update accepted typecode range to match msgpack specification of [-128,127]

Author: zerth

src/msgpack_packer.erl

@@ -374,7 +374,7 @@ pack_map(M, Opt)->
 -spec pack_ext(any(), msgpack_ext_packer(), msgpack:options()) -> {ok, binary()} | {error, any()}.
 pack_ext(Any, Packer, Opt) ->
     case Packer(Any, Opt) of
-        {ok, {Type, Data}} when 0 < Type andalso Type < 16#100 ->
+        {ok, {Type, Data}} when -16#80 =< Type andalso Type =< 16#7F ->
             Bin = case byte_size(Data) of
                       1  -> <<16#D4, Type:8, Data/binary>>;
                       2  -> <<16#D5, Type:8, Data/binary>>;

src/msgpack_term.erl

@@ -21,7 +21,7 @@
          pack_ext/2, unpack_ext/3]).
 -behaviour(msgpack_ext).
 
--define(ERLANG_TERM, 131).
+-define(ERLANG_TERM, 127).
 -define(TERM_OPTION, [{enable_str,true},{ext,?MODULE},{allow_atom,none}]).
 
 %% @doc experimental

test/msgpack_ext_example_tests.erl

@@ -70,3 +70,28 @@ behaviour_test() ->
     Opt = [{ext, ?MODULE}],
     Term = {native, {self(), make_ref(), foobar, fun() -> ok end}},
     {ok, Term} = msgpack:unpack(msgpack:pack(Term, Opt), Opt).
+
+
+ext_typecode_range_test() ->
+    %% typecode range from msgpack spec. [-128,-1] is the "reserved"
+    %% range, [0,127] is the "user-defined" range.
+    TypecodeMin = -128,
+    TypecodeMax = 127,
+    Packer = fun ({thing, N}, _) ->
+                     {ok, {N, msgpack:pack(N)}}
+             end,
+    Unpacker = fun(_N, Bin, _) ->
+                       msgpack:unpack(Bin)
+               end,
+    Opt = [{ext,{Packer,Unpacker}}],
+    %% it should be possible to use an uncontroversial ext type code:
+    Enc = msgpack:pack({thing,1}, Opt),
+    ?assertMatch({ok, 1}, msgpack:unpack(Enc, Opt)),
+    %% it should be possible to use ext typecodes covering the entire
+    %% range specified in the msgpack specification:
+    [begin
+         Encoded = msgpack:pack({thing, N}, Opt),
+         Result = msgpack:unpack(Encoded, Opt),
+         ?assertMatch({ok, N}, Result)
+     end || N <- lists:seq(TypecodeMin,TypecodeMax)],
+    ok.