Decode Nil

spec/cbor/from_cbor_spec.cr

@@ -17,6 +17,8 @@ describe "CBOR helpers on basic types" do
        Time::Format::RFC_3339.parse("2013-03-21T20:04:00Z")},
       {Time, Bytes[0xc1, 0x1a, 0x51, 0x4b, 0x67, 0xb0], Time.unix(1363896240)},
       {Time, Bytes[0xc1, 0xfb, 0x41, 0xd4, 0x52, 0xd9, 0xec, 0x20, 0x00, 0x00], Time.unix_ms((BigFloat.new(1363896240.5) * 1000).to_u64)},
+      {Nil, Bytes[0xf6], nil},
+      {Nil, Bytes[0xf7], nil},
     ]
 
     tests.each do |tt|

src/cbor/decoder.cr

@@ -58,6 +58,18 @@ class CBOR::Decoder
     end
   end
 
+  def read_nil : Nil
+    read_type(Token::SimpleValueT) do |token|
+      case token.value
+      when SimpleValue::Null,
+           SimpleValue::Undefined
+        nil
+      else
+        unexpected_token(token, "SimpleValue::Null or SimpleValue::Undefined")
+      end
+    end
+  end
+
   private def finish_token!
     @current_token = @lexer.next_token
   end

src/cbor/from_cbor.cr

@@ -23,11 +23,15 @@ def Bool.new(decoder : CBOR::Decoder)
   decoder.read_bool
 end
 
+def Nil.new(decoder : CBOR::Decoder)
+  decoder.read_nil
+end
+
 def Slice.new(decoder : CBOR::Decoder)
   decoder.read_bytes.to_slice
 end
 
-# Reads the CBOR values a time. The value must be surrounded by a time tag as
+# Reads the CBOR values as a time. The value must be surrounded by a time tag as
 # specified by [Section 2.4.1 of RFC 7049][1].
 #
 # [1]: https://tools.ietf.org/html/rfc7049#section-2.4.1