mime-types 2.6 release ready code.

- Extend documentation.
- Add a logger and logger configuration.
- Add more tests to Travis.
- Update MIME registry.

7 files changed, 349 insertions, 229 deletions

diff --git a/lib/mime/type.rb b/lib/mime/type.rb
index c49ffb9..29066a2 100644
--- a/lib/mime/type.rb
+++ b/lib/mime/type.rb
@@ -1,8 +1,5 @@
 # -*- ruby encoding: utf-8 -*-
 
-require 'mime/types/deprecations'
-require 'json'
-
 # The definition of one MIME content-type.
 #
 # == Usage
@@ -50,16 +47,17 @@ class MIME::Type
     end
 
     def to_s
-      "Invalid Encoding #{@encoding.inspect} (valid values: #{VALID_ENCODINGS.inspect})."
+      "Invalid Encoding #{@encoding.inspect}"
     end
     # :startdoc:
   end
 
   # The released version of the mime-types library.
-  VERSION = '2.5'
+  VERSION = '2.6'
 
   include Comparable
 
+  # :stopdoc:
   MEDIA_TYPE_RE     = %r{([-\w.+]+)/([-\w.+]*)}o
   UNREGISTERED_RE   = %r{[Xx]-}o
   I18N_RE           = %r{[^[:alnum:]]}o
@@ -70,20 +68,22 @@ class MIME::Type
   TEXT_ENCODINGS    = %w(7bit quoted-printable)
   VALID_ENCODINGS   = DEFAULT_ENCODINGS + BINARY_ENCODINGS + TEXT_ENCODINGS
 
-  IANA_URL          = "http://www.iana.org/assignments/media-types/%s/%s"
-  RFC_URL           = "http://rfc-editor.org/rfc/rfc%s.txt"
-  DRAFT_URL         = "http://datatracker.ietf.org/public/idindex.cgi?command=id_details&filename=%s"
-  CONTACT_URL       = "http://www.iana.org/assignments/contact-people.htm#%s"
+  IANA_URL          = 'http://www.iana.org/assignments/media-types/%s/%s'
+  RFC_URL           = 'http://rfc-editor.org/rfc/rfc%s.txt'
+  DRAFT_URL         = 'http://datatracker.ietf.org/public/idindex.cgi?command=id_details&filename=%s' # rubocop:disable Metrics/LineLength
+  CONTACT_URL       = 'http://www.iana.org/assignments/contact-people.htm#%s'
+  # :startdoc:
 
   if respond_to? :private_constant
     private_constant :MEDIA_TYPE_RE, :UNREGISTERED_RE, :I18N_RE, :PLATFORM_RE,
-      :DEFAULT_ENCODINGS, :BINARY_ENCODINGS, :TEXT_ENCODINGS, :VALID_ENCODINGS,
-      :IANA_URL, :RFC_URL, :DRAFT_URL, :CONTACT_URL
+                     :DEFAULT_ENCODINGS, :BINARY_ENCODINGS, :TEXT_ENCODINGS,
+                     :VALID_ENCODINGS, :IANA_URL, :RFC_URL, :DRAFT_URL,
+                     :CONTACT_URL
   end
 
-  # Builds a MIME::Type object from the provided MIME Content Type value
-  # (e.g., 'text/plain' or 'applicaton/x-eruby'). The constructed object is
-  # yielded to an optional block for additional configuration, such as
+  # Builds a MIME::Type object from the +content_type+, a MIME Content Type
+  # value (e.g., 'text/plain' or 'applicaton/x-eruby'). The constructed object
+  # is yielded to an optional block for additional configuration, such as
   # associating extensions and encoding information.
   #
   # * When provided a Hash or a MIME::Type, the MIME::Type will be
@@ -92,39 +92,41 @@ class MIME::Type
   #   the first two elements of the array as the content type and
   #   extensions.
   # * Otherwise, the content_type will be used as a string.
+  #
+  # Yields the newly constructed +self+ object.
   def initialize(content_type) # :yields self:
-    @friendly         = {}
-    self.system      = nil
-    self.obsolete    = false
-    self.registered  = nil
+    @friendly = {}
+    self.system = nil
+    self.obsolete = false
+    self.registered = nil
     self.use_instead = nil
-    self.signature   = nil
+    self.signature = nil
 
     case content_type
     when Hash
       init_with(content_type)
     when Array
       self.content_type = content_type[0]
-      self.extensions   = content_type[1] || []
+      self.extensions = content_type[1] || []
     when MIME::Type
       init_with(content_type.to_h)
     else
       self.content_type = content_type
     end
 
-    self.extensions   ||= []
-    self.docs         ||= nil
-    self.encoding     ||= :default
+    self.extensions ||= []
+    self.docs ||= []
+    self.encoding ||= :default
     # This value will be deprecated in the future, as it will be an
     # alternative view on #xrefs. Silence an unnecessary warning for now by
     # assigning directly to the instance variable.
-    @references       ||= []
-    self.xrefs        ||= {}
+    @references ||= []
+    self.xrefs ||= {}
 
     yield self if block_given?
   end
 
-  # Returns +true+ if the simplified type matches the current
+  # Returns +true+ if the +other+ simplified type matches the current type.
   def like?(other)
     if other.respond_to?(:simplified)
       @simplified == other.simplified
@@ -133,10 +135,10 @@ class MIME::Type
     end
   end
 
-  # Compares the MIME::Type against the exact content type or the simplified
-  # type (the simplified type will be used if comparing against something
-  # that can be treated as a String with #to_s). In comparisons, this is
-  # done against the lowercase version of the MIME::Type.
+  # Compares the +other+ MIME::Type against the exact content type or the
+  # simplified type (the simplified type will be used if comparing against
+  # something that can be treated as a String with #to_s). In comparisons, this
+  # is done against the lowercase version of the MIME::Type.
   def <=>(other)
     if other.respond_to?(:content_type)
       @content_type.downcase <=> other.content_type.downcase
@@ -145,7 +147,7 @@ class MIME::Type
     end
   end
 
-  # Compares the MIME::Type based on how reliable it is before doing a
+  # Compares the +other+ MIME::Type based on how reliable it is before doing a
   # normal <=> comparison. Used by MIME::Types#[] to sort types. The
   # comparisons involved are:
   #
@@ -157,6 +159,11 @@ class MIME::Type
   # 4. Current definitions < obsolete definitions.
   # 5. Obselete with use-instead references < obsolete without.
   # 6. Obsolete use-instead definitions are compared.
+  #
+  # While this method is public, its use is strongly discouraged by consumers
+  # of mime-types. In mime-types 3, this method is likely to see substantial
+  # revision and simplification to ensure current registered content types sort
+  # before unregistered or obsolete content types.
   def priority_compare(other)
     pc = simplified <=> other.simplified
     if pc.zero?
@@ -184,7 +191,7 @@ class MIME::Type
     pc
   end
 
-  # Returns +true+ if the other object is a MIME::Type and the content types
+  # Returns +true+ if the +other+ object is a MIME::Type and the content types
   # match.
   def eql?(other)
     other.kind_of?(MIME::Type) and self == other
@@ -235,12 +242,14 @@ class MIME::Type
   attr_reader :extensions
   def extensions=(ext) # :nodoc:
     @extensions = Array(ext).flatten.compact.uniq
+    # TODO: In mime-types 3.x, we probably want to have a clue about the
+    # container(s) we belong to so we can trigger reindexing when this is done.
   end
 
-  # Merge the extensions provided into this MIME::Type. The extensions added
+  # Merge the +extensions+ provided into this MIME::Type. The extensions added
   # will be merged uniquely.
-  def add_extensions(*ext)
-    self.extensions = self.extensions + ext
+  def add_extensions(*extensions)
+    self.extensions = self.extensions + extensions
   end
 
   ##
@@ -253,33 +262,39 @@ class MIME::Type
     extensions.first
   end
 
-  # The encoding (7bit, 8bit, quoted-printable, or base64) required to
-  # transport the data of this content type safely across a network, which
-  # roughly corresponds to Content-Transfer-Encoding. A value of +nil+ or
-  # <tt>:default</tt> will reset the #encoding to the #default_encoding for
-  # the MIME::Type. Raises ArgumentError if the encoding provided is
-  # invalid.
+  ##
+  # The encoding (+7bit+, +8bit+, <tt>quoted-printable</tt>, or +base64+)
+  # required to transport the data of this content type safely across a
+  # network, which roughly corresponds to Content-Transfer-Encoding. A value of
+  # +nil+ or <tt>:default</tt> will reset the #encoding to the
+  # #default_encoding for the MIME::Type. Raises ArgumentError if the encoding
+  # provided is invalid.
   #
   # If the encoding is not provided on construction, this will be either
   # 'quoted-printable' (for text/* media types) and 'base64' for eveything
   # else.
+  #
+  # :attr_accessor: encoding
+
+  ##
   attr_reader :encoding
   def encoding=(enc) # :nodoc:
     if DEFAULT_ENCODINGS.include?(enc)
-      @encoding = self.default_encoding
+      @encoding = default_encoding
     elsif BINARY_ENCODINGS.include?(enc) or TEXT_ENCODINGS.include?(enc)
       @encoding = enc
     else
-      raise InvalidEncoding, enc
+      fail InvalidEncoding, enc
     end
   end
 
   # If the MIME::Type is a system-specific MIME::Type, returns the regular
   # expression for the operating system indicated.
   #
-  # This information about MIME content types is deprecated.
+  # This information about MIME content types is deprecated and will be removed
+  # in mime-types 3.
   def system
-    MIME.deprecated(self, __method__)
+    MIME::Types.deprecated(self, __method__)
     @system
   end
 
@@ -287,7 +302,7 @@ class MIME::Type
     if os.nil? or os.kind_of?(Regexp)
       @system = os
     else
-      @system = %r|#{os}|
+      @system = %r{#{os}}
     end
   end
 
@@ -300,11 +315,17 @@ class MIME::Type
   # Returns the media type or types that should be used instead of this
   # media type, if it is obsolete. If there is no replacement media type, or
   # it is not obsolete, +nil+ will be returned.
+  #
+  # :attr_accessor: use_instead
+
+  ##
   def use_instead
     return nil unless obsolete?
     @use_instead
   end
-  attr_writer :use_instead # :nodoc:
+
+  ##
+  attr_writer :use_instead
 
   # Returns +true+ if the media type is obsolete.
   def obsolete?
@@ -323,7 +344,7 @@ class MIME::Type
   # call-seq:
   #   text_plain.friendly         # => "Text File"
   #   text_plain.friendly('en')   # => "Text File"
-  def friendly(lang = 'en')
+  def friendly(lang = 'en'.freeze)
     @friendly ||= {}
 
     case lang
@@ -334,7 +355,7 @@ class MIME::Type
     when Hash
       @friendly.merge!(lang)
     else
-      raise ArgumentError
+      fail ArgumentError
     end
   end
 
@@ -349,28 +370,59 @@ class MIME::Type
   #      # from application/x-msword
   attr_reader :i18n_key
 
+  ##
   # The encoded references URL list for this MIME::Type. See #urls for more
   # information.
   #
   # This was previously called #url.
-  attr_reader :references
+  #
+  # #references has been deprecated and both versions (#references and #url)
+  # will be removed in mime-types 3.
+  #
+  # :attr_accessor: references
+
+  ##
+  def references(__internal__ = false)
+    MIME::Types.deprecated(self, __method__) unless __internal__
+    @references
+  end
+
+  ##
   def references=(r) # :nodoc:
-    MIME.deprecated(self, __method__)
+    MIME::Types.deprecated(self, __method__)
     @references = Array(r).flatten.compact.uniq
   end
 
-  def url # :nodoc:
-    MIME.deprecated(self, __method__, "and has been renamed to #references")
-    references
+  ##
+  # The encoded references URL list for this MIME::Type. See #urls for more
+  # information.
+  #
+  # #urls has been deprecated and both versions (#references and #url) will be
+  # removed in mime-types 3.
+  #
+  # :attr_accessor: url
+
+  ##
+  def url
+    MIME::Types.deprecated(self, __method__)
+    references(true)
   end
 
+  ##
   def url=(r) # :nodoc:
-    MIME.deprecated(self, __method__)
+    MIME::Types.deprecated(self, __method__)
     self.references = r
   end
 
+  ##
   # The cross-references list for this MIME::Type.
+  #
+  # :attr_accessor: xrefs
+
+  ##
   attr_reader :xrefs
+
+  ##
   def xrefs=(x) # :nodoc:
     @xrefs = MIME::Types::Container.new.merge(x)
     @xrefs.each_value(&:sort!)
@@ -394,8 +446,11 @@ class MIME::Type
   #
   # These values will be accessible through #urls, which always returns an
   # array.
+  #
+  # This method is deprecated and will be removed in mime-types 3.
   def urls
-    references.map do |el|
+    MIME::Types.deprecated(self, __method__)
+    references(true).map do |el|
       case el
       when %r{^IANA$}
         IANA_URL % [ @media_type, @sub_type ]
@@ -417,32 +472,33 @@ class MIME::Type
 
   # The decoded cross-reference URL list for this MIME::Type.
   def xref_urls
-    xrefs.map { |(type, values)|
+    xrefs.flat_map { |(type, values)|
       case type
-      when 'rfc'
-        values.map { |data| "http://www.iana.org/go/#{data}" }
-      when 'draft'
+      when 'rfc'.freeze
+        values.map { |data| 'http://www.iana.org/go/%s'.freeze % data }
+      when 'draft'.freeze
         values.map { |data|
-          "http://www.iana.org/go/#{data.sub(/\ARFC/, 'draft')}"
+          'http://www.iana.org/go/%s'.freeze % data.sub(/\ARFC/, 'draft')
         }
-      when 'rfc-errata'
+      when 'rfc-errata'.freeze
         values.map { |data|
-          "http://www.rfc-editor.org/errata_search.php?eid=#{data}"
+          'http://www.rfc-editor.org/errata_search.php?eid=%s'.freeze % data
         }
-      when 'person'
+      when 'person'.freeze
         values.map { |data|
-          "http://www.iana.org/assignments/media-types/media-types.xhtml##{data}"
+          'http://www.iana.org/assignments/media-types/media-types.xhtml#%s'.freeze % data # rubocop:disable Metrics/LineLength
         }
-      when 'template'
+      when 'template'.freeze
         values.map { |data|
-          "http://www.iana.org/assignments/media-types/#{data}"
+          'http://www.iana.org/assignments/media-types/%s'.freeze % data
         }
       else # 'uri', 'text', etc.
         values
       end
-    }.flatten
+    }
   end
 
+  ##
   # Prior to BCP 178 (RFC 6648), it could be assumed that MIME content types
   # that start with <tt>x-</tt> were unregistered MIME. Per this BCP, this
   # assumption is no longer being made by default in this library.
@@ -453,6 +509,10 @@ class MIME::Type
   # - Unspecified, in which case the media-type and the content-type will be
   #   scanned to see if they start with <tt>x-</tt>, indicating that they
   #   are assumed unregistered.
+  #
+  # In mime-types 3, only a MIME content type that is explicitly registered
+  # will be used; there will be assumption that <tt>x-</tt> types are
+  # unregistered.
   def registered?
     if @registered.nil?
       (@raw_media_type !~ UNREGISTERED_RE) and
@@ -477,11 +537,11 @@ class MIME::Type
   # formats. This method returns +false+ when the MIME::Type encoding is
   # set to <tt>base64</tt>.
   def ascii?
-    not binary?
+    !binary?
   end
 
-  # Returns +true+ when the simplified MIME::Type is in the list of known
-  # digital signatures.
+  # Returns +true+ when the simplified MIME::Type is one of the known digital
+  # signature types.
   def signature?
     !!@signature
   end
@@ -492,25 +552,25 @@ class MIME::Type
 
   # Returns +true+ if the MIME::Type is specific to an operating system.
   #
-  # This method is deprecated.
+  # This method is deprecated and will be removed in mime-types 3.
   def system?(__internal__ = false)
-    MIME.deprecated(self, __method__) unless __internal__
-    not @system.nil?
+    MIME::Types.deprecated(self, __method__) unless __internal__
+    !@system.nil?
   end
 
   # Returns +true+ if the MIME::Type is specific to the current operating
   # system as represented by RUBY_PLATFORM.
   #
-  # This method is deprecated.
+  # This method is deprecated and will be removed in mime-types 3.
   def platform?(__internal__ = false)
-    MIME.deprecated(self, __method__) unless __internal__
+    MIME::Types.deprecated(self, __method__) unless __internal__
     system?(__internal__) and (RUBY_PLATFORM =~ @system)
   end
 
   # Returns +true+ if the MIME::Type specifies an extension list,
   # indicating that it is a complete MIME::Type.
   def complete?
-    not @extensions.empty?
+    !@extensions.empty?
   end
 
   # Returns the MIME::Type as a string.
@@ -529,9 +589,9 @@ class MIME::Type
   # Returns the MIME::Type as an array suitable for use with
   # MIME::Type.from_array.
   #
-  # This method is deprecated.
+  # This method is deprecated and will be removed in mime-types 3.
   def to_a
-    MIME.deprecated(self, __method__)
+    MIME::Types.deprecated(self, __method__)
     [ @content_type, @extensions, @encoding, @system, obsolete?, @docs,
       @references, registered? ]
   end
@@ -539,9 +599,9 @@ class MIME::Type
   # Returns the MIME::Type as an array suitable for use with
   # MIME::Type.from_hash.
   #
-  # This method is deprecated.
+  # This method is deprecated and will be removed in mime-types 3.
   def to_hash
-    MIME.deprecated(self, __method__)
+    MIME::Types.deprecated(self, __method__)
     { 'Content-Type'              => @content_type,
       'Content-Transfer-Encoding' => @encoding,
       'Extensions'                => @extensions,
@@ -555,6 +615,7 @@ class MIME::Type
 
   # Converts the MIME::Type to a JSON string.
   def to_json(*args)
+    require 'json'
     to_h.to_json(*args)
   end
 
@@ -567,6 +628,8 @@ class MIME::Type
   # Populates the +coder+ with attributes about this record for
   # serialization. The structure of +coder+ should match the structure used
   # with #init_with.
+  #
+  # This method should be considered a private implementation detail.
   def encode_with(coder)
     coder['content-type']   = @content_type
     coder['docs']           = @docs unless @docs.nil? or @docs.empty?
@@ -577,7 +640,7 @@ class MIME::Type
       coder['obsolete']     = obsolete?
       coder['use-instead']  = use_instead if use_instead
     end
-    coder['references']     = references unless references.empty?
+    coder['references']     = references(true) unless references(true).empty?
     coder['xrefs']          = xrefs unless xrefs.empty?
     coder['registered']     = registered?
     coder['signature']      = signature? if signature?
@@ -587,10 +650,12 @@ class MIME::Type
 
   # Initialize an empty object from +coder+, which must contain the
   # attributes necessary for initializing an empty object.
+  #
+  # This method should be considered a private implementation detail.
   def init_with(coder)
     self.content_type = coder['content-type']
     self.docs         = coder['docs'] || []
-    self.friendly(coder['friendly'] || {})
+    friendly(coder['friendly'] || {})
     self.encoding     = coder['encoding']
     self.extensions   = coder['extensions'] || []
     self.obsolete     = coder['obsolete']
@@ -604,14 +669,13 @@ class MIME::Type
     self.xrefs        = coder['xrefs'] || {}
     self.use_instead  = coder['use-instead']
   end
-  # :startdoc:
 
   class << self
     # The MIME types main- and sub-label can both start with <tt>x-</tt>,
     # which indicates that it is a non-registered name. Of course, after
-    # registration this flag can disappear, adds to the confusing
-    # proliferation of MIME types. The simplified string has the <tt>x-</tt>
-    # removed and are translated to lowercase.
+    # registration this flag may disappear, adds to the confusing
+    # proliferation of MIME types. The simplified +content_type+ string has the
+    # <tt>x-</tt> removed and is translated to lowercase.
     def simplified(content_type)
       matchdata = case content_type
                   when MatchData
@@ -620,16 +684,16 @@ class MIME::Type
                     MEDIA_TYPE_RE.match(content_type)
                   end
 
-      if matchdata
-        matchdata.captures.map { |e|
-          e.downcase!
-          e.gsub!(UNREGISTERED_RE, ''.freeze)
-          e
-        }.join('/'.freeze)
-      end
+      return unless matchdata
+
+      matchdata.captures.map { |e|
+        e.downcase!
+        e.gsub!(UNREGISTERED_RE, ''.freeze)
+        e
+      }.join('/'.freeze)
     end
 
-    # Converts a provided content type into a translation key suitable for
+    # Converts a provided +content_type+ into a translation key suitable for
     # use with the I18n library.
     def i18n_key(content_type)
       matchdata = case content_type
@@ -639,23 +703,23 @@ class MIME::Type
                     MEDIA_TYPE_RE.match(content_type)
                   end
 
-      if matchdata
-        matchdata.captures.map { |e|
-          e.downcase!
-          e.gsub!(UNREGISTERED_RE, ''.freeze)
-          e.gsub!(I18N_RE, '-'.freeze)
-          e
-        }.join('.'.freeze)
-      end
+      return unless matchdata
+
+      matchdata.captures.map { |e|
+        e.downcase!
+        e.gsub!(UNREGISTERED_RE, ''.freeze)
+        e.gsub!(I18N_RE, '-'.freeze)
+        e
+      }.join('.'.freeze)
     end
 
-    # Creates a MIME::Type from an array in the form of:
-    #   [type-name, [extensions], encoding, system]
+    # Creates a MIME::Type from an +args+ array in the form of:
+    #   [ type-name, [ extensions ], encoding, system ]
     #
     # +extensions+, +encoding+, and +system+ are optional.
     #
-    #   MIME::Type.from_array("application/x-ruby", ['rb'], '8bit')
-    #   MIME::Type.from_array(["application/x-ruby", ['rb'], '8bit'])
+    #   MIME::Type.from_array('application/x-ruby', %w(rb), '8bit')
+    #   MIME::Type.from_array([ 'application/x-ruby', [ 'rb' ], '8bit' ])
     #
     # These are equivalent to:
     #
@@ -664,15 +728,18 @@ class MIME::Type
     #     t.encoding    = '8bit'
     #   end
     #
-    # This method is deprecated.
-    def from_array(*args) # :yields MIME::Type.new:
-      MIME.deprecated(self, __method__)
+    # It will yield the type (+t+) if a block is given.
+    #
+    # This method is deprecated and will be removed in mime-types 3.
+    def from_array(*args) # :yields t:
+      MIME::Types.deprecated(self, __method__)
 
       # Dereferences the array one level, if necessary.
       args = args.first if args.first.kind_of? Array
 
       unless args.size.between?(1, 8)
-        raise ArgumentError, "Array provided must contain between one and eight elements."
+        fail ArgumentError,
+             'Array provided must contain between one and eight elements.'
       end
 
       MIME::Type.new(args.shift) do |t|
@@ -682,7 +749,7 @@ class MIME::Type
       end
     end
 
-    # Creates a MIME::Type from a hash. Keys are case-insensitive, dashes
+    # Creates a MIME::Type from a +hash+. Keys are case-insensitive, dashes
     # may be replaced with underscores, and the internal Symbol of the
     # lowercase-underscore version can be used as well. That is,
     # Content-Type can be provided as content-type, Content_Type,
@@ -705,9 +772,12 @@ class MIME::Type
     #     t.extensions  = ['yaml', 'yml']
     #   end
     #
-    # This method has been deprecated.
-    def from_hash(hash) # :yields MIME::Type.new:
-      MIME.deprecated(self, __method__)
+    # It will yield the constructed type +t+ if a block has been provided.
+    #
+    #
+    # This method is deprecated and will be removed in mime-types 3.
+    def from_hash(hash) # :yields t:
+      MIME::Types.deprecated(self, __method__)
       type = {}
       hash.each_pair do |k, v|
         type[k.to_s.tr('A-Z', 'a-z').gsub(/-/, '_').to_sym] = v
@@ -726,7 +796,7 @@ class MIME::Type
       end
     end
 
-    # Essentially a copy constructor.
+    # Essentially a copy constructor for +mime_type+.
     #
     #   MIME::Type.from_mime_type(plaintext)
     #
@@ -738,17 +808,20 @@ class MIME::Type
     #     t.encoding    = plaintext.encoding.dup
     #   end
     #
-    # This method has been deprecated.
+    # It will yield the type (+t+) if a block is given.
+    #
+    # This method is deprecated and will be removed in mime-types 3.
     def from_mime_type(mime_type) # :yields the new MIME::Type:
-      MIME.deprecated(self, __method__)
+      MIME::Types.deprecated(self, __method__)
       new(mime_type)
     end
   end
 
   private
+
   def content_type=(type_string)
     match = MEDIA_TYPE_RE.match(type_string)
-    raise InvalidContentType, type_string if match.nil?
+    fail InvalidContentType, type_string if match.nil?
 
     @content_type                  = type_string
     @raw_media_type, @raw_sub_type = match.captures
diff --git a/lib/mime/types.rb b/lib/mime/types.rb
index e12d8cc..2f0f66b 100644
--- a/lib/mime/types.rb
+++ b/lib/mime/types.rb
@@ -1,5 +1,6 @@
 # -*- ruby encoding: utf-8 -*-
 
+require 'mime/types/deprecations'
 require 'mime/type'
 require 'mime/types/cache'
 require 'mime/types/loader'
@@ -77,19 +78,19 @@ class MIME::Types
 
   # This method is deprecated and will be removed in mime-types 3.0.
   def add_type_variant(mime_type) # :nodoc:
-    MIME.deprecated(self, __method__, :private)
+    MIME::Types.deprecated(self, __method__, :private)
     add_type_variant!(mime_type)
   end
 
   # This method is deprecated and will be removed in mime-types 3.0.
   def index_extensions(mime_type) # :nodoc:
-    MIME.deprecated(self, __method__, :private)
+    MIME::Types.deprecated(self, __method__, :private)
     index_extensions!(mime_type)
   end
 
   # This method is deprecated and will be removed in mime-types 3.0.
   def defined_types # :nodoc:
-    MIME.deprecated(self, __method__)
+    MIME::Types.deprecated(self, __method__)
     @type_variants.values.flatten
   end
 
@@ -140,7 +141,7 @@ class MIME::Types
   # platform) is currently supported but deprecated.
   def [](type_id, flags = {})
     if flags[:platform]
-      MIME.deprecated(self, __method__, "using the :platform flag")
+      MIME::Types.deprecated(self, __method__, 'using the :platform flag')
     end
 
     matches = case type_id
@@ -176,8 +177,7 @@ class MIME::Types
     }.compact.sort { |a, b| a.priority_compare(b) }.uniq
 
     if platform
-      MIME.deprecated(self, __method__,
-                      "using the platform parameter")
+      MIME::Types.deprecated(self, __method__, 'using the platform parameter')
       types.select(&:platform?)
     else
       types
@@ -208,17 +208,18 @@ class MIME::Types
     end
   end
 
-  # Add a single MIME::Type object to the set of known types. If the type is
-  # already known, a warning will be displayed. The +quiet+ parameter may be
-  # a truthy value to suppress that warning.
-  def add_type(mime_type, quiet = false)
-    if !quiet and @type_variants[mime_type.simplified].include?(mime_type)
-      warn('Type %s is already registered as a variant of %s.' %
-           [ mime_type, mime_type.simplified ])
+  # Add a single MIME::Type object to the set of known types. If the +type+ is
+  # already known, a warning will be displayed. The +quiet+ parameter may be a
+  # truthy value to suppress that warning.
+  def add_type(type, quiet = false)
+    if !quiet and @type_variants[type.simplified].include?(type)
+      MIME::Types.logger.warn <<-warning
+Type #{type} is already registered as a variant of #{type.simplified}.
+      warning
     end
 
-    add_type_variant!(mime_type)
-    index_extensions!(mime_type)
+    add_type_variant!(type)
+    index_extensions!(type)
   end
 
   class << self
@@ -228,7 +229,7 @@ class MIME::Types
     #
     # This method has been deprecated and will be removed in mime-types 3.0.
     def load_from_file(filename)
-      MIME.deprecated(self, __method__)
+      MIME::Types.deprecated(self, __method__)
       MIME::Types::Loader.load_from_v1(filename)
     end
 
@@ -266,7 +267,7 @@ class MIME::Types
     #
     # This method has been deprecated and will be removed in mime-types 3.0.
     def cache_file
-      MIME.deprecated(self, __method__)
+      MIME::Types.deprecated(self, __method__)
       ENV['RUBY_MIME_TYPES_CACHE']
     end
 
@@ -279,6 +280,7 @@ class MIME::Types
     end
 
     private
+
     def lazy_load?
       (lazy = ENV['RUBY_MIME_TYPES_LAZY_LOAD']) && (lazy != 'false')
     end
@@ -304,6 +306,7 @@ class MIME::Types
   end
 
   private
+
   def add_type_variant!(mime_type)
     @type_variants[mime_type.simplified] << mime_type
   end
@@ -313,14 +316,14 @@ class MIME::Types
   end
 
   def prune_matches(matches, flags)
-    matches.delete_if { |e| not e.complete? } if flags[:complete]
-    matches.delete_if { |e| not e.platform? } if flags[:platform]
-    matches.delete_if { |e| not e.registered? } if flags[:registered]
+    matches.delete_if { |e| !e.complete? } if flags[:complete]
+    matches.delete_if { |e| !e.platform? } if flags[:platform]
+    matches.delete_if { |e| !e.registered? } if flags[:registered]
     matches
   end
 
   def match(pattern)
-    @type_variants.select { |k, v| k =~ pattern }.values.flatten
+    @type_variants.select { |k, _| k =~ pattern }.values.flatten
   end
 
   load_default_mime_types(load_mode) unless lazy_load?
diff --git a/lib/mime/types/cache.rb b/lib/mime/types/cache.rb
index c2e8dce..027c71d 100644
--- a/lib/mime/types/cache.rb
+++ b/lib/mime/types/cache.rb
@@ -1,6 +1,8 @@
 # -*- ruby encoding: utf-8 -*-
 
 class MIME::Types
+  Cache = Struct.new(:version, :data) # :nodoc:
+
   # Caching of MIME::Types registries is advisable if you will be loading
   # the default registry relatively frequently. With the class methods on
   # MIME::Types::Cache, any MIME::Types registry can be marshaled quickly
@@ -8,46 +10,50 @@ class MIME::Types
   #
   # The cache is invalidated on a per-version basis; a cache file for
   # version 2.0 will not be reused with version 2.0.1.
-  Cache = Struct.new(:version, :data)
-
-  class << Cache
-    # Attempts to load the cache from the file provided as a parameter or in
-    # the environment variable +RUBY_MIME_TYPES_CACHE+. Returns +nil+ if the
-    # file does not exist, if the file cannot be loaded, or if the data in
-    # the cache version is different than this version.
-    def load(cache_file = nil)
-      cache_file = cache_file || ENV['RUBY_MIME_TYPES_CACHE']
-      return nil unless cache_file and File.exist?(cache_file)
+  class Cache
+    class << self
+      # Attempts to load the cache from the file provided as a parameter or in
+      # the environment variable +RUBY_MIME_TYPES_CACHE+. Returns +nil+ if the
+      # file does not exist, if the file cannot be loaded, or if the data in
+      # the cache version is different than this version.
+      def load(cache_file = nil)
+        cache_file ||= ENV['RUBY_MIME_TYPES_CACHE']
+        return nil unless cache_file and File.exist?(cache_file)
 
-      cache = Marshal.load(File.binread(cache_file))
-      if cache.version == MIME::Types::VERSION
-        Marshal.load(cache.data)
-      else
-        warn "Could not load MIME::Types cache: invalid version"
-        nil
+        cache = Marshal.load(File.binread(cache_file))
+        if cache.version == MIME::Types::VERSION
+          Marshal.load(cache.data)
+        else
+          MIME::Types.logger.warn <<-warning.chomp
+Could not load MIME::Types cache: invalid version
+          warning
+          nil
+        end
+      rescue => e
+        MIME::Types.logger.warn <<-warning.chomp
+Could not load MIME::Types cache: #{e}
+        warning
+        return nil
       end
-    rescue => e
-      warn "Could not load MIME::Types cache: #{e}"
-      return nil
-    end
 
-    # Attempts to save the types provided to the cache file provided.
-    #
-    # If +types+ is not provided or is +nil+, the cache will contain the
-    # current MIME::Types default registry.
-    #
-    # If +cache_file+ is not provided or is +nil+, the cache will be written
-    # to the file specified in the environment variable
-    # +RUBY_MIME_TYPES_CACHE+. If there is no cache file specified either
-    # directly or through the environment, this method will return +nil+
-    def save(types = nil, cache_file = nil)
-      cache_file = cache_file || ENV['RUBY_MIME_TYPES_CACHE']
-      return nil unless cache_file
+      # Attempts to save the types provided to the cache file provided.
+      #
+      # If +types+ is not provided or is +nil+, the cache will contain the
+      # current MIME::Types default registry.
+      #
+      # If +cache_file+ is not provided or is +nil+, the cache will be written
+      # to the file specified in the environment variable
+      # +RUBY_MIME_TYPES_CACHE+. If there is no cache file specified either
+      # directly or through the environment, this method will return +nil+
+      def save(types = nil, cache_file = nil)
+        cache_file ||= ENV['RUBY_MIME_TYPES_CACHE']
+        return nil unless cache_file
 
-      types      = types || MIME::Types.send(:__types__)
+        types ||= MIME::Types.send(:__types__)
 
-      File.open(cache_file, 'wb') do |f|
-        f.write(Marshal.dump(new(types.data_version, Marshal.dump(types))))
+        File.open(cache_file, 'wb') do |f|
+          f.write(Marshal.dump(new(types.data_version, Marshal.dump(types))))
+        end
       end
     end
   end
diff --git a/lib/mime/types/columnar.rb b/lib/mime/types/columnar.rb
index 7b63651..594a727 100644
--- a/lib/mime/types/columnar.rb
+++ b/lib/mime/types/columnar.rb
@@ -13,9 +13,9 @@ require 'mime/type/columnar'
 # to an instance of MIME::Types when it is loaded with
 # MIME::Types::Loader#load_columnar.
 module MIME::Types::Columnar
-  LOAD_MUTEX = Mutex.new
+  LOAD_MUTEX = Mutex.new # :nodoc:
 
-  def self.extended(obj)
+  def self.extended(obj) # :nodoc:
     super
     obj.instance_variable_set(:@__mime_data__, [])
     obj.instance_variable_set(:@__attributes__, [])
@@ -49,7 +49,7 @@ module MIME::Types::Columnar
           line.chomp!
 
           if lookup
-            next unless type = @__mime_data__[i += 1]
+            type = @__mime_data__[i += 1] or next
             yield type, line
           else
             yield line
@@ -117,26 +117,19 @@ module MIME::Types::Columnar
   end
 
   def load_use_instead
-    empty = '-'
-    pipe = '|'
     each_file_line('use_instead') do |type, line|
       type.use_instad = (line unless line == '-'.freeze)
     end
   end
 
   def dict(line)
-    empty = '-'.freeze
-    pipe = '|'.freeze
-    caret = '^'.freeze
-
-    if line == empty
+    if line == '-'.freeze
       {}
     else
-      line.split(pipe).inject({}) { |h, l|
-        k, v = line.split(caret)
+      line.split('|'.freeze).each_with_object({}) { |h, l|
+        k, v = l.split('^'.freeze)
         v = [ nil ] if v.empty?
         h[k] = v
-        h
       }
     end
   end
diff --git a/lib/mime/types/deprecations.rb b/lib/mime/types/deprecations.rb
index 8696894..2535d34 100644
--- a/lib/mime/types/deprecations.rb
+++ b/lib/mime/types/deprecations.rb
@@ -1,45 +1,53 @@
 # -*- ruby encoding: utf-8 -*-
 
-# The namespace for MIME applications, tools, and libraries.
-module MIME # :nodoc:
-end
+require 'mime/types/logger'
 
-class << MIME
-  # Used to mark a method as deprecated in the mime-types interface.
-  def deprecated(klass, sym, message = nil, &block) # :nodoc:
-    level = case klass
-            when Class, Module
-              '.'
-            else
-              klass = klass.class
-              '#'
-            end
-    message = case message
-              when :private, :protected
-                "and will be #{message}"
-              when nil
-                "and will be removed"
+# The namespace for MIME applications, tools, and libraries.
+module MIME
+  class Types
+    # Used to mark a method as deprecated in the mime-types interface.
+    def self.deprecated(klass, sym, message = nil, &block) # :nodoc:
+      level = case klass
+              when Class, Module
+                '.'
               else
-                message
+                klass = klass.class
+                '#'
               end
-    warn "#{caller[1]}: #{klass}#{level}#{sym} is deprecated #{message}."
-    block.call if block
+      message = case message
+                when :private, :protected
+                  "and will be #{message}"
+                when nil
+                  'and will be removed'
+                else
+                  message
+                end
+      MIME::Types.logger.warn <<-warning.chomp
+#{caller[1]}: #{klass}#{level}#{sym} is deprecated #{message}.
+      warning
+      block.call if block
+    end
   end
 
-  # MIME::InvalidContentType was moved to MIME::Type::InvalidContentType.
-  # Provide a single warning about this fact in the interim.
-  def const_missing(name) # :nodoc:
-    case name.to_s
-    when "InvalidContentType"
-      warn_about_moved_constants(name)
-      MIME::Type.const_get(name.to_sym)
-    else
-      super
+  class << self
+    # MIME::InvalidContentType was moved to MIME::Type::InvalidContentType.
+    # Provide a single warning about this fact in the interim.
+    def const_missing(name) # :nodoc:
+      case name.to_s
+      when 'InvalidContentType'
+        warn_about_moved_constants(name)
+        MIME::Type.const_get(name.to_sym)
+      else
+        super
+      end
     end
-  end
 
-  private
-  def warn_about_moved_constants(name) # :nodoc:
-    warn "#{caller[1]}: MIME::#{name} is deprecated. Use MIME::Type::#{name} instead."
+    private
+
+    def warn_about_moved_constants(name)
+      MIME::Types.logger.warn <<-warning.chomp
+#{caller[1]}: MIME::#{name} is deprecated. Use MIME::Type::#{name} instead.
+      warning
+    end
   end
 end
diff --git a/lib/mime/types/loader.rb b/lib/mime/types/loader.rb
index 7833a2a..87433d0 100644
--- a/lib/mime/types/loader.rb
+++ b/lib/mime/types/loader.rb
@@ -95,9 +95,9 @@ class MIME::Types::Loader
   #
   # This method has been deprecated and will be removed from mime-types 3.0.
   def load_v1
-    MIME.deprecated(self.class, __method__)
+    MIME::Types.deprecated(self.class, __method__)
     Dir[v1_path].sort.each do |f|
-      next if f =~ /\.ya?ml$|\.json$/
+      next if f =~ /\.(?:ya?ml|json|column)$/
       container.add(self.class.load_from_v1(f, true), true)
     end
     container
@@ -152,7 +152,7 @@ class MIME::Types::Loader
     #
     # This method has been deprecated and will be removed in mime-types 3.0.
     def load_from_v1(filename, __internal__ = false)
-      MIME.deprecated(self.class, __method__) unless __internal__
+      MIME::Types.deprecated(self.class, __method__) unless __internal__
       data = read_file(filename).split($/)
       mime = MIME::Types.new
       data.each_with_index { |line, index|
@@ -162,11 +162,11 @@ class MIME::Types::Loader
         m = V1_FORMAT.match(item)
 
         unless m
-          warn <<-EOS
+          MIME::Types.logger.warn <<-EOS
 #{filename}:#{index + 1}: Parsing error in v1 MIME type definition.
 => #{line}
           EOS
-          raise BadV1Format, line
+          fail BadV1Format, line
         end
 
         unregistered, obsolete, platform, mediatype, subtype, extensions,
@@ -181,7 +181,7 @@ class MIME::Types::Loader
           use_instead = nil
         else
           use_instead = docs.scan(%r{use-instead:(\S+)}).flatten.first
-          docs = docs.gsub(%r{use-instead:\S+}, "").squeeze(" \t")
+          docs = docs.gsub(%r{use-instead:\S+}, '').squeeze(' \t')
         end
 
         mime_type = MIME::Type.new("#{mediatype}/#{subtype}") do |t|
@@ -195,7 +195,7 @@ class MIME::Types::Loader
 
           # This is being removed. Cheat to silence it for now.
           t.instance_variable_set :@references,
-            Array(urls).flatten.compact.uniq
+                                  Array(urls).flatten.compact.uniq
         end
 
         mime.add_type(mime_type, true)
@@ -233,12 +233,14 @@ class MIME::Types::Loader
     end
 
     private
+
     def read_file(filename)
       File.open(filename, 'r:UTF-8:-') { |f| f.read }
     end
   end
 
   private
+
   def yaml_path
     File.join(path, '*.y{,a}ml')
   end
diff --git a/lib/mime/types/logger.rb b/lib/mime/types/logger.rb
new file mode 100644
index 0000000..2f0b858
--- /dev/null
+++ b/lib/mime/types/logger.rb
@@ -0,0 +1,35 @@
+# -*- ruby encoding: utf-8 -*-
+
+require 'logger'
+
+module MIME
+  class Types
+    class << self
+      # Configure the MIME::Types logger. This defaults to an instance of a
+      # logger that passes messages (unformatted) through to Kernel#warn.
+      attr_accessor :logger
+    end
+
+    class WarnLogger < ::Logger #:nodoc:
+      class WarnLogDevice < ::Logger::LogDevice #:nodoc:
+        def initialize(*)
+        end
+
+        def write(m)
+          Kernel.warn(m)
+        end
+
+        def close
+        end
+      end
+
+      def initialize(_1, _2 = nil, _3 = nil)
+        super nil
+        @logdev = WarnLogDevice.new
+        @formatter = ->(_s, _d, _p, m) { m }
+      end
+    end
+
+    self.logger = WarnLogger.new(nil)
+  end
+end