Clean ups after XML

gems/smithy-cbor/lib/smithy-cbor.rb

@@ -4,8 +4,6 @@
 
 require_relative 'smithy-cbor/builder'
 require_relative 'smithy-cbor/codec'
-require_relative 'smithy-cbor/decoder'
-require_relative 'smithy-cbor/encoder'
 require_relative 'smithy-cbor/parser'
 
 module Smithy
@@ -14,11 +12,6 @@ module Smithy
   module Cbor
     VERSION = File.read(File.expand_path('../VERSION', __dir__.to_s)).strip
 
-    # TODO: make this an instance and flatten errors
-    # def initialize(options = {})
-    #   @engine = options[:engine] || self.class.engine
-    # end
-
     # CBOR Tagged data (Major type 6).
     # A Tag consists of a tag number and a value.
     # In the extended generic data model, a tag number's definition
@@ -40,52 +33,65 @@ def initialize(tag, value)
       attr_accessor :value
     end
 
-    # Generic CBOR error, super class for specific encode/decode related errors.
-    class Error < StandardError; end
+    # Raised when a CBOR build error occurs.
+    class BuildError < StandardError; end
+
+    # Raised when a CBOR parsing error occurs.
+    class ParseError < StandardError; end
 
-    # Malformed buffer, expected more bytes
-    class OutOfBytesError < Error
-      def initialize(requested_bytes, left)
-        super("Out of bytes. Trying to read #{requested_bytes} bytes but buffer contains only #{left}")
+    class << self
+      # @param [Symbol, Class] engine
+      #   Must be one of the following values:
+      #
+      #   * :smithy
+      #
+      def engine=(engine)
+        @engine = engine.is_a?(Class) ? engine : load_engine(engine)
       end
-    end
 
-    # unknown or unsupported typed
-    class UnknownTypeError < Error
-      def initialize(type)
-        super("Unable to encode #{type}")
+      # @return [Class] Returns the default engine.
+      #   One of:
+      #
+      #   * {SmithyEngine}
+      #
+      def engine
+        set_default_engine unless @engine
+        @engine
       end
-    end
 
-    # Malformed buffer, more bytes than expected
-    class ExtraBytesError < Error
-      def initialize(pos, size)
-        super("Extra bytes follow after decoding item. Read #{pos} / #{size} bytes")
+      def encode(data)
+        @engine.encode(data)
+      end
+
+      def decode(bytes)
+        @engine.decode(bytes)
       end
-    end
 
-    # Malformed buffer, unexpected break code
-    class UnexpectedBreakCodeError < Error; end
+      def set_default_engine
+        %i[smithy].each do |name|
+          @engine ||= try_load_engine(name)
+        end
+        return if @engine
 
-    # malformed buffer, unexpected additional information
-    class UnexpectedAdditionalInformationError < Error
-      def initialize(add_info)
-        super("Unexpected additional information: #{add_info}")
+        raise 'Unable to find a compatible cbor library. ' \
+              'Ensure that you have installed or added to your Gemfile one of: smithy-cbor'
       end
-    end
 
-    class << self
-      # @param [nil, BigDecimal, Time, Tagged, String, Hash, Array] data
-      # @return [String] bytes
-      def encode(data)
-        Encoder.new.add(data).bytes
+      private
+
+      def try_load_engine(name)
+        load_engine(name)
+      rescue LoadError
+        nil
       end
 
-      # @param [String] bytes
-      # @return [nil, BigDecimal, Time, Tagged, String, Hash, Array]
-      def decode(bytes)
-        Decoder.new(bytes.force_encoding(Encoding::BINARY)).decode
+      def load_engine(name)
+        require "smithy-cbor/#{name}_engine"
+        const_name = "#{name[0].upcase}#{name[1..]}Engine"
+        const_get(const_name)
       end
     end
+
+    set_default_engine
   end
 end

gems/smithy-cbor/lib/smithy-cbor/decoder.rb

@@ -23,15 +23,14 @@ def decode
         val = decode_item
         return val unless @pos != @buffer.size
 
-        raise ExtraBytesError.new(@pos, @buffer.size)
+        raise ParseError, "Extra bytes follow after decoding item. Read #{@pos} / #{@buffer.size} bytes"
       end
 
       private
 
       # high level, generic decode. Based on the next type.
       # Consumes and returns the next item as a ruby object.
-      # rubocop:disable Metrics
-      def decode_item
+      def decode_item # rubocop:disable Metrics
         case (next_type = peek_type)
         when :array
           read_array.times.map { decode_item }
@@ -42,21 +41,20 @@ def decode_item
         when :indefinite_binary_string then process_indefinite_binary
         when :indefinite_string then process_indefinite_string
         when :tag then process_tag
-        when :break_stop_code then raise UnexpectedBreakCodeError
+        when :break_stop_code then raise ParseError, 'Unexpected break code'
         else send("read_#{next_type}")
         end
       end
-      # rubocop:enable Metrics
 
       def peek(n_bytes)
         return @buffer[@pos, n_bytes] if (@pos + n_bytes) <= @buffer.bytesize
 
-        raise OutOfBytesError.new(n_bytes, @buffer.bytesize - @pos)
+        left = @buffer.bytesize - @pos
+        raise ParseError, "Out of bytes. Trying to read #{n_bytes} bytes but buffer contains only #{left}"
       end
 
       # low level streaming interface
-      # rubocop:disable Metrics
-      def peek_type
+      def peek_type # rubocop:disable Metrics
         ib = peek(1).ord
         add_info = ib & FIVE_BIT_MASK
         major_type = ib >> 5
@@ -76,7 +74,7 @@ def peek_type
       end
 
       # simple or float
-      def process_major_type_simple(add_info)
+      def process_major_type_simple(add_info) # rubocop:disable Metrics
         case add_info
         when 20, 21 then :boolean
         when 22 then :nil
@@ -88,7 +86,6 @@ def process_major_type_simple(add_info)
         else :reserved_undefined
         end
       end
-      # rubocop:enable Metrics
 
       def process_indefinite_array
         read_start_indefinite_array
@@ -149,7 +146,7 @@ def read_array
       # See: https://www.rfc-editor.org/rfc/rfc8949.html#name-decimal-fractions-and-bigfl
       def read_big_decimal
         unless (s = read_array) == 2
-          raise Error, "Expected array of length 2 but length is: #{s}"
+          raise ParseError, "Expected array of length 2 but length is: #{s}"
         end
 
         e = read_integer
@@ -191,7 +188,7 @@ def read_count(add_info)
         when 25 then take(2).unpack1('n')
         when 26 then take(4).unpack1('N')
         when 27 then take(8).unpack1('Q>')
-        else raise UnexpectedAdditionalInformationError, add_info
+        else raise ParseError, "Unexpected additional information: #{add_info}"
         end
       end
 
@@ -293,7 +290,7 @@ def read_tag
 
       def read_reserved_undefined
         _major_type, add_info = read_info
-        raise Error, "Undefined reserved additional information: #{add_info}"
+        raise ParseError, "Undefined reserved additional information: #{add_info}"
       end
 
       def read_undefined
@@ -304,10 +301,10 @@ def read_undefined
       def take(n_bytes)
         opos = @pos
         @pos += n_bytes
-
         return @buffer[opos, n_bytes] if @pos <= @buffer.bytesize
 
-        raise OutOfBytesError.new(n_bytes, @buffer.bytesize - @pos)
+        left = @buffer.bytesize - @pos
+        raise ParseError, "Out of bytes. Trying to read #{n_bytes} bytes but buffer contains only #{left}"
       end
     end
   end

gems/smithy-cbor/lib/smithy-cbor/encoder.rb

@@ -35,8 +35,7 @@ def bytes
       end
 
       # generic method for adding generic Ruby data based on its type
-      # rubocop:disable Metrics
-      def add(value)
+      def add(value) # rubocop:disable Metrics
         case value
         when BigDecimal then add_big_decimal(value)
         when Integer then add_auto_integer(value)
@@ -49,11 +48,10 @@ def add(value)
         when Array then add_array(value)
         when Hash then add_hash(value)
         when Time then add_time(value)
-        else raise UnknownTypeError, value
+        else raise BuildError, "Unable to encode #{value}"
         end
         self
       end
-      # rubocop:enable Metrics
 
       private
 
@@ -185,7 +183,7 @@ def head(major_type, value)
           when 0...MAX_INTEGER
             [major_type + 27, value].pack('CQ>')
           else
-            raise Error, "Value is too large to encode: #{value}"
+            raise BuildError, "Value is too large to encode: #{value}"
           end
       end
 

gems/smithy-cbor/lib/smithy-cbor/parser.rb

@@ -12,7 +12,7 @@ def initialize(options = {})
         @options = options
       end
 
-      def parse(shape, bytes, target)
+      def parse(shape, bytes, target = nil)
         return {} if bytes.empty?
 
         ref = shape.is_a?(ShapeRef) ? shape : ShapeRef.new(shape: shape)

gems/smithy-cbor/lib/smithy-cbor/smithy_engine.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+require_relative 'decoder'
+require_relative 'encoder'
+
+module Smithy
+  module Cbor
+    # @api private
+    module SmithyEngine
+      class << self
+        def encode(data)
+          e = Encoder.new
+          e.add(data)
+          e.bytes
+        end
+
+        def decode(bytes)
+          d = Decoder.new(bytes.force_encoding(Encoding::BINARY))
+          d.decode
+        end
+      end
+    end
+  end
+end

gems/smithy-cbor/sig/smithy-cbor/codec.rbs

@@ -1,6 +1,7 @@
 module Smithy
   module Cbor
     module Codec
+      def initialize: (?Hash[Symbol, untyped] options) -> void
       def build: (Schema::Shapes::Shape | Schema::Shapes::ShapeRef shape, Object data) -> (nil | String)
       def parse: (Schema::Shapes::Shape | Schema::Shapes::ShapeRef shape, String bytes, ?Object ?target) -> Object?
     end