Be more conservative when overwriting core lib

This allows more conservation. It avoids developer being bombarded by
warnings when used inside another project. It also allows for previous
definitions of numeric if a person, inside a project, decides that it is
1_000 bytes in a Kb instead of the correct 1_024.

This is generally a better approach to straight up monkey-patching.

lib/core_ext/numeric_bytes.rb

@@ -25,68 +25,72 @@
 # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+begin
+  require 'active_support/core_ext/numeric/bytes'
+rescue LoadError
+  class Numeric
+    KILOBYTE = 1024 unless defined? KILOBYTE
+    MEGABYTE = KILOBYTE * 1024 unless defined? MEGABYTE
+    GIGABYTE = MEGABYTE * 1024 unless defined? GIGABYTE
+    TERABYTE = GIGABYTE * 1024 unless defined? TERABYTE
+    PETABYTE = TERABYTE * 1024 unless defined? PETABYTE
+    EXABYTE  = PETABYTE * 1024 unless defined? EXABYTE
 
-class Numeric
-  KILOBYTE = 1024
-  MEGABYTE = KILOBYTE * 1024
-  GIGABYTE = MEGABYTE * 1024
-  TERABYTE = GIGABYTE * 1024
-  PETABYTE = TERABYTE * 1024
-  EXABYTE  = PETABYTE * 1024
+    # Enables the use of byte calculations and declarations, like 45.bytes + 2.6.megabytes
+    #
+    #   2.bytes # => 2
+    def bytes
+      self
+    end unless method_defined? :bytes
+    alias :byte :bytes unless method_defined? :byte
 
-  # Enables the use of byte calculations and declarations, like 45.bytes + 2.6.megabytes
-  #
-  #   2.bytes # => 2
-  def bytes
-    self
-  end
-  alias :byte :bytes
-
-  # Returns the number of bytes equivalent to the kilobytes provided.
-  #
-  #   2.kilobytes # => 2048
-  def kilobytes
-    self * KILOBYTE
-  end
-  alias :kilobyte :kilobytes
+    # Returns the number of bytes equivalent to the kilobytes provided.
+    #
+    #   2.kilobytes # => 2048
+    def kilobytes
+      self * KILOBYTE
+    end unless method_defined? :kilobytes
+    alias :kilobyte :kilobytes unless method_defined? :kilobyte
 
-  # Returns the number of bytes equivalent to the megabytes provided.
-  #
-  #   2.megabytes # => 2_097_152
-  def megabytes
-    self * MEGABYTE
-  end
-  alias :megabyte :megabytes
+    # Returns the number of bytes equivalent to the megabytes provided.
+    #
+    #   2.megabytes # => 2_097_152
+    def megabytes
+      self * MEGABYTE
+    end unless method_defined? :megabytes?
+    alias :megabyte :megabytes unless method_defined? :megabyte
 
-  # Returns the number of bytes equivalent to the gigabytes provided.
-  #
-  #   2.gigabytes # => 2_147_483_648
-  def gigabytes
-    self * GIGABYTE
-  end
-  alias :gigabyte :gigabytes
+    # Returns the number of bytes equivalent to the gigabytes provided.
+    #
+    #   2.gigabytes # => 2_147_483_648
+    def gigabytes
+      self * GIGABYTE
+    end unless method_defined? :gigabytes
+    alias :gigabyte :gigabytes unless method_defined? :gigabyte
 
-  # Returns the number of bytes equivalent to the terabytes provided.
-  #
-  #   2.terabytes # => 2_199_023_255_552
-  def terabytes
-    self * TERABYTE
-  end
-  alias :terabyte :terabytes
+    # Returns the number of bytes equivalent to the terabytes provided.
+    #
+    #   2.terabytes # => 2_199_023_255_552
+    def terabytes
+      self * TERABYTE
+    end unless method_defined? :terabytes
+    alias :terabyte :terabytes unless method_defined? :terabyte
 
-  # Returns the number of bytes equivalent to the petabytes provided.
-  #
-  #   2.petabytes # => 2_251_799_813_685_248
-  def petabytes
-    self * PETABYTE
-  end
-  alias :petabyte :petabytes
+    # Returns the number of bytes equivalent to the petabytes provided.
+    #
+    #   2.petabytes # => 2_251_799_813_685_248
+    def petabytes
+      self * PETABYTE
+    end unless method_defined? :petabytes
+    alias :petabyte :petabytes unless method_defined? :petabyte
 
-  # Returns the number of bytes equivalent to the exabytes provided.
-  #
-  #   2.exabytes # => 2_305_843_009_213_693_952
-  def exabytes
-    self * EXABYTE
+    # Returns the number of bytes equivalent to the exabytes provided.
+    #
+    #   2.exabytes # => 2_305_843_009_213_693_952
+    def exabytes
+      self * EXABYTE
+    end unless method_defined? :exabytes
+    alias :exabyte :exabytes unless method_defined? :exabyte
   end
-  alias :exabyte :exabytes
 end
+