Add support for different configurations

.gitignore

@@ -1,2 +1,3 @@
 *.gem
 .DS_Store
+.idea

lib/global_call.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+module Rk
+  # Anonymous module for including +rk+ to global namespace (class Object).
+  class GlobalCall < Module
+    def initialize(rk_instance)
+      rk_name = if rk_instance.rk_name.to_s.empty?
+        "rk"
+      else
+        "#{rk_instance.rk_name}_rk"
+      end
+
+      $_rk ||= {}
+      $_rk[rk_name] = rk_instance
+
+      super() do
+        define_method rk_name do |*elements|
+          if elements.empty?
+            $_rk[rk_name]
+          else
+            $_rk[rk_name].rk(elements)
+          end
+        end
+      end
+    end
+  end
+end

lib/rk.rb

@@ -1,20 +1,35 @@
-# Module for including +rk+ to global namespace (class Object).
+# frozen_string_literal: true
+
+require_relative "../lib/global_call"
+
 module Rk
 
+  # Create a rk-configuration
+  #  * <tt>name</tt> - : optional for creating named configurations
+  #  * <tt>block</tt> - : optional for setting configurations for details see Rk#initialize
+  def self.configure(name = nil)
+    instance = Rk.new
+    instance.rk_name = name
+    yield(instance) if block_given?
+
+    Object.include(GlobalCall.new(instance))
+  end
+
   # Build Redis keys of several elements.
   #   rk("user", 10) => "user:10"
   class Rk
-    attr_accessor :separator, :prefix, :suffix, :keys
+    attr_accessor :separator, :prefix, :suffix, :keys, :rk_name
 
     # Set defaults
     # * <tt>separator</tt> - :
     # * <tt>prefix</tt> - empty
     # * <tt>suffix</tt> - empty
     # * <tt>keys</tt> - empty
     def initialize
-      @separator = ":"
-      @prefix = ""
-      @suffix = ""
+      self.separator = ":"
+      self.prefix = ""
+      self.suffix = ""
+      # attr_accessor is overwritten to create methods for keys
       @keys = {}
     end
 
@@ -28,7 +43,9 @@ def rk(*elements)
     #   rk(rk.user, 10) => "user:10"
     def method_missing(method, *arg)
       # Raise an error if a method gets accessed which was not defined before
-      raise RuntimeError, "'rk.#{method.to_s}' is undefined" unless method.to_s.include?("=")
+      unless method.to_s.include?("=")
+        return super
+      end
 
       # Define a method to return a value as set, for example rk.settings = 'set' defines
       # a method called "settings" which returns the string "set"
@@ -58,27 +75,10 @@ def keys=(h)
         self.send("#{key}=", val)
       end
     end
-
   end # class Rk
-
-  # Create and call a global instance of Rk to either build a key or set/get attributes.
-  def rk(*elements)
-    $_rk = Rk.new unless $_rk
-
-    # Differ between calling "rk" without/with params
-    if elements.empty?
-      # Return instance of Rk for calling methods like "rk.separator"
-      $_rk
-    else
-      # Return key build by Rk.rk
-      $_rk.rk(elements)
-    end
-  end
-
 end # module Rk
 
+# Create a default rk to use it without configuring anything
 # We could use +extend Rk+ to extend only +main+, but we would have to +include Rk+ in
-# any class, hence we include Rk to the global object.
-class Object
-  include Rk
-end
+# any class, hence we include Rk to the global object
+Object.include(Rk::GlobalCall.new(Rk::Rk.new))

rk.gemspec

@@ -1,12 +1,13 @@
 Gem::Specification.new do |g|
   g.name = "rk"
   g.version = "1.1.0"
-  g.date = "2016-12-21"
   g.summary = "Redis key builder"
   g.description = "Ruby helper to generate keys for Redis"
   g.authors = ["Oliver Mensinger"]
   g.email = "oliver.mensinger@gmail.com"
-  g.files = ["lib/rk.rb"]
+  g.files = %w[lib/global_call.rb lib/rk.rb]
   g.homepage = "https://github.com/omensinger/rk"
   g.license = "MIT"
+
+  g.add_development_dependency "minitest"
 end

test/test_rk.rb

@@ -18,9 +18,11 @@ def key
   let(:keys) { { user: "user", "statistics" => "stats", "session" => :sess } }
 
   def setup
-    rk.separator = ":"
-    rk.prefix = ""
-    rk.suffix = ""
+    Rk.configure do |config|
+      config.separator = ":"
+      config.prefix = ""
+      config.suffix = ""
+    end
   end
 
   def test_simple_key
@@ -60,7 +62,7 @@ def test_use_defined_key_element
   end
 
   def test_use_undefined_key_element
-    assert_raises RuntimeError do
+    assert_raises NoMethodError do
       rk.something
     end
   end
@@ -86,4 +88,33 @@ def test_get_keys
     assert_equal keys_as_strings, rk.keys
   end
 
+  def test_can_access_config_attributes
+    Rk.configure("test") do |config|
+      config.separator = ":"
+      config.prefix = "pre"
+      config.suffix = "suf"
+    end
+
+    assert_equal ":", test_rk.separator
+    assert_equal "pre", test_rk.prefix
+    assert_equal "suf", test_rk.suffix
+    assert_equal "test", test_rk.rk_name
+  end
+
+  def test_allow_second_setting
+    Rk.configure("foo") do |config|
+      config.separator = "-"
+    end
+
+    assert_equal "-", foo_rk.separator
+    assert_equal ":", rk.separator
+  end
+
+  def test_named_rk_creates_key
+    Rk.configure("foo") do |config|
+      config.prefix = "foo"
+      config.separator = "-"
+    end
+    assert_equal "foo-bar", foo_rk("bar")
+  end
 end