Merge pull request #4 from matic-insurance/feature/configuration_inte…

…rface

Singleton Interface

.travis.yml

@@ -11,5 +11,4 @@ deploy:
   provider: rubygems
   api_key: "$RUBY_GEMS_API_KEY"
   on:
-    branch: master
     tags: true

README.md

@@ -54,10 +54,12 @@ gem 'id_generator'
 ```ruby
 # Somewhere during project start
 context_id = 165 # value from 0 to 255
-ID_GENERATOR = IdGenerator.new(context_id)
+IdGenerator.configuration.context_id = context_id
+# Or using block
+IdGenerator.configure {|config| config.context_id = context_id} 
 
 #Inside of the actual code
-ID_GENERATOR.generate
+IdGenerator.generate
 ```
 
 ## Contributing

lib/id_generator.rb

@@ -1,46 +1,22 @@
-require 'securerandom'
-
-class IdGenerator
-  VERSION = '0.1.2'.freeze
-
-  COUNTER_PART_SIZE = 8
-  CONTEXT_PART_SIZE = 2
-
-  RANDOM_PART_BYTES = 11
-  COUNTER_START = Time.new(2000).to_i
-
-  class Error < StandardError
-  end
-
-  def initialize(context_id)
-    raise(IdGenerator::Error, 'Invalid project id') unless context_id_valid?(context_id)
-
-    @context_id = value_to_hex(context_id, CONTEXT_PART_SIZE)
-  end
-
-  def generate
-    "#{time}-#{@context_id}-#{random_number}"
-  end
-
-  private
-
-  def context_id_valid?(context_id)
-    return false unless context_id.is_a?(Integer)
-    return false unless context_id.between?(0, 255)
-
-    true
+require 'id_generator/version'
+require 'id_generator/configuration'
+require 'id_generator/errors'
+require 'id_generator/generators/timestamped_random'
+
+module IdGenerator
+  def self.configure
+    yield(configuration)
   end
 
-  def time
-    timestamp = Time.now.to_i - COUNTER_START
-    value_to_hex(timestamp, COUNTER_PART_SIZE)
+  def self.generate
+    id_generator.generate
   end
 
-  def random_number
-    SecureRandom.hex(RANDOM_PART_BYTES)
+  def self.configuration
+    @configuration ||= Configuration.new
   end
 
-  def value_to_hex(value, size)
-    format("%0#{size}x", value)
+  def self.id_generator
+    @id_generator ||= IdGenerator::Generators::TimestampedRandom.new(configuration)
   end
 end

lib/id_generator/configuration.rb

@@ -0,0 +1,24 @@
+module IdGenerator
+  class Configuration
+    attr_reader :context_id
+
+    def initialize(context_id: 0)
+      self.context_id = context_id
+    end
+
+    def context_id=(context_id)
+      raise(IdGenerator::Errors::InvalidContextId, 'Invalid context id') unless context_id_valid?(context_id)
+
+      @context_id = context_id
+    end
+
+    protected
+
+    def context_id_valid?(context_id)
+      return false unless context_id.is_a?(Integer)
+      return false unless context_id.between?(0, 255)
+
+      true
+    end
+  end
+end

lib/id_generator/errors.rb

@@ -0,0 +1,7 @@
+module IdGenerator
+  module Errors
+    class InvalidContextId < StandardError
+      # Just empty line to trick codacy
+    end
+  end
+end

lib/id_generator/generators/timestamped_random.rb

@@ -0,0 +1,42 @@
+require 'securerandom'
+
+module IdGenerator
+  module Generators
+    class TimestampedRandom
+      COUNTER_PART_SIZE = 8
+      CONTEXT_PART_SIZE = 2
+
+      RANDOM_PART_BYTES = 11
+      COUNTER_START = Time.new(2000).to_i
+
+      attr_reader :config
+
+      def initialize(config)
+        @config = config
+      end
+
+      def generate
+        "#{time}-#{context_id}-#{random_number}"
+      end
+
+      private
+
+      def time
+        timestamp = Time.now.to_i - COUNTER_START
+        value_to_hex(timestamp, COUNTER_PART_SIZE)
+      end
+
+      def context_id
+        value_to_hex(config.context_id, CONTEXT_PART_SIZE)
+      end
+
+      def random_number
+        SecureRandom.hex(RANDOM_PART_BYTES)
+      end
+
+      def value_to_hex(value, size)
+        format("%0#{size}x", value)
+      end
+    end
+  end
+end

lib/id_generator/version.rb

@@ -0,0 +1,3 @@
+module IdGenerator
+  VERSION = '0.1.2'.freeze
+end

spec/lib/id_generator/configuration_spec.rb

@@ -0,0 +1,44 @@
+require 'spec_helper'
+
+RSpec.describe IdGenerator::Configuration do
+  describe '#context_id' do
+    let(:configuration) { described_class.new(context_id: context_id) }
+    let(:context_id) { rand(255) }
+
+    it 'returns initialized value' do
+      expect(configuration.context_id).to eq(context_id)
+    end
+
+    describe 'validation' do
+      let(:error) { IdGenerator::Errors::InvalidContextId }
+
+      it 'allows empty' do
+        expect { described_class.new }.not_to raise_error
+      end
+
+      it 'allows 0' do
+        expect { described_class.new(context_id: 0) }.not_to raise_error
+      end
+
+      it 'allows 255' do
+        expect { described_class.new(context_id: 255) }.not_to raise_error
+      end
+
+      it 'rejects negative values' do
+        expect { described_class.new(context_id: -1) }.to raise_error(error, 'Invalid context id')
+      end
+
+      it 'rejects large values' do
+        expect { described_class.new(context_id: rand(256..1000)) }.to raise_error(error, 'Invalid context id')
+      end
+
+      it 'rejects empty values' do
+        expect { described_class.new(context_id: nil) }.to raise_error(error, 'Invalid context id')
+      end
+
+      it 'rejects invalid values' do
+        expect { described_class.new(context_id: 'id') }.to raise_error(error, 'Invalid context id')
+      end
+    end
+  end
+end

spec/lib/id_generator/generators/timestamped_random_spec.rb

@@ -0,0 +1,55 @@
+RSpec.describe IdGenerator::Generators::TimestampedRandom do
+  let(:generator) { described_class.new(configuration) }
+  let(:context_id) { rand(255) }
+  let(:configuration) { IdGenerator::Configuration.new(context_id: context_id) }
+
+  describe 'id format' do
+    let(:parts) { uniq_id.split('-') }
+
+    it 'has correct size' do
+      expect(uniq_id.size).to eq(34)
+    end
+
+    it 'has correct format' do
+      expect(uniq_id).to match(/^[a-z0-9\-]+$/)
+    end
+
+    it 'has 2 separators' do
+      expect(parts.size).to eq(3)
+    end
+
+    it 'has correct timestamp size' do
+      expect(parts[0].size).to eq(8)
+    end
+
+    it 'has correct project id size' do
+      expect(parts[1].size).to eq(2)
+    end
+
+    it 'has correct random part size' do
+      expect(parts[2].size).to eq(22)
+    end
+
+    it 'includes timestamp' do
+      timestamp = Time.now.to_i - Time.new(2000).to_i
+      id_timestamp = uniq_id.split('-').first.to_i(16)
+      expect(id_timestamp).to be_between(timestamp, timestamp + 2)
+    end
+
+    it 'include project id' do
+      expect(uniq_id).to include(format('-%02x-', context_id))
+    end
+  end
+
+  describe '#generate' do
+    it 'generates random id every time' do
+      expect(uniq_id).not_to eq(uniq_id)
+    end
+  end
+
+  protected
+
+  def uniq_id
+    generator.generate
+  end
+end

spec/lib/id_generator_spec.rb

@@ -1,80 +1,43 @@
 RSpec.describe IdGenerator do
-  let(:generator) { described_class.new(context_id) }
-  let(:context_id) { rand(255) }
+  let(:context_error) { IdGenerator::Errors::InvalidContextId }
 
-  describe 'id format' do
-    let(:parts) { uniq_id.split('-') }
+  after { described_class.configuration.context_id = 0 }
 
-    it 'has correct size' do
-      expect(uniq_id.size).to eq(34)
-    end
-
-    it 'has correct format' do
-      expect(uniq_id).to match(/^[a-z0-9\-]+$/)
-    end
-
-    it 'has 2 separators' do
-      expect(parts.size).to eq(3)
-    end
-
-    it 'has correct timestamp size' do
-      expect(parts[0].size).to eq(8)
-    end
-
-    it 'has correct project id size' do
-      expect(parts[1].size).to eq(2)
-    end
-
-    it 'has correct random part size' do
-      expect(parts[2].size).to eq(22)
-    end
-
-    it 'includes timestamp' do
-      timestamp = Time.now.to_i - Time.new(2000).to_i
-      id_timestamp = uniq_id.split('-').first.to_i(16)
-      expect(id_timestamp).to be_between(timestamp, timestamp + 2)
+  describe '#generate' do
+    it 'generates random id every time' do
+      expect(uniq_id).not_to eq(uniq_id)
     end
 
-    it 'include project id' do
-      expect(uniq_id).to include(format('-%02x-', context_id))
+    it 'using default context id' do
+      expect(uniq_id).to include('-00-')
     end
   end
 
-  describe 'context_id' do
-    it 'allows 0' do
-      expect { described_class.new(0) }.not_to raise_error
-    end
-
-    it 'allows 255' do
-      expect { described_class.new(255) }.not_to raise_error
+  describe '#configure' do
+    it 'setting context id' do
+      described_class.configure { |c| c.context_id = 15 }
+      expect(uniq_id).to include('-0f-')
     end
 
-    it 'rejects negative values' do
-      expect { described_class.new(-1) }.to raise_error(IdGenerator::Error, 'Invalid project id')
-    end
-
-    it 'rejects large values' do
-      expect { described_class.new(rand(256..1000)) }.to raise_error(IdGenerator::Error, 'Invalid project id')
-    end
-
-    it 'rejects empty values' do
-      expect { described_class.new(nil) }.to raise_error(IdGenerator::Error, 'Invalid project id')
+    it 'validating context id' do
+      expect { described_class.configure { |c| c.context_id = -1 } }.to raise_error(context_error)
     end
+  end
 
-    it 'rejects invalid values' do
-      expect { described_class.new('id') }.to raise_error(IdGenerator::Error, 'Invalid project id')
+  describe '#configuration' do
+    it 'setting context id' do
+      described_class.configuration.context_id = 15
+      expect(uniq_id).to include('-0f-')
     end
-  end
 
-  describe '#generate' do
-    it 'generates random id every time' do
-      expect(uniq_id).not_to eq(uniq_id)
+    it 'validating context id' do
+      expect { described_class.configuration.context_id = -1 }.to raise_error(context_error)
     end
   end
 
   protected
 
   def uniq_id
-    generator.generate
+    described_class.generate
   end
 end