diff --git a/Gemfile b/Gemfile
index de82ade..1a7a0f2 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,6 +2,3 @@ source "https://rubygems.org"
 
 # Specify your gem's dependencies in unitsml.gemspec
 gemspec
-
-gem "rake", "~> 12.0"
-gem "rspec", "~> 3.0"
diff --git a/Gemfile.lock b/Gemfile.lock
index 950f62e..279f334 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -6,7 +6,20 @@ PATH
 GEM
   remote: https://rubygems.org/
   specs:
+    ast (2.4.2)
+    byebug (11.1.3)
+    coderay (1.1.3)
     diff-lcs (1.4.4)
+    docile (1.3.5)
+    method_source (0.9.2)
+    parallel (1.20.1)
+    parser (3.0.0.0)
+      ast (~> 2.4.1)
+    powerpack (0.1.3)
+    pry (0.12.2)
+      coderay (~> 1.1.0)
+      method_source (~> 0.9.0)
+    rainbow (3.0.0)
     rake (12.3.3)
     rspec (3.10.0)
       rspec-core (~> 3.10.0)
@@ -21,13 +34,32 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.10.0)
     rspec-support (3.10.2)
+    rubocop (0.54.0)
+      parallel (~> 1.10)
+      parser (>= 2.5)
+      powerpack (~> 0.1)
+      rainbow (>= 2.2.2, < 4.0)
+      ruby-progressbar (~> 1.7)
+      unicode-display_width (~> 1.0, >= 1.0.1)
+    ruby-progressbar (1.11.0)
+    simplecov (0.21.2)
+      docile (~> 1.1)
+      simplecov-html (~> 0.11)
+      simplecov_json_formatter (~> 0.1)
+    simplecov-html (0.12.3)
+    simplecov_json_formatter (0.1.2)
+    unicode-display_width (1.7.0)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
+  byebug
+  pry (~> 0.12.2)
   rake (~> 12.0)
-  rspec (~> 3.0)
+  rspec (~> 3.6)
+  rubocop (= 0.54.0)
+  simplecov (~> 0.15)
   unitsml!
 
 BUNDLED WITH
diff --git a/lib/unitsml.rb b/lib/unitsml.rb
index fa246a7..2707500 100644
--- a/lib/unitsml.rb
+++ b/lib/unitsml.rb
@@ -1,8 +1,19 @@
 require "unitsml/version"
+require "unitsml/dimension"
+require "unitsml/quantity"
 require "unitsml/unit"
+require "unitsml/unit_system"
 
 module Unitsml
   def find_unit(ascii:)
     Unitsml::Unit.find_unit(ascii: ascii)
   end
+
+  def find_dimension(ascii:)
+    Unitsml::Dimension.find_unit(ascii: ascii)
+  end
+
+  def find_unit_system(ascii:)
+    Unitsml::UnitSystem.find_unit_system(ascii: ascii)
+  end
 end
diff --git a/lib/unitsml/dimension.rb b/lib/unitsml/dimension.rb
new file mode 100644
index 0000000..1d9355b
--- /dev/null
+++ b/lib/unitsml/dimension.rb
@@ -0,0 +1,86 @@
+module Unitsml
+  class Dimension
+    UNITS_DB_DIMENSIONS_PATH = File
+                      .expand_path("../../vendor/unitsdb/dimensions.yaml",
+                        File.dirname(__FILE__))
+                      .freeze
+
+    attr_reader :id,
+      :length,
+      :mass,
+      :time,
+      :electric_current,
+      :thermodynamic_temperature,
+      :amount_of_substance,
+      :luminous_intensity,
+      :plane_angle,
+      :dimensionless
+
+    class << self
+      def find_dimension(ascii:)
+        symbols.find { |unit| unit.id == ascii.to_s }
+      end
+
+      def symbols
+        @symbols ||= YAML
+                      .load(File.read(UNITS_DB_DIMENSIONS_PATH))
+                      .map { |(id, attrs)| Unitsml::Dimension.new(id, attrs) }
+      end
+
+      def from_yaml(yaml_path)
+        @symbols = YAML
+                    .load(File.read(yaml_path))
+                    .map { |(id, attrs)| Unitsml::Dimension.new(id, attrs) }
+      end
+    end
+
+    def initialize(id, hash)
+      begin
+        @id = id
+        @dimensionless = hash["dimensionless"]
+        hash["length"] and @length = hash["length"]["powerNumerator"].to_i
+        hash["mass"] and @mass = hash["mass"]["powerNumerator"].to_i
+        hash["time"] and @time = hash["time"]["powerNumerator"].to_i
+        hash["electric_current"] and @electric_current = hash["electric_current"]["powerNumerator"].to_i
+        hash["thermodynamic_temperature"] and
+          @thermodynamic_temperature = hash["thermodynamic_temperature"]["powerNumerator"].to_i
+        hash["amount_of_substance"] and @amount_of_substance = hash["amount_of_substance"]["powerNumerator"].to_i
+        hash["luminous_intensity"] and @luminous_intensity = hash["luminous_intensity"]["powerNumerator"].to_i
+        hash["plane_angle"] and @plane_angle = hash["plane_angle"]["powerNumerator"].to_i
+      rescue
+        raise StandardError.new "Parse fail on Dimension #{id}: #{hash}"
+      end
+    end
+
+    def keys
+      ret = []
+      @length and ret << "Length"
+      @mass and ret << "Mass"
+      @time and ret << "Time"
+      @electric_current and ret << "ElectricCurrent"
+      @thermodynamic_temperature and ret << "ThermodynamicTemperature"
+      @amount_of_substance and ret << "AmountOfSubstance"
+      @luminous_intensity and ret << "LuminousIntensity"
+      @plane_angle and ret << "PlaneAngle"
+      ret
+    end
+
+    def exponent(key)
+      case key
+      when "Length" then @length
+      when "Mass" then @mass
+      when "Time" then @time
+      when "ElectricCurrent" then @electric_current
+      when "ThermodynamicTemperature" then @thermodynamic_temperature
+      when "AmountOfSubstance" then @amount_of_substance
+      when "LuminousIntensity" then @luminous_intensity
+      when "PlaneAngle" then @plane_angle
+      end
+    end
+
+    def vector
+      "#{@length}:#{@mass}:#{@time}:#{@electric_current}:#{@thermodynamic_temperature}:#{@amount_of_substance}:"\
+        "#{@luminous_intensity}:#{@plane_angle}"
+    end
+  end
+end
diff --git a/lib/unitsml/quantity.rb b/lib/unitsml/quantity.rb
new file mode 100644
index 0000000..4135853
--- /dev/null
+++ b/lib/unitsml/quantity.rb
@@ -0,0 +1,60 @@
+require "unitsml/unit"
+
+module Unitsml
+  class Quantity
+    UNITS_DB_QUANTITIES_PATH = File
+                      .expand_path("../../vendor/unitsdb/quantities.yaml",
+                        File.dirname(__FILE__))
+                      .freeze
+
+    attr_reader :id, :dimension, :type, :names, :units
+
+    class << self
+      def find_quantity(ascii:)
+        symbols.find { |unit| unit.id == ascii.to_s }
+      end
+
+      def symbols
+        @symbols ||= YAML
+                      .load(File.read(UNITS_DB_QUANTITIES_PATH))
+                      .map { |(id, attrs)| Unitsml::Quantity.new(id, attrs) }
+      end
+
+      def from_yaml(yaml_path)
+        @symbols = YAML
+                    .load(File.read(yaml_path))
+                    .map { |(id, attrs)| Unitsml::Quantity.new(id, attrs) }
+      end
+    end
+
+    def initialize(id, hash)
+      begin
+        @id = id
+        @dimension = hash["dimension_url"].sub(/^#/, "")
+        @type = hash["quantity_type"]
+        hash["quantity_name"] and @names = hash["quantity_name"]
+        @units = serialize_units(hash["unit_reference"])
+      # rescue
+      #   raise StandardError.new "Parse fail on Quantity #{id}: #{hash}"
+      end
+    end
+
+    def serialize_units(unit_references)
+      return unless unit_references
+
+      unit_references
+        .map do |attrs|
+          id = attrs["url"].sub(/^#/, "")
+          Unitsml::Unit.symbols.find { |unit| unit.id == id }
+        end
+    end
+
+    def name
+      @names&.first
+    end
+
+    def unit
+      @units&.first
+    end
+  end
+end
\ No newline at end of file
diff --git a/lib/unitsml/unit.rb b/lib/unitsml/unit.rb
index 8b96a6b..22795db 100644
--- a/lib/unitsml/unit.rb
+++ b/lib/unitsml/unit.rb
@@ -1,8 +1,9 @@
 require "yaml"
+require "unitsml/unit_symbol"
 
 module Unitsml
   class Unit
-    UNITS_DB_PATH = File
+    UNITS_DB_UNITS_PATH = File
                       .expand_path("../../vendor/unitsdb/units.yaml",
                         File.dirname(__FILE__))
                       .freeze
@@ -21,32 +22,42 @@ class Unit
       :prefixed
 
     class << self
-      def find_unit(ascii: ascii)
-        id, attrs = symbols.find { |(id, attribute)| id == ascii.to_s }
-        Unitsml::Unit.new(id, attrs) if id
+      def find_unit(ascii:)
+        symbols.find { |unit| unit.symbols_hash.keys.include?(ascii.to_s) }
       end
 
       def symbols
-        @symbols ||= YAML.load(File.read(UNITS_DB_PATH))
+        @symbols ||= YAML
+                      .load(File.read(UNITS_DB_UNITS_PATH))
+                      .map { |(id, attrs)| Unitsml::Unit.new(id, attrs) }
+      end
+
+      def from_yaml(yaml_path)
+        @symbols = YAML
+                    .load(File.read(yaml_path))
+                    .map { |(id, attrs)| Unitsml::Unit.new(id, attrs) }
       end
     end
 
-    def initialize(id, hash)
+    def initialize(id, attrs)
       begin
         @id = id
         @short = short
-        @dimension = hash["dimension_url"].sub(/^#/, "")
-        hash["short"] && !hash["short"].empty? and @short = hash["short"]
-        @unit_system = hash["unit_system"]
-        @names = hash["unit_name"]
-        @symbols_hash = hash["unit_symbols"]&.each_with_object({}) { |h, m| m[h["id"]] = h } || {}
-        @symbols = hash["unit_symbols"]
-        hash["root_units"] and hash["root_units"]["enumerated_root_units"] and
-          @root = hash["root_units"]["enumerated_root_units"]
-        hash["quantity_reference"] and @quantities = hash["quantity_reference"].map { |x| x["url"].sub(/^#/, "") }
-        hash["si_derived_bases"] and @si_derived_bases = hash["si_derived_bases"]
+        @dimension = attrs["dimension_url"].sub(/^#/, "")
+        attrs["short"] && !attrs["short"].empty? and @short = attrs["short"]
+        @unit_system = attrs["unit_system"]
+        @names = attrs["unit_name"]
+        @symbols_hash = attrs["unit_symbols"]
+                          &.each_with_object({}) do |sym_attrs, res|
+                            res[sym_attrs["id"]] = Unitsml::UnitSymbol.new(id, sym_attrs)
+                          end || {}
+        @symbols = attrs["unit_symbols"]&.map { |sym_attrs| Unitsml::UnitSymbol.new(sym_attrs["id"], sym_attrs) }
+        attrs["root_units"] and attrs["root_units"]["enumerated_root_units"] and
+          @root = attrs["root_units"]["enumerated_root_units"]
+        attrs["quantity_reference"] and @quantities = attrs["quantity_reference"].map { |x| x["url"].sub(/^#/, "") }
+        attrs["si_derived_bases"] and @si_derived_bases = attrs["si_derived_bases"]
       rescue
-        raise StandardError.new "Parse fail on Unit #{id}: #{hash}"
+        raise StandardError.new "Parse fail on Unit #{id}: #{attrs}"
       end
     end
 
@@ -69,5 +80,9 @@ def symbolid
     def symbolids
       @symbols ? @symbols.map { |s| s["id"] } : [ @short ]
     end
+
+    def to_latex
+      @symbols.map(&:latex).reduce(:+) if @symbols
+    end
   end
 end
diff --git a/lib/unitsml/unit_symbol.rb b/lib/unitsml/unit_symbol.rb
new file mode 100644
index 0000000..27b9fdf
--- /dev/null
+++ b/lib/unitsml/unit_symbol.rb
@@ -0,0 +1,21 @@
+require "yaml"
+
+module Unitsml
+  class UnitSymbol
+    attr_reader :id,
+      :ascii,
+      :html,
+      :mathml,
+      :latex,
+      :unicode
+
+    def initialize(id, hash)
+      @id = hash['id']
+      @ascii = hash['ascii']
+      @html = hash['html']
+      @mathml = hash['mathml']
+      @latex = hash['latex']
+      @unicode = hash['unicode']
+    end
+  end
+end
diff --git a/lib/unitsml/unit_system.rb b/lib/unitsml/unit_system.rb
new file mode 100644
index 0000000..040a28a
--- /dev/null
+++ b/lib/unitsml/unit_system.rb
@@ -0,0 +1,36 @@
+module Unitsml
+  class UnitSystem
+    UNITS_DB_UNIT_SYSTEMS_PATH = File
+                      .expand_path("../../vendor/unitsdb/unit_systems.yaml",
+                        File.dirname(__FILE__))
+                      .freeze
+
+    attr_reader :id,
+      :name,
+      :acceptable
+
+    class << self
+      def find_unit_system(ascii:)
+        symbols.find { |unit| unit.id == ascii.to_s }
+      end
+
+      def symbols
+        @symbols ||= YAML
+                      .load(File.read(UNITS_DB_UNIT_SYSTEMS_PATH))
+                      .map { |attrs| Unitsml::UnitSystem.new(attrs["id"], attrs) }
+      end
+
+      def from_yaml(yaml_path)
+        @symbols = YAML
+                    .load(File.read(yaml_path))
+                    .map { |attrs| Unitsml::UnitSystem.new(attrs["id"], attrs) }
+      end
+    end
+
+    def initialize(id, attrs)
+      @id = attrs["id"]
+      @name = attrs["name"]
+      @acceptable = attrs["acceptable"]
+    end
+  end
+end
diff --git a/spec/fixtures/dimensions_test.yaml b/spec/fixtures/dimensions_test.yaml
new file mode 100644
index 0000000..00b1d43
--- /dev/null
+++ b/spec/fixtures/dimensions_test.yaml
@@ -0,0 +1,15 @@
+---
+NISTd1:
+  length:
+    powerNumerator: 1
+    symbol: L
+
+NISTd2:
+  mass:
+    powerNumerator: 1
+    symbol: M
+
+NISTd3:
+  time:
+    powerNumerator: 1
+    symbol: T
diff --git a/spec/fixtures/unit_systems_test.yaml b/spec/fixtures/unit_systems_test.yaml
new file mode 100644
index 0000000..01a4988
--- /dev/null
+++ b/spec/fixtures/unit_systems_test.yaml
@@ -0,0 +1,7 @@
+---
+- id: test1
+  name: SI
+  acceptable: true
+- id: test2
+  name: SI
+  acceptable: true
\ No newline at end of file
diff --git a/spec/fixtures/units_test.yaml b/spec/fixtures/units_test.yaml
new file mode 100644
index 0000000..20e0b1b
--- /dev/null
+++ b/spec/fixtures/units_test.yaml
@@ -0,0 +1,76 @@
+---
+"test1":
+  dimension_url: "#NISTd1"
+  short: meter
+  root: true
+  unit_system:
+    type: "SI_base"
+    name: "SI"
+  unit_name:
+    - "meter"
+  unit_symbols:
+    - id: "m"
+      ascii: "m"
+      html: "m"
+      mathml: "<mi mathvariant='normal'>m</mi>"
+      latex: \ensuremath{\mathrm{m}}
+      unicode: "m"
+  root_units:
+    enumerated_root_units:
+      - unit: "meter"
+        power_denominator: 1
+        power_numerator: 1
+  quantity_reference:
+    - name: "length"
+      url: "#NISTq1"
+    - name: "diameter"
+      url: "#NISTq100"
+    - name: "length of path"
+      url: "#NISTq101"
+    - name: "cartesian coordinates"
+      url: "#NISTq102"
+    - name: "position vector"
+      url: "#NISTq103"
+    - name: "displacement"
+      url: "#NISTq104"
+    - name: "radius of curvature"
+      url: "#NISTq105"
+    - name: "wavelength"
+      url: "#NISTq114"
+    - name: "distance"
+      url: "#NISTq48"
+    - name: "breadth"
+      url: "#NISTq95"
+    - name: "height"
+      url: "#NISTq96"
+    - name: "thickness"
+      url: "#NISTq97"
+    - name: "radius"
+      url: "#NISTq98"
+    - name: "radial distance"
+      url: "#NISTq99"
+
+"test2":
+  dimension_url: "#NISTd7"
+  short: candela
+  root: true
+  unit_system:
+    type: "SI_base"
+    name: "SI"
+  unit_name:
+    - "candela"
+  unit_symbols:
+    - id: "cd"
+      ascii: "cd"
+      html: "cd"
+      mathml: "<mi mathvariant='normal'>cd</mi>"
+      latex: \ensuremath{\mathrm{cd}}
+      unicode: "cd"
+  root_units:
+    enumerated_root_units:
+      - unit: "candela"
+        power_denominator: 1
+        power_numerator: 1
+  quantity_reference:
+    - name: "luminous intensity"
+      url: "#NISTq7"
\ No newline at end of file
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 1ed808f..49f45bb 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,5 +1,6 @@
 require "bundler/setup"
 require "unitsml"
+require "byebug"
 
 RSpec.configure do |config|
   # Enable flags like --only-failures and --next-failure
@@ -12,3 +13,7 @@
     c.syntax = :expect
   end
 end
+
+def fixtures_path(path)
+  File.join(File.expand_path("./fixtures", __dir__), path)
+end
\ No newline at end of file
diff --git a/spec/unitsml/dimension_spec.rb b/spec/unitsml/dimension_spec.rb
new file mode 100644
index 0000000..62f86ee
--- /dev/null
+++ b/spec/unitsml/dimension_spec.rb
@@ -0,0 +1,35 @@
+require "spec_helper"
+
+RSpec.describe Unitsml::Dimension do
+  describe ".find_dimension" do
+    subject(:find_dimension) { described_class.find_dimension(ascii: dimension_symbol) }
+
+    context 'when existing symbol' do
+      let(:dimension_symbol) { :NISTd1 }
+
+      it 'returns instance of Unitsml::Dimension' do
+        expect(find_dimension).to(be_instance_of(Unitsml::Dimension))
+        expect(find_dimension.id).to(eq("NISTd1"))
+      end
+    end
+
+    context 'when non existing symbol' do
+      let(:dimension_symbol) { :random_name }
+
+      it 'returns nil' do
+        expect(find_dimension).to(be_nil)
+      end
+    end
+  end
+
+  describe ".from_yaml" do
+    subject(:from_yaml) { described_class.from_yaml(yaml_path) }
+
+    let(:yaml_path) { fixtures_path('dimensions_test.yaml') }
+
+    it "loads symbols files and uses it for lookup" do
+      expect { from_yaml }.to change { described_class.symbols.length }.to(3)
+      expect(described_class.symbols.map(&:id)).to(eq(%w[NISTd1 NISTd2 NISTd3]))
+    end
+  end
+end
\ No newline at end of file
diff --git a/spec/unitsml/quantity_spec.rb b/spec/unitsml/quantity_spec.rb
new file mode 100644
index 0000000..ac31672
--- /dev/null
+++ b/spec/unitsml/quantity_spec.rb
@@ -0,0 +1,36 @@
+require "spec_helper"
+
+RSpec.describe Unitsml::Quantity do
+  describe ".find_quantity" do
+    subject(:find_quantity) { described_class.find_quantity(ascii: unit_symbol) }
+
+    context 'when existing symbol' do
+      let(:unit_symbol) { "NISTq48" }
+
+      it 'returns instance of Unitsml::Unit' do
+        expect(find_quantity).to(be_instance_of(described_class))
+        expect(find_quantity.id).to(eq(unit_symbol))
+        expect(find_quantity.units.first).to(be_instance_of(Unitsml::Unit))
+      end
+    end
+
+    context 'when non existing symbol' do
+      let(:unit_symbol) { :random_name }
+
+      it 'returns nil' do
+        expect(find_quantity).to(be_nil)
+      end
+    end
+  end
+
+  describe ".from_yaml" do
+    subject(:from_yaml) { described_class.from_yaml(yaml_path) }
+
+    let(:yaml_path) { fixtures_path('units_test.yaml') }
+
+    it "loads symbols files and uses it for lookup" do
+      expect { from_yaml }.to change { described_class.symbols.length }.to(2)
+      expect(described_class.symbols.map(&:id)).to(eq(%w[test1 test2]))
+    end
+  end
+end
\ No newline at end of file
diff --git a/spec/unitsml/unit_spec.rb b/spec/unitsml/unit_spec.rb
index 59df5cc..ba17c0d 100644
--- a/spec/unitsml/unit_spec.rb
+++ b/spec/unitsml/unit_spec.rb
@@ -5,11 +5,13 @@
     subject(:find_unit) { described_class.find_unit(ascii: unit_symbol) }
 
     context 'when existing symbol' do
-      let(:unit_symbol) { :NISTu1 }
+      let(:unit_symbol) { "mL" }
 
       it 'returns instance of Unitsml::Unit' do
         expect(find_unit).to(be_instance_of(Unitsml::Unit))
-        expect(find_unit.short).to(eq("meter"))
+        expect(find_unit.short).to(eq("milliliter"))
+        expect(find_unit.symbols.first).to(be_instance_of(Unitsml::UnitSymbol))
+        expect(find_unit.to_latex).to(eq("\\ensuremath{\\mathrm{mL}}\\ensuremath{\\mathrm{ml}}"))
       end
     end
 
@@ -21,4 +23,15 @@
       end
     end
   end
+
+  describe ".from_yaml" do
+    subject(:from_yaml) { described_class.from_yaml(yaml_path) }
+
+    let(:yaml_path) { fixtures_path('units_test.yaml') }
+
+    it "loads symbols files and uses it for lookup" do
+      expect { from_yaml }.to change { described_class.symbols.length }.to(2)
+      expect(described_class.symbols.map(&:id)).to(eq(%w[test1 test2]))
+    end
+  end
 end
\ No newline at end of file
diff --git a/spec/unitsml/unit_system_spec.rb b/spec/unitsml/unit_system_spec.rb
new file mode 100644
index 0000000..437b668
--- /dev/null
+++ b/spec/unitsml/unit_system_spec.rb
@@ -0,0 +1,35 @@
+require "spec_helper"
+
+RSpec.describe Unitsml::UnitSystem do
+  describe ".find_unit_system_system" do
+    subject(:find_unit_system) { described_class.find_unit_system(ascii: unit_symbol) }
+
+    context 'when existing symbol' do
+      let(:unit_symbol) { "SI_base" }
+
+      it 'returns instance of Unitsml::UnitSystem' do
+        expect(find_unit_system).to(be_instance_of(described_class))
+        expect(find_unit_system.name).to(eq("SI"))
+      end
+    end
+
+    context 'when non existing symbol' do
+      let(:unit_symbol) { :random_name }
+
+      it 'returns nil' do
+        expect(find_unit_system).to(be_nil)
+      end
+    end
+  end
+
+  describe ".from_yaml" do
+    subject(:from_yaml) { described_class.from_yaml(yaml_path) }
+
+    let(:yaml_path) { fixtures_path("unit_systems_test.yaml") }
+
+    it "loads symbols files and uses it for lookup" do
+      expect { from_yaml }.to change { described_class.symbols.length }.to(2)
+      expect(described_class.symbols.map(&:id)).to(eq(%w[test1 test2]))
+    end
+  end
+end
\ No newline at end of file
diff --git a/spec/unitsml_spec.rb b/spec/unitsml_spec.rb
index ff927b3..77fb592 100644
--- a/spec/unitsml_spec.rb
+++ b/spec/unitsml_spec.rb
@@ -2,8 +2,4 @@
   it "has a version number" do
     expect(Unitsml::VERSION).not_to be nil
   end
-
-  it "does something useful" do
-    expect(false).to eq(true)
-  end
 end
diff --git a/unitsml.gemspec b/unitsml.gemspec
index e5e026e..6bb602f 100644
--- a/unitsml.gemspec
+++ b/unitsml.gemspec
@@ -24,4 +24,11 @@ Gem::Specification.new do |spec|
   spec.bindir        = "exe"
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
+
+  spec.add_development_dependency "byebug"
+  spec.add_development_dependency "pry", "~> 0.12.2"
+  spec.add_development_dependency "rake", "~> 12.0"
+  spec.add_development_dependency "rspec", "~> 3.6"
+  spec.add_development_dependency "rubocop", "= 0.54.0"
+  spec.add_development_dependency "simplecov", "~> 0.15"
 end