rate == :default || rate.respond_to?(:>) && rate >= 0)
+        raise ArgumentError.new("Invalid rate.") 
+      end
+
+      @date_range = DateRange.new(start_date: start_date, end_date: end_date)
+      @room_id = room_id
+      @rate = (rate == :default) ? 200 : rate
+    end
+
+    def cost
+      date_range.nights * rate
+    end
+  end
+end
+
diff --git a/lib/reservation_desk.rb b/lib/reservation_desk.rb
new file mode 100644
index 000000000..5c656118a
--- /dev/null
+++ b/lib/reservation_desk.rb
@@ -0,0 +1,119 @@
+module Hotel
+  class ReservationDesk
+  # Class responsibility: to organize reservations across hotel
+    attr_reader :room_num, :rooms, :reservations, :blocks
+
+    def initialize(room_num: 20)
+      @room_num = room_num
+      @rooms = make_rooms
+      @blocks = {}
+    end
+
+    def find_room_by_id(id)
+      rooms.find {|room| room.id == id}
+    end
+
+    def find_reservations(room_id: nil , start_date: , end_date: )
+      date_range = DateRange.new(start_date: start_date, end_date: end_date)
+
+      if room_id 
+        room = rooms.find { |room| room.id == room_id}
+        return nil if room == nil
+        reservations = room.select_reservations(date_range)
+      else
+        reservations = []
+        rooms.each do |room|
+          room_reservations = room.select_reservations(date_range)
+          reservations += room_reservations
+        end
+      end
+      return reservations
+    end
+
+    def find_available_rooms(start_date:, end_date:)
+      available_rooms = []
+      rooms.each do |room|
+        available_rooms << room if room.available?(start_date: start_date, end_date: end_date)
+      end
+      return available_rooms.empty? ? nil : available_rooms
+    end
+
+    def make_reservation(room_id: nil, start_date:, end_date:, rate: :default)
+      if room_id 
+        room = find_room_by_id(room_id)
+        raise ArgumentError.new("Invalid room ID.") if room == nil
+      else
+        room = find_available_rooms(start_date: start_date, end_date: end_date)[0]
+        raise StandardError.new("No rooms available for these dates.") if room == nil
+      end
+      room.reserve(start_date: start_date, end_date: end_date, rate: rate)
+    end
+
+    def make_block(room_ids:, start_date:, end_date:, rate: :default)
+      #TODO: add no rooms given scenario
+      raise ArgumentError.new("Blocks should contain 2-5 rooms.") if (room_ids.length > 5 || room_ids.length < 2)
+
+      block_id = create_block(start_date: start_date, end_date: end_date)
+      room_ids.each do |id|
+        room = find_room_by_id(id)
+        raise ArgumentError.new("Invalid room ID.") if room == nil
+        room.reserve(start_date: start_date, end_date: end_date, block: block_id, rate: rate)
+        blocks[block_id][:rooms] << room
+      end
+    end
+
+    def reserve_from_block(room_id: , block_id: )
+      raise ArgumentError.new("Invalid block ID.") unless blocks[block_id]
+      
+      blocks[block_id][:rooms].each do |room|
+        if room.id == room_id
+          start_date = blocks[block_id][:date_range][0]
+          end_date = blocks[block_id][:date_range][1] 
+          unless room.reserved?(start_date: start_date, end_date: end_date)
+            room.block_participation.each do |block_part|
+              if block_part.date_range.start_date == Date.parse(start_date)
+                room.reservations << block_part
+                return true
+              end
+            end
+          end
+          raise StandardError.new("This room has already been reserved.")
+        end
+      end
+      raise ArgumentError.new("Invalid room ID.")
+    end
+
+    def check_block_availability(block_id)
+      raise ArgumentError.new("Invalid block ID.") unless blocks[block_id]
+      available_rooms = []
+      start_date = blocks[block_id][:date_range][0]
+      end_date = blocks[block_id][:date_range][1]
+
+      blocks[block_id][:rooms].each do |room|
+        available_rooms << room unless room.reserved?(start_date: start_date, end_date: end_date)
+      end
+      return available_rooms
+    end
+    
+    private
+    def make_rooms
+      rooms = []
+      room_num.times do |i|
+        rooms << Room.new(i+1)
+      end
+      return rooms
+    end
+
+    def generate_block_id
+      blocks.length + 1
+    end
+
+    def create_block(start_date:, end_date:)
+      block_id = generate_block_id
+      blocks[block_id] = {}
+      blocks[block_id][:date_range] = [start_date, end_date]
+      blocks[block_id][:rooms] = []
+      return block_id
+    end
+  end
+end
\ No newline at end of file
diff --git a/lib/room.rb b/lib/room.rb
new file mode 100644
index 000000000..e220d0e0e
--- /dev/null
+++ b/lib/room.rb
@@ -0,0 +1,64 @@
+module Hotel
+
+  class Room
+  # Class responsibility: to reserve individual rooms
+    attr_reader :id, :reservations, :block_participation
+
+    def initialize(id)
+      @id = id
+      @reservations = []
+      @block_participation = []
+    end
+
+    # available? helper method / public interface
+    def reserved?(start_date:, end_date:)
+      date_range = DateRange.new(start_date: start_date, end_date: end_date)
+      reservations.each do |reservation|
+        if reservation.date_range.overlap? (date_range)
+          return true
+        end
+      end
+      return false
+    end
+
+    # available? helper method / public interface
+    def in_block?(start_date:, end_date:)
+      date_range = DateRange.new(start_date: start_date, end_date: end_date)
+      block_participation.each do |block_reservation|
+        if block_reservation.date_range.overlap? (date_range)
+          return true
+        end
+      end
+      return false
+    end
+
+    def available?(start_date:, end_date:)
+      (reserved?(start_date: start_date, end_date: end_date) || in_block?(start_date: start_date, end_date: end_date)) ? false : true
+    end
+
+    def reserve(start_date:, end_date:, block: nil, rate: :default)
+      unless available?(start_date: start_date, end_date: end_date) 
+        raise StandardError.new("Room #{id} is unavailabe for requested dates.") 
+      end
+      reservation = new_reservation(start_date: start_date, end_date: end_date, rate: rate) 
+      block ? add_block_participation(reservation) : add_reservation(reservation)
+    end
+
+    def select_reservations(date_range)
+      reservations.select { |reservation| reservation.date_range.overlap? (date_range)}
+    end
+
+    private
+      def new_reservation(start_date:, end_date:, rate: :default) 
+        reservation = Reservation.new(room_id: id, start_date: start_date, end_date: end_date, rate: rate)
+      end
+
+      def add_reservation(reservation)
+        reservations << reservation
+      end  
+
+      def add_block_participation(reservation)
+        block_participation << reservation
+      end
+  end
+end
diff --git a/refactors.txt b/refactors.txt
new file mode 100644
index 000000000..ea4cf9548
--- /dev/null
+++ b/refactors.txt
@@ -0,0 +1,17 @@
+1. Consider adding Block Class instead of hash structure in ReservationDesk
+- ReservationDesk will have a blocks array of Block objects.
+- ReservationDesk will have find_block_by_id method.
+- Block object will have block_id, rooms (array of Room objects), date_range variables.
+- Block object will have reserve_from_block and check_room_availability methods which will be called from inside current ReservationDesk methods.
+
+2. Add date input validation.
+
+3. Add defaults for start and end dates.
+(gives functionality to select all reservations from/until specific date)
+
+4. Find a more efficient way to compare dates.
+(sort and compare years/months first?..)
+
+5. Consider moving away from having start and end_date as arguments towards using date_range.
+
+6. Implement "no rooms given" scenario for make_block.
\ No newline at end of file
diff --git a/test/date_range_test.rb b/test/date_range_test.rb
new file mode 100644
index 000000000..0d39bc64f
--- /dev/null
+++ b/test/date_range_test.rb
@@ -0,0 +1,76 @@
+require_relative "test_helper"
+
+describe "DateRange class" do
+  describe "DateRange instatiation" do
+    # before do
+    #   date_range = Hotel::DateRange.new()
+    # end
+    it "is an instance of DateRange" do
+      expect(Hotel::DateRange.new(start_date: "2020-3-1", end_date: "2020-3-10")).must_be_kind_of Hotel::DateRange
+    end
+
+    it "converts its start_date and end_date attributes to Date objects" do
+      date_range = Hotel::DateRange.new(start_date: "2020-3-1", end_date: "2020-3-10")
+      expect(date_range.start_date).must_be_kind_of Date
+      expect(date_range.end_date).must_be_kind_of Date
+    end 
+
+    it "raises an ArgumentError if end_date is equal to or comes before start_date" do
+      expect {Hotel::DateRange.new(start_date: "2020-3-1", end_date: "2020-2-10")}.must_raise ArgumentError
+      expect {Hotel::DateRange.new(start_date: "2020-3-1", end_date: "2020-3-1")}.must_raise ArgumentError
+    end
+
+    # TODO
+    # it "can be instantiated with no arguments" do
+    #   expect(Hotel::DateRange.new()).must_be_kind_of Hotel::DateRange
+    # end
+  end
+
+  describe "overlap?" do
+    let (:date_range) {
+      Hotel::DateRange.new(start_date: "2020-3-1", end_date: "2020-3-20")
+    }
+
+    it "expects a DateRange as an argument" do
+      expect {date_range.overlap?(50)}.must_raise ArgumentError
+    end
+
+    it "returns true if the dates overlap and false if not" do
+      # TODO: each one should be a new test?
+      second_date_range = Hotel::DateRange.new(start_date: "2020-3-2", end_date: "2020-3-10")
+      expect(date_range.overlap?(second_date_range)).must_equal true
+
+      third_date_range = Hotel::DateRange.new(start_date: "2020-3-13", end_date: "2020-3-25")
+      expect(date_range.overlap?(third_date_range)).must_equal true
+
+      forth_date_range = Hotel::DateRange.new(start_date: "2020-2-10", end_date: "2020-2-26")
+      expect(date_range.overlap?(forth_date_range)).must_equal false
+
+      fifth_date_range = Hotel::DateRange.new(start_date: "2020-3-23", end_date: "2020-3-25")
+      expect(date_range.overlap?(fifth_date_range)).must_equal false
+
+      six_date_range = Hotel::DateRange.new(start_date: "2020-3-20", end_date: "2020-3-21")
+      expect(date_range.overlap?(six_date_range)).must_equal false
+    end
+
+    # TODO:
+    # it "expects a DateRange provided as an argument to have start_date and end_date rather than nil" do
+    #   other_date_range_1 = Hotel::DateRange.new(end_date: "2020-5-10")
+    #   expect {date_range.overlap? (other_date_range_1)}.must_raise ArgumentError
+
+    #   other_date_range_2 = Hotel::DateRange.new(start_date: "2020-5-10")
+    #   expect {date_range.overlap? (other_date_range_2)}.must_raise ArgumentError
+    # end
+  end
+
+  describe "nights" do
+    it "calculates the number of nights for the date range" do
+      date_range = Hotel::DateRange.new(start_date: "2020-3-1", end_date: "2020-3-10")
+      expect(date_range.nights).must_equal 9
+
+      date_range = Hotel::DateRange.new(start_date: "2020-3-1", end_date: "2020-3-2")
+      expect(date_range.nights).must_equal 1
+    end
+  end
+
+end
\ No newline at end of file
diff --git a/test/reservation_desk_test.rb b/test/reservation_desk_test.rb
new file mode 100644
index 000000000..34b25e8da
--- /dev/null
+++ b/test/reservation_desk_test.rb
@@ -0,0 +1,317 @@
+require_relative "test_helper"
+
+describe "ReservationDesk class" do
+  before do
+    @reservation_desk = Hotel::ReservationDesk.new()
+  end
+
+  describe "ReservationDesk instantiation" do
+    it "is an instance of ReservationDesk" do
+      expect(@reservation_desk).must_be_kind_of Hotel::ReservationDesk
+    end
+  end
+
+  describe "rooms" do
+    it "returns an array" do
+      expect(@reservation_desk.rooms).must_be_kind_of Array
+    end
+
+    it "returns an array of Rooms" do
+      expect(@reservation_desk.rooms[0]).must_be_kind_of Hotel::Room
+      expect(@reservation_desk.rooms.last).must_be_kind_of Hotel::Room
+    end
+
+    it "includes 20 rooms by default" do
+      expect(@reservation_desk.rooms.length).must_equal 20
+    end
+
+    it "the first room has an id of 1" do
+      expect(@reservation_desk.rooms[0].id).must_equal 1
+    end
+
+    it "the last room has an id which is equal to the number of rooms" do
+      reservation_desk = Hotel::ReservationDesk.new(room_num: 134)
+      expect(reservation_desk.rooms.last.id).must_equal 134
+    end
+  end
+
+  describe "find_room_by_id" do
+    it "returns an instanse of Room" do
+      expect(@reservation_desk.find_room_by_id(2)).must_be_kind_of Hotel::Room
+    end
+
+    it "returns a Room with a matching ID" do
+      expect(@reservation_desk.find_room_by_id(2).id).must_equal 2
+    end
+
+    it "returns nill if there is no Room with a matching ID" do
+      assert_nil @reservation_desk.find_room_by_id(20000000)
+   end
+  end
+
+  describe "find_reservations" do
+    before do
+      @reservation_desk.rooms[0].reserve(start_date: "2020-3-1", end_date: "2020-3-5")
+      @reservation_desk.rooms[1].reserve(start_date: "2020-3-1", end_date: "2020-3-10")
+      @reservation_desk.rooms[2].reserve(start_date: "2020-3-1", end_date: "2020-3-25")
+      @reservation_desk.rooms[0].reserve(start_date: "2020-3-10", end_date: "2020-3-15")
+
+    end
+
+    it "returns an array" do
+      result = @reservation_desk.find_reservations(room_id: 1, start_date: "2020-3-1", end_date: "2020-3-17")
+      expect(result).must_be_kind_of Array
+    end
+
+    it "returns an array of reservations" do
+      result = @reservation_desk.find_reservations(room_id: 1, start_date: "2020-3-1", end_date: "2020-3-17")
+      expect(result[0]).must_be_kind_of Hotel::Reservation
+    end
+
+    it "ID provided: returns nil if room ID doesn't exist" do
+      assert_nil @reservation_desk.find_reservations(room_id: 100000, start_date: "2020-3-1", end_date: "2020-3-17")
+    end
+
+    it "ID provided: returns reservations for requested dates" do
+      result_1 = @reservation_desk.find_reservations(room_id: 1, start_date: "2020-3-1", end_date: "2020-3-17")
+      expect(result_1.length).must_equal 2
+      result_2 = @reservation_desk.find_reservations(room_id: 1, start_date: "2020-3-1", end_date: "2020-3-10")
+      expect(result_2.length).must_equal 1
+      result_3 = @reservation_desk.find_reservations(room_id: 1, start_date: "2020-3-3", end_date: "2020-3-8")
+      expect(result_3.length).must_equal 1
+      result_4 = @reservation_desk.find_reservations(room_id: 1, start_date: "2020-3-11", end_date: "2020-3-13")
+      expect(result_4.length).must_equal 1
+    end
+
+    it "No ID provided: returns reservations for specific dates for all rooms" do
+      @reservation_desk.rooms[3].reserve(start_date: "2020-3-1", end_date: "2020-3-5")
+      @reservation_desk.rooms[4].reserve(start_date: "2020-3-10", end_date: "2020-3-15")
+      @reservation_desk.rooms[5].reserve(start_date: "2020-3-20", end_date: "2020-3-25")
+      @reservation_desk.rooms[6].reserve(start_date: "2020-5-20", end_date: "2020-5-25")
+
+      result = @reservation_desk.find_reservations(start_date: "2020-3-1", end_date: "2020-3-30")
+      expect(result.length).must_equal 7
+    end
+
+    it "takes into account reservertions from a block" do
+      @reservation_desk.make_block(room_ids:[7, 8, 9], start_date: "2020-3-4", end_date: "2020-3-8")
+      @reservation_desk.reserve_from_block(block_id: 1, room_id: 9)
+
+      result = @reservation_desk.find_reservations(room_id: 9, start_date: "2020-3-1", end_date: "2020-3-30")
+      expect(result.length).must_equal 1
+
+      result_2 = @reservation_desk.find_reservations(start_date: "2020-3-1", end_date: "2020-3-30")
+      expect(result_2.length).must_equal 5
+    end
+
+    it "No ID provided: returns empty array if there are no reservations for the room/dates" do
+      result = @reservation_desk.find_reservations(room_id: 1, start_date: "2020-4-1", end_date: "2020-4-17")
+      expect(result.length).must_equal 0
+    end
+  end
+
+  describe "find_available_rooms" do
+    before do
+      @reservation_desk.rooms[0].reserve(start_date: "2020-3-1", end_date: "2020-3-5")
+      @reservation_desk.rooms[1].reserve(start_date: "2020-3-1", end_date: "2020-3-10")
+      @reservation_desk.rooms[2].reserve(start_date: "2020-3-1", end_date: "2020-3-25")
+
+      @request = @reservation_desk.find_available_rooms(start_date: "2020-2-27", end_date: "2020-4-2")
+    end
+
+    it "returns an Array" do
+      expect(@request).must_be_kind_of Array
+    end
+
+    it "returns an Array of Rooms" do
+      expect(@request[0]).must_be_kind_of Hotel::Room
+    end
+
+    it "returns an array of Rooms which don't have Reservations for requested dates" do
+      expect(@request.length).must_equal 17
+      expect(@request[0].id).must_equal 4
+    end
+
+    it "returns nil if there are no Rooms available for requested dates" do
+      @reservation_desk.rooms.each do |room|
+        room.reserve(start_date: "2020-6-1", end_date: "2020-6-30")
+      end
+      search = @reservation_desk.find_available_rooms(start_date: "2020-6-5", end_date: "2020-6-10")
+      assert_nil search
+    end
+  end
+
+  describe "make_reservation" do
+    it "ID provided: makes a new reservation and add it into the Room's reservations array" do
+      @reservation_desk.make_reservation(room_id: 5, start_date: "2020-5-5", end_date: "2020-5-7")
+      @reservation_desk.make_reservation(room_id: 5, start_date: "2020-6-5", end_date: "2020-6-7")
+      expect(@reservation_desk.rooms[4].reservations.length).must_equal 2
+      expect(@reservation_desk.rooms[4].available?(start_date: "2020-5-5", end_date: "2020-5-6")).must_equal false
+    end
+
+    it "ID provided: Raises an ArgumentError if ID is invalid" do
+      expect {
+        @reservation_desk.make_reservation(room_id: 999999, start_date: "2020-5-5", end_date: "2020-5-7")
+      }.must_raise ArgumentError
+    end
+
+    it "No ID provided: reserves the first available room down the list for requested dates" do
+      @reservation_desk.rooms[0].reserve(start_date: "2020-3-1", end_date: "2020-3-5")
+      @reservation_desk.rooms[1].reserve(start_date: "2020-3-1", end_date: "2020-3-10")
+
+      @request = @reservation_desk.make_reservation(start_date: "2020-3-4", end_date: "2020-3-15")
+      expect(@reservation_desk.rooms[2].reservations.length).must_equal 1
+      expect(@reservation_desk.rooms[2].available?(start_date: "2020-3-1", end_date: "2020-3-5")).must_equal false
+    end
+
+    it "No ID provided: raises an Exception if no rooms are available for requested dates" do
+      20.times do
+        @reservation_desk.make_reservation(start_date: "2020-6-1", end_date: "2020-6-30")
+      end
+      expect {
+        @reservation_desk.make_reservation(start_date: "2020-6-1", end_date: "2020-6-30")
+      }.must_raise StandardError
+    end
+
+    it "reserves a room at a default rate if no other specified" do
+      @reservation_desk.make_reservation(room_id: 1, start_date: "2020-5-5", end_date: "2020-5-7")
+      rate = @reservation_desk.rooms[0].reservations[0].rate
+      expect(rate).must_equal 200
+    end
+
+    it "reserves a room at a specified rate" do
+      @reservation_desk.make_reservation(room_id: 1, start_date: "2020-5-5", end_date: "2020-5-7", rate: 310.05)
+      rate = @reservation_desk.rooms[0].reservations[0].rate
+      expect(rate).must_equal 310.05
+    end
+  end
+
+  describe "make_block" do
+    it "Room IDs provided: it creates Reservations and adds them to requested rooms' block_participation array" do
+      @reservation_desk.make_block(room_ids: [1, 2, 3], start_date: "2020-9-1", end_date: "2020-9-10")
+      expect(@reservation_desk.rooms[0].block_participation.length).must_equal 1
+      expect(@reservation_desk.rooms[1].block_participation.length).must_equal 1
+      expect(@reservation_desk.rooms[2].block_participation.length).must_equal 1
+      expect(@reservation_desk.rooms[3].block_participation.length).must_equal 0
+    end
+
+    it "Rooms IDs provided: it adds block information to the block hash" do
+      @reservation_desk.make_block(room_ids: [1, 2, 3], start_date: "2020-9-1", end_date: "2020-9-10")
+      expect(@reservation_desk.blocks.length).must_equal 1
+      expect(@reservation_desk.blocks[1][:rooms].length).must_equal 3
+      expect(@reservation_desk.blocks[1][:rooms][0]).must_be_kind_of Hotel::Room
+    end
+
+    it "Rooms IDs provided: raises an ArgumentError if any of IDs are invalid" do
+      expect {
+        @reservation_desk.make_block(room_ids: [1, 2, "love"], start_date: "2020-9-1", end_date: "2020-9-10")
+      }.must_raise ArgumentError
+    end
+
+    it "Rooms IDs provided: raises ArgumentError if the room_ids array includes less than 2 rooms" do
+      expect {
+        @reservation_desk.make_block(room_ids: [1], start_date: "2020-9-1", end_date: "2020-9-10")
+      }.must_raise ArgumentError
+    end
+
+    it "Rooms IDs provided: raises ArgumentError if the room_ids array includes more than 5 rooms" do
+      expect {
+        @reservation_desk.make_block(room_ids: [1, 2, 3, 4, 5, 6], start_date: "2020-9-1", end_date: "2020-9-10")
+      }.must_raise ArgumentError
+    end
+
+    it "Rooms IDs provided: it raises an Exception if any of the rooms are unavailable on requested dates" do
+      @reservation_desk.make_reservation(start_date: "2020-10-1", end_date: "2020-10-5")
+      
+      expect {
+        @reservation_desk.make_block(room_ids: [4, 5, 6, 7, 1], start_date: "2020-10-2", end_date: "2020-10-16")
+      }.must_raise StandardError
+
+      @reservation_desk.make_block(room_ids: [1, 2, 3], start_date: "2020-9-1", end_date: "2020-9-10")
+
+      expect {
+        @reservation_desk.make_block(room_ids: [4, 5, 6, 7, 1], start_date: "2020-9-2", end_date: "2020-9-5")
+      }.must_raise StandardError
+    end
+
+    it "creates reservations with default rate if no discount specified" do
+      @reservation_desk.make_block(room_ids: [1, 2, 3], start_date: "2020-9-1", end_date: "2020-9-10")
+      rate = @reservation_desk.rooms[0].block_participation[0].rate
+      expect(rate).must_equal 200
+    end
+
+    it "creates reservations with a different rate if specified" do
+      @reservation_desk.make_block(room_ids: [1, 2, 3], start_date: "2020-9-1", end_date: "2020-9-10", rate: 150)
+      rate = @reservation_desk.rooms[0].block_participation[0].rate
+      expect(rate).must_equal 150
+    end
+  end
+
+  describe "reserve_from_block" do
+    before do
+      @reservation_desk.make_block(room_ids: [1, 2, 3, 4], start_date: "2020-9-1", end_date: "2020-9-10")
+      @reservation = @reservation_desk.reserve_from_block(room_id: 2, block_id: 1)
+    end
+    
+    it "returns true if reservation was successful" do
+      expect(@reservation).must_equal true
+    end
+
+    it "raises ArgumentError if room ID was not valid or wasn't part of the block" do
+      expect {
+        @reservation_desk.reserve_from_block(room_id: 6, block_id: 1)
+      }.must_raise ArgumentError
+    end
+
+    it "raises ArgumentError if the block ID is invalid" do
+      expect {
+        @reservation_desk.reserve_from_block(room_id: 6, block_id: 1000)
+      }.must_raise ArgumentError
+    end
+
+    it "raises StandardError if the room has already been reserved" do
+      expect {
+        @reservation_desk.reserve_from_block(room_id: 2, block_id: 1)
+      }.must_raise StandardError
+    end
+
+    it "adds the original block reservation for the room to reservations array" do
+      expect(@reservation_desk.rooms[0].reservations.length).must_equal 0
+      @reservation_desk.reserve_from_block(room_id: 1, block_id: 1)
+      expect(@reservation_desk.rooms[0].reservations.length).must_equal 1
+    end
+  end
+
+  describe "check_block_availability" do
+    before do
+      @reservation_desk.make_block(room_ids: [1, 2, 3, 4, 5], start_date: "2020-9-1", end_date: "2020-9-10")
+      @reservation_desk.reserve_from_block(room_id: 3, block_id: 1)
+    end
+
+    it "returns an Array" do
+      expect(@reservation_desk.check_block_availability(1)).must_be_kind_of Array
+    end
+
+    it "returns an array of unreserved rooms in requested block" do
+      expect(@reservation_desk.check_block_availability(1).length).must_equal 4
+    end
+
+    it "returns empty array if no rooms are available" do
+      @reservation_desk.reserve_from_block(room_id: 1, block_id: 1)
+      @reservation_desk.reserve_from_block(room_id: 2, block_id: 1)
+      @reservation_desk.reserve_from_block(room_id: 4, block_id: 1)
+      @reservation_desk.reserve_from_block(room_id: 5, block_id: 1)
+      expect(@reservation_desk.check_block_availability(1).empty?).must_equal true
+    end
+
+    it "throws an ArgumentError if there is no block with a given ID" do
+      expect { 
+        @reservation_desk.reserve_from_block(room_id: 1, block_id: 2)
+      }.must_raise ArgumentError
+
+      expect { 
+        @reservation_desk.reserve_from_block(room_id: 1, block_id: "Nataliya")
+      }.must_raise ArgumentError
+    end
+  end
+end
\ No newline at end of file
diff --git a/test/reservation_test.rb b/test/reservation_test.rb
new file mode 100644
index 000000000..19ec211e1
--- /dev/null
+++ b/test/reservation_test.rb
@@ -0,0 +1,63 @@
+require_relative "test_helper"
+
+describe "Reservation class" do
+  before do
+    @room_id = 1
+    @start_date = "2020-4-1"
+    @end_date = "2020-4-5"
+    @reservation = Hotel::Reservation.new(room_id: @room_id, start_date: @start_date, end_date: @end_date)
+  end
+
+  describe "Reservation instatiation" do
+    it "is an instance of reservation" do
+      expect(@reservation).must_be_kind_of Hotel::Reservation
+    end
+
+    it "has date_range variable which holds an instance of DateRange" do
+      expect(@reservation.date_range).must_be_kind_of Hotel::DateRange
+    end
+
+    it "has a rate of 200 if no argument provided" do
+      expect(@reservation.rate).must_equal 200
+    end
+
+    it "can be instantiated with a different rate" do
+      reservation = Hotel::Reservation.new(room_id: 2, start_date: "2020-5-1", end_date: "2020-5-6", rate: 210)
+      expect(reservation.rate).must_equal 210
+    end
+
+    it "zero rate is fine" do
+      reservation = Hotel::Reservation.new(room_id: 2, start_date: "2020-5-1", end_date: "2020-5-6", rate: 0)
+      expect(reservation.rate).must_equal 0
+    end
+
+    it "raises an Argument error if rate provided is invalid (not a number)" do
+      expect {
+        reservation = Hotel::Reservation.new(room_id: 2, start_date: "2020-5-1", end_date: "2020-5-6", rate: "Cody")
+      }.must_raise ArgumentError
+    end
+
+    it "raises an Argument error if rate provided is smaller than 0" do
+      expect {
+        reservation = Hotel::Reservation.new(room_id: 2, start_date: "2020-5-1", end_date: "2020-5-6", rate: -1)
+      }.must_raise ArgumentError
+    end
+  end
+
+  describe "cost" do
+    it "returns an integer" do
+      expect(@reservation.cost).must_be_kind_of Integer
+    end
+
+    it "calculates cost at Reservation's rate" do
+      expect(@reservation.cost).must_equal 800
+
+      room_id = 1
+      start_date = "2020-5-1"
+      end_date = "2020-5-5"
+      rate = 180
+      reservation = Hotel::Reservation.new(room_id: room_id, start_date: start_date, end_date: end_date, rate: rate)
+      expect(reservation.cost).must_equal 720
+    end
+  end
+end
\ No newline at end of file
diff --git a/test/room_test.rb b/test/room_test.rb
new file mode 100644
index 000000000..8643ddb02
--- /dev/null
+++ b/test/room_test.rb
@@ -0,0 +1,116 @@
+require_relative 'test_helper'
+
+describe "Room Class" do
+  describe "Room instantiation" do
+    before do
+      @room = Hotel::Room.new(1)
+    end
+
+    it "is an instance of Room" do
+      expect(@room).must_be_kind_of Hotel::Room
+    end
+
+    it "stores an id" do
+      expect(@room.id).must_equal 1
+    end
+
+    it "starts with an empty array for reservations" do
+      expect(@room.reservations).must_be_kind_of Array
+      expect(@room.reservations.empty?).must_equal true
+    end
+
+    it "starts with an empty array for block participation" do
+      expect(@room.block_participation).must_be_kind_of Array
+      expect(@room.block_participation.empty?).must_equal true
+    end
+  end
+
+  describe "reserved?" do
+    before do
+      @room = Hotel::Room.new(1)
+      @room.reserve(start_date: "2020-3-1", end_date: "2020-3-10")
+    end
+
+    it "returns true if the room is reserved for requested dates" do
+      expect(@room.reserved?(start_date: "2020-3-2", end_date: "2020-3-25")).must_equal true
+    end
+
+    it "returns false if the room is not reserved for requested dates" do
+      expect(@room.reserved?(start_date: "2020-3-22", end_date: "2020-3-25")).must_equal false
+    end
+  end
+
+  describe "in_block?" do
+    before do
+      @room = Hotel::Room.new(1)
+      @room.reserve(start_date: "2020-3-1", end_date: "2020-3-10", block: 2)
+    end
+
+    it "returns true if the room is in a block for requested dates" do
+      expect(@room.in_block?(start_date: "2020-3-2", end_date: "2020-3-25")).must_equal true
+    end
+
+    it "returns false if the room is not in a block for requested dates" do
+      expect(@room.in_block?(start_date: "2020-3-22", end_date: "2020-3-25")).must_equal false
+    end
+  end
+
+  describe "available?" do
+    before do
+      @room = Hotel::Room.new(1)
+      @room.reserve(start_date: "2020-3-1", end_date: "2020-3-10")
+    end
+
+    it "returns true if the room is available for requested dates" do
+      expect(@room.available?(start_date: "2020-3-22", end_date: "2020-3-25")).must_equal true
+    end
+
+    it "returns false if the room is unavailable for requested dates" do
+      expect(@room.available?(start_date: "2020-3-2", end_date: "2020-3-5")).must_equal false
+    end
+  end
+
+  describe "reserve" do
+    it "creates a new reservation and add it to the Room's reservations array" do
+      @room = Hotel::Room.new(10)
+      @room.reserve(start_date: "2020-3-1", end_date: "2020-3-10")
+      expect(@room.reservations.length).must_equal 1
+      expect(@room.reservations[0]).must_be_kind_of Hotel::Reservation
+      expect(@room.reservations[0].room_id).must_equal 10
+    end
+
+    it "reserves a room at default rate if no other specified" do
+      room = Hotel::Room.new(10)
+      room.reserve(start_date: "2020-3-1", end_date: "2020-3-10")
+      rate = room.reservations[0].rate
+      expect(rate).must_equal 200
+    end
+
+    it "reserves room at a specified rate" do
+      room = Hotel::Room.new(10)
+      room.reserve(start_date: "2020-3-1", end_date: "2020-3-10", rate: 339.99)
+      rate = room.reservations[0].rate
+      expect(rate).must_equal 339.99
+    end
+  end
+
+  describe "select_reservations" do
+    before do
+      @room = Hotel::Room.new(10)
+      @room.reserve(start_date: "2020-3-1", end_date: "2020-3-10")
+      @room.reserve(start_date: "2020-3-12", end_date: "2020-3-13")
+      @room.reserve(start_date: "2020-3-15", end_date: "2020-3-20")
+      
+    end
+    it "returnes reservations which match requested date range" do
+      date_range = Hotel::DateRange.new(start_date: "2020-3-1", end_date: "2020-3-25")
+      expect(@room.select_reservations(date_range).length).must_equal 3
+    end
+
+    it "returns empty array if no reservations were made for requested dates" do
+      date_range = Hotel::DateRange.new(start_date: "2020-4-1", end_date: "2020-4-25")
+      expect(@room.select_reservations(date_range).empty?).must_equal true
+    end
+  end
+end
+
diff --git a/test/test_helper.rb b/test/test_helper.rb
index c3a7695cf..4896bd827 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -1,4 +1,7 @@
-# Add simplecov
+require 'simplecov'
+SimpleCov.start do
+  add_filter 'test/'
+end
 require "minitest"
 require "minitest/autorun"
 require "minitest/reporters"
@@ -6,3 +9,7 @@
 Minitest::Reporters.use! Minitest::Reporters::SpecReporter.new
 
 # require_relative your lib files here!
+require_relative "../lib/room"
+require_relative "../lib/reservation_desk"
+require_relative "../lib/reservation"
+require_relative "../lib/date_range"
\ No newline at end of file