diff --git a/src/aprotobuf_decoder.erl b/src/aprotobuf_decoder.erl
index b42e52e..ea2b16e 100644
--- a/src/aprotobuf_decoder.erl
+++ b/src/aprotobuf_decoder.erl
@@ -88,10 +88,10 @@ parse(Bin, Schema, What, Acc) ->
             parse(Rest, Schema, tag, NewAcc)
     end.
 
-parse_varint(<<0:1, IntValue:7, Rest/binary>>, IntAcc, Bytes, Next, Schema, Acc) when Bytes =< 10 ->
+parse_varint(<<0:1, IntValue:7, Rest/binary>>, IntAcc, Bytes, Next, Schema, Acc) when Bytes =< 9 ->
     VarInt = (IntValue bsl 7 * Bytes) bor IntAcc,
     parse(Rest, Schema, Next, [VarInt | Acc]);
-parse_varint(<<1:1, IntValue:7, Rest/binary>>, IntAcc, Bytes, Next, Schema, Acc) when Bytes =< 10 ->
+parse_varint(<<1:1, IntValue:7, Rest/binary>>, IntAcc, Bytes, Next, Schema, Acc) when Bytes =< 9 ->
     VarInt = (IntValue bsl 7 * Bytes) bor IntAcc,
     parse_varint(Rest, VarInt, Bytes + 1, Next, Schema, Acc);
 parse_varint(Bin, _IntAcc, _Bytes, _Next, _Schema, Acc) ->
@@ -104,7 +104,23 @@ parse_fixed64(<<Fixed64:8/binary, Rest/binary>>, Next, Schema, Acc) ->
     parse(Rest, Schema, Next, [Fixed64 | Acc]).
 
 cast(Value, int32) ->
+    case Value bsr 63 of
+        0 -> Value;
+        _ -> Value - (1 bsl 64)
+    end;
+cast(Value, int64) ->
+    case Value bsr 63 of
+        0 -> Value;
+        _ -> Value - (1 bsl 64)
+    end;
+cast(Value, uint32) ->
+    Value;
+cast(Value, uint64) ->
     Value;
+cast(Value, sint32) ->
+    (Value bsr 1) bxor -(Value band 1);
+cast(Value, sint64) ->
+    (Value bsr 1) bxor -(Value band 1);
 cast(Value, {enum, IntToLabels}) ->
     case maps:find(Value, IntToLabels) of
         {ok, Label} -> Label;
@@ -114,6 +130,10 @@ cast(<<Value:32/integer-little-unsigned>>, fixed32) ->
     Value;
 cast(<<Value:32/integer-little-signed>>, sfixed32) ->
     Value;
+cast(<<Value:64/integer-little-unsigned>>, fixed64) ->
+    Value;
+cast(<<Value:64/integer-little-signed>>, sfixed64) ->
+    Value;
 cast(<<Value:32/float-little>>, float) ->
     Value;
 cast(Value, undefined) ->
diff --git a/src/aprotobuf_encoder.erl b/src/aprotobuf_encoder.erl
index 0573afa..de0231e 100644
--- a/src/aprotobuf_encoder.erl
+++ b/src/aprotobuf_encoder.erl
@@ -23,6 +23,7 @@
 
 -define(LEN_TAG, 2).
 -define(FIXED32_TAG, 5).
+-define(FIXED64_TAG, 1).
 
 encode(Map, Schema) ->
     Iterator = maps:iterator(Map),
@@ -43,10 +44,50 @@ encode_field(FieldNum, V, string) ->
 encode_field(FieldNum, V, {enum, LabelsToInt}) ->
     IntVal = maps:get(V, LabelsToInt),
     [encode_varint(FieldNum bsl 3), encode_varint(IntVal)];
-encode_field(FieldNum, V, int32) ->
+encode_field(FieldNum, V, int32) when is_integer(V), V >= 0, V < (1 bsl 31) ->
     [encode_varint(FieldNum bsl 3), encode_varint(V)];
+encode_field(FieldNum, V, int32) when is_integer(V), V < 0, V >= -(1 bsl 31) ->
+    [encode_varint(FieldNum bsl 3), encode_varint(V band 16#FFFFFFFFFFFFFFFF)];
+encode_field(_FieldNum, _V, int32) ->
+    error(badarg);
+encode_field(FieldNum, V, int64) when is_integer(V), V >= 0, V < (1 bsl 63) ->
+    [encode_varint(FieldNum bsl 3), encode_varint(V)];
+encode_field(FieldNum, V, int64) when is_integer(V), V < 0, V >= -(1 bsl 63) ->
+    [encode_varint(FieldNum bsl 3), encode_varint(V band 16#FFFFFFFFFFFFFFFF)];
+encode_field(_FieldNum, _V, int64) ->
+    error(badarg);
+encode_field(FieldNum, V, uint32) when is_integer(V), V >= 0, V < (1 bsl 32) ->
+    [encode_varint(FieldNum bsl 3), encode_varint(V)];
+encode_field(_FieldNum, _V, uint32) ->
+    error(badarg);
+encode_field(FieldNum, V, uint64) when is_integer(V), V >= 0, V < (1 bsl 64) ->
+    [encode_varint(FieldNum bsl 3), encode_varint(V)];
+encode_field(_FieldNum, _V, uint64) ->
+    error(badarg);
+encode_field(FieldNum, V, sint32) when is_integer(V), V >= -(1 bsl 31), V < (1 bsl 31) ->
+    Z = ((V bsl 1) bxor (V bsr 31)) band 16#FFFFFFFF,
+    [encode_varint(FieldNum bsl 3), encode_varint(Z)];
+encode_field(_FieldNum, _V, sint32) ->
+    error(badarg);
+encode_field(FieldNum, V, sint64) when is_integer(V), V >= -(1 bsl 63), V < (1 bsl 63) ->
+    Z = ((V bsl 1) bxor (V bsr 63)) band 16#FFFFFFFFFFFFFFFF,
+    [encode_varint(FieldNum bsl 3), encode_varint(Z)];
+encode_field(_FieldNum, _V, sint64) ->
+    error(badarg);
 encode_field(FieldNum, V, sfixed32) ->
     [encode_varint((FieldNum bsl 3) bor ?FIXED32_TAG), encode_sfixed32(V)];
+encode_field(FieldNum, V, fixed32) when is_integer(V), V >= 0, V < (1 bsl 32) ->
+    [encode_varint((FieldNum bsl 3) bor ?FIXED32_TAG), encode_fixed32(V)];
+encode_field(_FieldNum, _V, fixed32) ->
+    error(badarg);
+encode_field(FieldNum, V, fixed64) when is_integer(V), V >= 0, V < (1 bsl 64) ->
+    [encode_varint((FieldNum bsl 3) bor ?FIXED64_TAG), encode_fixed64(V)];
+encode_field(_FieldNum, _V, fixed64) ->
+    error(badarg);
+encode_field(FieldNum, V, sfixed64) when is_integer(V), V >= -(1 bsl 63), V < (1 bsl 63) ->
+    [encode_varint((FieldNum bsl 3) bor ?FIXED64_TAG), encode_sfixed64(V)];
+encode_field(_FieldNum, _V, sfixed64) ->
+    error(badarg);
 encode_field(FieldNum, V, MapSchema) when is_map(MapSchema) ->
     Encoded = encode(V, MapSchema),
     Len = erlang:iolist_size(Encoded),
@@ -57,37 +98,23 @@ encode_field(_FiledNum, _V, _Type) ->
 encode_sfixed32(Int) ->
     <<Int:32/little-signed-integer>>.
 
-% TODO: right now we focus to positive ints up to UINT32_MAX and something
-encode_varint(Int) when Int < 0 ->
-    error(badarg);
-% 2^7 - 1
-encode_varint(Int) when Int =< 127 ->
+encode_fixed32(Int) ->
+    <<Int:32/little-unsigned-integer>>.
+
+encode_fixed64(Int) ->
+    <<Int:64/little-unsigned-integer>>.
+
+encode_sfixed64(Int) ->
+    <<Int:64/little-signed-integer>>.
+
+encode_varint(Int) when is_integer(Int), Int >= 0, Int < 128 ->
     [Int];
-% 2^14 - 1
-encode_varint(Int) when Int =< 16383 ->
-    Int0 = Int band 16#7F,
-    Int1 = Int bsr 7,
-    <<1:1, Int0:7, 0:1, Int1:7>>;
-% 2^21 - 1
-encode_varint(Int) when Int =< 2097151 ->
-    Int0 = Int band 16#7F,
-    Int1 = (Int bsr 7) band 16#7F,
-    Int2 = Int bsr 14,
-    <<1:1, Int0:7, 1:1, Int1:7, 0:1, Int2:7>>;
-% 2^28 - 1
-encode_varint(Int) when Int =< 268435456 ->
-    Int0 = Int band 16#7F,
-    Int1 = (Int bsr 7) band 16#7F,
-    Int2 = (Int bsr 14) band 16#7F,
-    Int3 = Int bsr 21,
-    <<1:1, Int0:7, 0:1, Int1:7, 0:1, Int2:7, 0:1, Int3:7>>;
-% 2^35 - 1
-encode_varint(Int) when Int =< 34359738367 ->
-    Int0 = Int band 16#7F,
-    Int1 = (Int bsr 7) band 16#7F,
-    Int2 = (Int bsr 14) band 16#7F,
-    Int3 = (Int bsr 21) band 16#7F,
-    Int4 = Int bsr 28,
-    <<1:1, Int0:7, 1:1, Int1:7, 1:1, Int2:7, 1:1, Int3:7, 0:1, Int4:7>>;
+encode_varint(Int) when is_integer(Int), Int >= 128, Int < (1 bsl 64) ->
+    encode_varint_more(Int);
 encode_varint(_Int) ->
     error(badarg).
+
+encode_varint_more(Int) when Int < 128 ->
+    [Int];
+encode_varint_more(Int) ->
+    [(Int band 16#7F) bor 16#80 | encode_varint_more(Int bsr 7)].
diff --git a/test/aprotobuf_decoder_test.erl b/test/aprotobuf_decoder_test.erl
index ad57479..ffb633a 100644
--- a/test/aprotobuf_decoder_test.erl
+++ b/test/aprotobuf_decoder_test.erl
@@ -98,3 +98,677 @@ decode_int32_string_int32_message_test() ->
         #{b => 5, c => <<"Hello World">>, d => 1989},
         aprotobuf_decoder:parse(Encoded, DecoderSchema)
     ).
+
+decode_int32_max_test() ->
+    Schema = #{
+        a => {1, int32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 2147483647},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#FF, 16#FF, 16#FF, 16#FF, 16#07>>, DecoderSchema
+        )
+    ).
+
+decode_int32_minus_one_test() ->
+    Schema = #{
+        a => {1, int32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -1},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#01>>,
+            DecoderSchema
+        )
+    ).
+
+decode_int32_minus_42_test() ->
+    Schema = #{
+        a => {1, int32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -42},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#D6, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#01>>,
+            DecoderSchema
+        )
+    ).
+
+decode_int32_min_test() ->
+    Schema = #{
+        a => {1, int32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -2147483648},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#80, 16#80, 16#80, 16#80, 16#F8, 16#FF, 16#FF, 16#FF, 16#FF, 16#01>>,
+            DecoderSchema
+        )
+    ).
+
+decode_int64_two_to_31_test() ->
+    Schema = #{
+        a => {1, int64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 2147483648},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#80, 16#80, 16#80, 16#80, 16#08>>, DecoderSchema
+        )
+    ).
+
+decode_int64_max_test() ->
+    Schema = #{
+        a => {1, int64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 9223372036854775807},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#7F>>,
+            DecoderSchema
+        )
+    ).
+
+decode_int64_minus_one_test() ->
+    Schema = #{
+        a => {1, int64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -1},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#01>>,
+            DecoderSchema
+        )
+    ).
+
+decode_int64_minus_42_test() ->
+    Schema = #{
+        a => {1, int64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -42},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#D6, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#01>>,
+            DecoderSchema
+        )
+    ).
+
+decode_int64_min_test() ->
+    Schema = #{
+        a => {1, int64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -9223372036854775808},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#80, 16#80, 16#80, 16#80, 16#80, 16#80, 16#80, 16#80, 16#80, 16#01>>,
+            DecoderSchema
+        )
+    ).
+
+decode_int64_complex_test() ->
+    Schema = #{
+        a => {1, int64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -16#ABCD1234560CAFE},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#82, 16#EA, 16#FC, 16#D4, 16#CB, 16#DB, 16#CB, 16#A1, 16#F5, 16#01>>,
+            DecoderSchema
+        )
+    ).
+
+decode_uint32_small_test() ->
+    Schema = #{
+        a => {1, uint32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(#{a => 42}, aprotobuf_decoder:parse(<<16#08, 16#2A>>, DecoderSchema)).
+
+decode_uint32_two_to_31_test() ->
+    Schema = #{
+        a => {1, uint32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 2147483648},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#80, 16#80, 16#80, 16#80, 16#08>>, DecoderSchema
+        )
+    ).
+
+decode_uint32_max_test() ->
+    Schema = #{
+        a => {1, uint32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 4294967295},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#FF, 16#FF, 16#FF, 16#FF, 16#0F>>, DecoderSchema
+        )
+    ).
+
+decode_uint64_small_test() ->
+    Schema = #{
+        a => {1, uint64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(#{a => 42}, aprotobuf_decoder:parse(<<16#08, 16#2A>>, DecoderSchema)).
+
+decode_uint64_two_to_32_test() ->
+    Schema = #{
+        a => {1, uint64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 4294967296},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#80, 16#80, 16#80, 16#80, 16#10>>, DecoderSchema
+        )
+    ).
+
+decode_uint64_max_test() ->
+    Schema = #{
+        a => {1, uint64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 18446744073709551615},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#01>>,
+            DecoderSchema
+        )
+    ).
+
+decode_uint64_complex_test() ->
+    Schema = #{
+        a => {1, uint64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 16#ABCD1234560CAFE},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#FE, 16#95, 16#83, 16#AB, 16#B4, 16#A4, 16#B4, 16#DE, 16#0A>>,
+            DecoderSchema
+        )
+    ).
+
+decode_sint32_minus_one_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(#{a => -1}, aprotobuf_decoder:parse(<<16#08, 16#01>>, DecoderSchema)).
+
+decode_sint32_minus_42_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(#{a => -42}, aprotobuf_decoder:parse(<<16#08, 16#53>>, DecoderSchema)).
+
+decode_sint32_max_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 2147483647},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#FE, 16#FF, 16#FF, 16#FF, 16#0F>>, DecoderSchema
+        )
+    ).
+
+decode_sint32_min_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -2147483648},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#FF, 16#FF, 16#FF, 16#FF, 16#0F>>, DecoderSchema
+        )
+    ).
+
+decode_sint32_complex_pos_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 16#6CAFE123},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#C6, 16#84, 16#FF, 16#CA, 16#0D>>, DecoderSchema
+        )
+    ).
+
+decode_sint32_complex_neg_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -16#11CAFE01},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#81, 16#F8, 16#D7, 16#9C, 16#02>>, DecoderSchema
+        )
+    ).
+
+decode_sint32_zero_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(#{a => 0}, aprotobuf_decoder:parse(<<16#08, 16#00>>, DecoderSchema)).
+
+decode_sint32_one_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(#{a => 1}, aprotobuf_decoder:parse(<<16#08, 16#02>>, DecoderSchema)).
+
+decode_sint32_42_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(#{a => 42}, aprotobuf_decoder:parse(<<16#08, 16#54>>, DecoderSchema)).
+
+decode_sint32_1000_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 1000},
+        aprotobuf_decoder:parse(<<16#08, 16#D0, 16#0F>>, DecoderSchema)
+    ).
+
+decode_sint32_minus_1000_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -1000},
+        aprotobuf_decoder:parse(<<16#08, 16#CF, 16#0F>>, DecoderSchema)
+    ).
+
+decode_sint32_66000_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 66000},
+        aprotobuf_decoder:parse(<<16#08, 16#A0, 16#87, 16#08>>, DecoderSchema)
+    ).
+
+decode_sint32_minus_66000_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -66000},
+        aprotobuf_decoder:parse(<<16#08, 16#9F, 16#87, 16#08>>, DecoderSchema)
+    ).
+
+decode_sint64_minus_one_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(#{a => -1}, aprotobuf_decoder:parse(<<16#08, 16#01>>, DecoderSchema)).
+
+decode_sint64_minus_42_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(#{a => -42}, aprotobuf_decoder:parse(<<16#08, 16#53>>, DecoderSchema)).
+
+decode_sint64_max_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 9223372036854775807},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#FE, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#01>>,
+            DecoderSchema
+        )
+    ).
+
+decode_sint64_min_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -9223372036854775808},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#01>>,
+            DecoderSchema
+        )
+    ).
+
+decode_sint64_complex_pos_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 16#6543CAFE1234ABCD},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#9A, 16#AF, 16#A5, 16#A3, 16#C2, 16#BF, 16#E5, 16#C3, 16#CA, 16#01>>,
+            DecoderSchema
+        )
+    ).
+
+decode_sint64_complex_neg_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -16#1234CAFE9876ABCD},
+        aprotobuf_decoder:parse(
+            <<16#08, 16#99, 16#AF, 16#B5, 16#87, 16#D3, 16#BF, 16#E5, 16#B4, 16#24>>,
+            DecoderSchema
+        )
+    ).
+
+decode_sint64_zero_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(#{a => 0}, aprotobuf_decoder:parse(<<16#08, 16#00>>, DecoderSchema)).
+
+decode_sint64_one_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(#{a => 1}, aprotobuf_decoder:parse(<<16#08, 16#02>>, DecoderSchema)).
+
+decode_sint64_42_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(#{a => 42}, aprotobuf_decoder:parse(<<16#08, 16#54>>, DecoderSchema)).
+
+decode_sint64_1000_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 1000},
+        aprotobuf_decoder:parse(<<16#08, 16#D0, 16#0F>>, DecoderSchema)
+    ).
+
+decode_sint64_minus_1000_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -1000},
+        aprotobuf_decoder:parse(<<16#08, 16#CF, 16#0F>>, DecoderSchema)
+    ).
+
+decode_sint64_66000_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 66000},
+        aprotobuf_decoder:parse(<<16#08, 16#A0, 16#87, 16#08>>, DecoderSchema)
+    ).
+
+decode_sint64_minus_66000_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -66000},
+        aprotobuf_decoder:parse(<<16#08, 16#9F, 16#87, 16#08>>, DecoderSchema)
+    ).
+
+decode_fixed32_zero_test() ->
+    Schema = #{
+        a => {1, fixed32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 0},
+        aprotobuf_decoder:parse(<<16#0D, 16#00, 16#00, 16#00, 16#00>>, DecoderSchema)
+    ).
+
+decode_fixed32_small_test() ->
+    Schema = #{
+        a => {1, fixed32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 42},
+        aprotobuf_decoder:parse(<<16#0D, 16#2A, 16#00, 16#00, 16#00>>, DecoderSchema)
+    ).
+
+decode_fixed32_max_test() ->
+    Schema = #{
+        a => {1, fixed32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 4294967295},
+        aprotobuf_decoder:parse(<<16#0D, 16#FF, 16#FF, 16#FF, 16#FF>>, DecoderSchema)
+    ).
+
+decode_fixed32_complex_test() ->
+    Schema = #{
+        a => {1, fixed32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 16#DEADBEEF},
+        aprotobuf_decoder:parse(<<16#0D, 16#EF, 16#BE, 16#AD, 16#DE>>, DecoderSchema)
+    ).
+
+decode_sfixed32_zero_test() ->
+    Schema = #{
+        a => {1, sfixed32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 0},
+        aprotobuf_decoder:parse(<<16#0D, 16#00, 16#00, 16#00, 16#00>>, DecoderSchema)
+    ).
+
+decode_sfixed32_small_test() ->
+    Schema = #{
+        a => {1, sfixed32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 42},
+        aprotobuf_decoder:parse(<<16#0D, 16#2A, 16#00, 16#00, 16#00>>, DecoderSchema)
+    ).
+
+decode_sfixed32_minus_one_test() ->
+    Schema = #{
+        a => {1, sfixed32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -1},
+        aprotobuf_decoder:parse(<<16#0D, 16#FF, 16#FF, 16#FF, 16#FF>>, DecoderSchema)
+    ).
+
+decode_sfixed32_minus_42_test() ->
+    Schema = #{
+        a => {1, sfixed32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -42},
+        aprotobuf_decoder:parse(<<16#0D, 16#D6, 16#FF, 16#FF, 16#FF>>, DecoderSchema)
+    ).
+
+decode_sfixed32_max_test() ->
+    Schema = #{
+        a => {1, sfixed32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 2147483647},
+        aprotobuf_decoder:parse(<<16#0D, 16#FF, 16#FF, 16#FF, 16#7F>>, DecoderSchema)
+    ).
+
+decode_sfixed32_min_test() ->
+    Schema = #{
+        a => {1, sfixed32}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -2147483648},
+        aprotobuf_decoder:parse(<<16#0D, 16#00, 16#00, 16#00, 16#80>>, DecoderSchema)
+    ).
+
+decode_fixed64_zero_test() ->
+    Schema = #{
+        a => {1, fixed64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 0},
+        aprotobuf_decoder:parse(
+            <<16#09, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00>>, DecoderSchema
+        )
+    ).
+
+decode_fixed64_small_test() ->
+    Schema = #{
+        a => {1, fixed64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 42},
+        aprotobuf_decoder:parse(
+            <<16#09, 16#2A, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00>>, DecoderSchema
+        )
+    ).
+
+decode_fixed64_max_test() ->
+    Schema = #{
+        a => {1, fixed64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 18446744073709551615},
+        aprotobuf_decoder:parse(
+            <<16#09, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF>>, DecoderSchema
+        )
+    ).
+
+decode_fixed64_complex_test() ->
+    Schema = #{
+        a => {1, fixed64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 16#DEADBEEFCAFE1234},
+        aprotobuf_decoder:parse(
+            <<16#09, 16#34, 16#12, 16#FE, 16#CA, 16#EF, 16#BE, 16#AD, 16#DE>>, DecoderSchema
+        )
+    ).
+
+decode_sfixed64_zero_test() ->
+    Schema = #{
+        a => {1, sfixed64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 0},
+        aprotobuf_decoder:parse(
+            <<16#09, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00>>, DecoderSchema
+        )
+    ).
+
+decode_sfixed64_small_test() ->
+    Schema = #{
+        a => {1, sfixed64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 42},
+        aprotobuf_decoder:parse(
+            <<16#09, 16#2A, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00>>, DecoderSchema
+        )
+    ).
+
+decode_sfixed64_minus_one_test() ->
+    Schema = #{
+        a => {1, sfixed64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -1},
+        aprotobuf_decoder:parse(
+            <<16#09, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF>>, DecoderSchema
+        )
+    ).
+
+decode_sfixed64_minus_42_test() ->
+    Schema = #{
+        a => {1, sfixed64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -42},
+        aprotobuf_decoder:parse(
+            <<16#09, 16#D6, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF>>, DecoderSchema
+        )
+    ).
+
+decode_sfixed64_max_test() ->
+    Schema = #{
+        a => {1, sfixed64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => 9223372036854775807},
+        aprotobuf_decoder:parse(
+            <<16#09, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#7F>>, DecoderSchema
+        )
+    ).
+
+decode_sfixed64_min_test() ->
+    Schema = #{
+        a => {1, sfixed64}
+    },
+    DecoderSchema = aprotobuf_decoder:transform_schema(Schema),
+    ?assertEqual(
+        #{a => -9223372036854775808},
+        aprotobuf_decoder:parse(
+            <<16#09, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00, 16#80>>, DecoderSchema
+        )
+    ).
diff --git a/test/aprotobuf_encoder_test.erl b/test/aprotobuf_encoder_test.erl
new file mode 100644
index 0000000..262e630
--- /dev/null
+++ b/test/aprotobuf_encoder_test.erl
@@ -0,0 +1,722 @@
+%
+% This file is part of aprotobuf.
+%
+% Copyright 2023 Davide Bettio <davide@uninstall.it>
+%
+% Licensed under the Apache License, Version 2.0 (the "License");
+% you may not use this file except in compliance with the License.
+% You may obtain a copy of the License at
+%
+%    http://www.apache.org/licenses/LICENSE-2.0
+%
+% Unless required by applicable law or agreed to in writing, software
+% distributed under the License is distributed on an "AS IS" BASIS,
+% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+% See the License for the specific language governing permissions and
+% limitations under the License.
+%
+% SPDX-License-Identifier: Apache-2.0
+%
+
+-module(aprotobuf_encoder_test).
+
+-include_lib("eunit/include/eunit.hrl").
+
+encode_int32_small_test() ->
+    Schema = #{
+        a => {1, int32}
+    },
+    ?assertEqual(
+        <<16#08, 16#2A>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 42}, Schema))
+    ).
+
+encode_int32_two_to_21_test() ->
+    Schema = #{
+        a => {1, int32}
+    },
+    ?assertEqual(
+        <<16#08, 16#80, 16#80, 16#80, 16#01>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 2097152}, Schema))
+    ).
+
+encode_int32_two_to_28_minus_one_test() ->
+    Schema = #{
+        a => {1, int32}
+    },
+    ?assertEqual(
+        <<16#08, 16#FF, 16#FF, 16#FF, 16#7F>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 268435455}, Schema))
+    ).
+
+encode_int32_two_to_28_test() ->
+    Schema = #{
+        a => {1, int32}
+    },
+    ?assertEqual(
+        <<16#08, 16#80, 16#80, 16#80, 16#80, 16#01>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 268435456}, Schema))
+    ).
+
+encode_int32_minus_one_test() ->
+    Schema = #{
+        a => {1, int32}
+    },
+    ?assertEqual(
+        <<16#08, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#01>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -1}, Schema))
+    ).
+
+encode_int32_minus_42_test() ->
+    Schema = #{
+        a => {1, int32}
+    },
+    ?assertEqual(
+        <<16#08, 16#D6, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#01>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -42}, Schema))
+    ).
+
+encode_int32_min_test() ->
+    Schema = #{
+        a => {1, int32}
+    },
+    ?assertEqual(
+        <<16#08, 16#80, 16#80, 16#80, 16#80, 16#F8, 16#FF, 16#FF, 16#FF, 16#FF, 16#01>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -2147483648}, Schema))
+    ).
+
+encode_int32_overflow_test() ->
+    Schema = #{
+        a => {1, int32}
+    },
+    ?assertError(badarg, aprotobuf_encoder:encode(#{a => 2147483648}, Schema)).
+
+encode_int32_underflow_test() ->
+    Schema = #{
+        a => {1, int32}
+    },
+    ?assertError(badarg, aprotobuf_encoder:encode(#{a => -2147483649}, Schema)).
+
+encode_int64_small_test() ->
+    Schema = #{
+        a => {1, int64}
+    },
+    ?assertEqual(
+        <<16#08, 16#2A>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 42}, Schema))
+    ).
+
+encode_int64_two_to_31_test() ->
+    Schema = #{
+        a => {1, int64}
+    },
+    ?assertEqual(
+        <<16#08, 16#80, 16#80, 16#80, 16#80, 16#08>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 2147483648}, Schema))
+    ).
+
+encode_int64_max_test() ->
+    Schema = #{
+        a => {1, int64}
+    },
+    ?assertEqual(
+        <<16#08, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#7F>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 9223372036854775807}, Schema))
+    ).
+
+encode_int64_minus_one_test() ->
+    Schema = #{
+        a => {1, int64}
+    },
+    ?assertEqual(
+        <<16#08, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#01>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -1}, Schema))
+    ).
+
+encode_int64_minus_42_test() ->
+    Schema = #{
+        a => {1, int64}
+    },
+    ?assertEqual(
+        <<16#08, 16#D6, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#01>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -42}, Schema))
+    ).
+
+encode_int64_min_test() ->
+    Schema = #{
+        a => {1, int64}
+    },
+    ?assertEqual(
+        <<16#08, 16#80, 16#80, 16#80, 16#80, 16#80, 16#80, 16#80, 16#80, 16#80, 16#01>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -9223372036854775808}, Schema))
+    ).
+
+encode_int64_overflow_test() ->
+    Schema = #{
+        a => {1, int64}
+    },
+    ?assertError(badarg, aprotobuf_encoder:encode(#{a => 9223372036854775808}, Schema)).
+
+encode_int64_underflow_test() ->
+    Schema = #{
+        a => {1, int64}
+    },
+    ?assertError(badarg, aprotobuf_encoder:encode(#{a => -9223372036854775809}, Schema)).
+
+encode_int64_complex_test() ->
+    Schema = #{
+        a => {1, int64}
+    },
+    ?assertEqual(
+        <<16#08, 16#82, 16#EA, 16#FC, 16#D4, 16#CB, 16#DB, 16#CB, 16#A1, 16#F5, 16#01>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -16#ABCD1234560CAFE}, Schema))
+    ).
+
+encode_uint32_small_test() ->
+    Schema = #{
+        a => {1, uint32}
+    },
+    ?assertEqual(
+        <<16#08, 16#2A>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 42}, Schema))
+    ).
+
+encode_uint32_two_to_31_test() ->
+    Schema = #{
+        a => {1, uint32}
+    },
+    ?assertEqual(
+        <<16#08, 16#80, 16#80, 16#80, 16#80, 16#08>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 2147483648}, Schema))
+    ).
+
+encode_uint32_max_test() ->
+    Schema = #{
+        a => {1, uint32}
+    },
+    ?assertEqual(
+        <<16#08, 16#FF, 16#FF, 16#FF, 16#FF, 16#0F>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 4294967295}, Schema))
+    ).
+
+encode_uint32_overflow_test() ->
+    Schema = #{
+        a => {1, uint32}
+    },
+    ?assertError(badarg, aprotobuf_encoder:encode(#{a => 4294967296}, Schema)).
+
+encode_uint32_underflow_test() ->
+    Schema = #{
+        a => {1, uint32}
+    },
+    ?assertError(badarg, aprotobuf_encoder:encode(#{a => -1}, Schema)).
+
+encode_uint64_small_test() ->
+    Schema = #{
+        a => {1, uint64}
+    },
+    ?assertEqual(
+        <<16#08, 16#2A>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 42}, Schema))
+    ).
+
+encode_uint64_two_to_32_test() ->
+    Schema = #{
+        a => {1, uint64}
+    },
+    ?assertEqual(
+        <<16#08, 16#80, 16#80, 16#80, 16#80, 16#10>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 4294967296}, Schema))
+    ).
+
+encode_uint64_max_test() ->
+    Schema = #{
+        a => {1, uint64}
+    },
+    ?assertEqual(
+        <<16#08, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#01>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 18446744073709551615}, Schema))
+    ).
+
+encode_uint64_overflow_test() ->
+    Schema = #{
+        a => {1, uint64}
+    },
+    ?assertError(badarg, aprotobuf_encoder:encode(#{a => 18446744073709551616}, Schema)).
+
+encode_uint64_underflow_test() ->
+    Schema = #{
+        a => {1, uint64}
+    },
+    ?assertError(badarg, aprotobuf_encoder:encode(#{a => -1}, Schema)).
+
+encode_uint64_complex_test() ->
+    Schema = #{
+        a => {1, uint64}
+    },
+    ?assertEqual(
+        <<16#08, 16#FE, 16#95, 16#83, 16#AB, 16#B4, 16#A4, 16#B4, 16#DE, 16#0A>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 16#ABCD1234560CAFE}, Schema))
+    ).
+
+encode_sint32_small_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    ?assertEqual(
+        <<16#08, 16#54>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 42}, Schema))
+    ).
+
+encode_sint32_minus_one_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    ?assertEqual(
+        <<16#08, 16#01>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -1}, Schema))
+    ).
+
+encode_sint32_minus_42_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    ?assertEqual(
+        <<16#08, 16#53>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -42}, Schema))
+    ).
+
+encode_sint32_max_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    ?assertEqual(
+        <<16#08, 16#FE, 16#FF, 16#FF, 16#FF, 16#0F>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 2147483647}, Schema))
+    ).
+
+encode_sint32_min_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    ?assertEqual(
+        <<16#08, 16#FF, 16#FF, 16#FF, 16#FF, 16#0F>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -2147483648}, Schema))
+    ).
+
+encode_sint32_overflow_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    ?assertError(badarg, aprotobuf_encoder:encode(#{a => 2147483648}, Schema)).
+
+encode_sint32_underflow_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    ?assertError(badarg, aprotobuf_encoder:encode(#{a => -2147483649}, Schema)).
+
+encode_sint32_complex_pos_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    ?assertEqual(
+        <<16#08, 16#C6, 16#84, 16#FF, 16#CA, 16#0D>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 16#6CAFE123}, Schema))
+    ).
+
+encode_sint32_complex_neg_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    ?assertEqual(
+        <<16#08, 16#81, 16#F8, 16#D7, 16#9C, 16#02>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -16#11CAFE01}, Schema))
+    ).
+
+encode_sint32_zero_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    ?assertEqual(
+        <<16#08, 16#00>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 0}, Schema))
+    ).
+
+encode_sint32_one_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    ?assertEqual(
+        <<16#08, 16#02>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 1}, Schema))
+    ).
+
+encode_sint32_1000_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    ?assertEqual(
+        <<16#08, 16#D0, 16#0F>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 1000}, Schema))
+    ).
+
+encode_sint32_minus_1000_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    ?assertEqual(
+        <<16#08, 16#CF, 16#0F>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -1000}, Schema))
+    ).
+
+encode_sint32_66000_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    ?assertEqual(
+        <<16#08, 16#A0, 16#87, 16#08>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 66000}, Schema))
+    ).
+
+encode_sint32_minus_66000_test() ->
+    Schema = #{
+        a => {1, sint32}
+    },
+    ?assertEqual(
+        <<16#08, 16#9F, 16#87, 16#08>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -66000}, Schema))
+    ).
+
+encode_sint64_small_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    ?assertEqual(
+        <<16#08, 16#54>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 42}, Schema))
+    ).
+
+encode_sint64_minus_one_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    ?assertEqual(
+        <<16#08, 16#01>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -1}, Schema))
+    ).
+
+encode_sint64_minus_42_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    ?assertEqual(
+        <<16#08, 16#53>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -42}, Schema))
+    ).
+
+encode_sint64_max_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    ?assertEqual(
+        <<16#08, 16#FE, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#01>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 9223372036854775807}, Schema))
+    ).
+
+encode_sint64_min_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    ?assertEqual(
+        <<16#08, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#01>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -9223372036854775808}, Schema))
+    ).
+
+encode_sint64_overflow_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    ?assertError(badarg, aprotobuf_encoder:encode(#{a => 9223372036854775808}, Schema)).
+
+encode_sint64_underflow_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    ?assertError(badarg, aprotobuf_encoder:encode(#{a => -9223372036854775809}, Schema)).
+
+encode_sint64_complex_pos_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    ?assertEqual(
+        <<16#08, 16#9A, 16#AF, 16#A5, 16#A3, 16#C2, 16#BF, 16#E5, 16#C3, 16#CA, 16#01>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 16#6543CAFE1234ABCD}, Schema))
+    ).
+
+encode_sint64_complex_neg_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    ?assertEqual(
+        <<16#08, 16#99, 16#AF, 16#B5, 16#87, 16#D3, 16#BF, 16#E5, 16#B4, 16#24>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -16#1234CAFE9876ABCD}, Schema))
+    ).
+
+encode_sint64_zero_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    ?assertEqual(
+        <<16#08, 16#00>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 0}, Schema))
+    ).
+
+encode_sint64_one_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    ?assertEqual(
+        <<16#08, 16#02>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 1}, Schema))
+    ).
+
+encode_sint64_1000_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    ?assertEqual(
+        <<16#08, 16#D0, 16#0F>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 1000}, Schema))
+    ).
+
+encode_sint64_minus_1000_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    ?assertEqual(
+        <<16#08, 16#CF, 16#0F>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -1000}, Schema))
+    ).
+
+encode_sint64_66000_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    ?assertEqual(
+        <<16#08, 16#A0, 16#87, 16#08>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 66000}, Schema))
+    ).
+
+encode_sint64_minus_66000_test() ->
+    Schema = #{
+        a => {1, sint64}
+    },
+    ?assertEqual(
+        <<16#08, 16#9F, 16#87, 16#08>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -66000}, Schema))
+    ).
+
+encode_fixed32_zero_test() ->
+    Schema = #{
+        a => {1, fixed32}
+    },
+    ?assertEqual(
+        <<16#0D, 16#00, 16#00, 16#00, 16#00>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 0}, Schema))
+    ).
+
+encode_fixed32_small_test() ->
+    Schema = #{
+        a => {1, fixed32}
+    },
+    ?assertEqual(
+        <<16#0D, 16#2A, 16#00, 16#00, 16#00>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 42}, Schema))
+    ).
+
+encode_fixed32_max_test() ->
+    Schema = #{
+        a => {1, fixed32}
+    },
+    ?assertEqual(
+        <<16#0D, 16#FF, 16#FF, 16#FF, 16#FF>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 4294967295}, Schema))
+    ).
+
+encode_fixed32_complex_test() ->
+    Schema = #{
+        a => {1, fixed32}
+    },
+    ?assertEqual(
+        <<16#0D, 16#EF, 16#BE, 16#AD, 16#DE>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 16#DEADBEEF}, Schema))
+    ).
+
+encode_fixed32_overflow_test() ->
+    Schema = #{
+        a => {1, fixed32}
+    },
+    ?assertError(badarg, aprotobuf_encoder:encode(#{a => 4294967296}, Schema)).
+
+encode_fixed32_underflow_test() ->
+    Schema = #{
+        a => {1, fixed32}
+    },
+    ?assertError(badarg, aprotobuf_encoder:encode(#{a => -1}, Schema)).
+
+encode_sfixed32_zero_test() ->
+    Schema = #{
+        a => {1, sfixed32}
+    },
+    ?assertEqual(
+        <<16#0D, 16#00, 16#00, 16#00, 16#00>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 0}, Schema))
+    ).
+
+encode_sfixed32_small_test() ->
+    Schema = #{
+        a => {1, sfixed32}
+    },
+    ?assertEqual(
+        <<16#0D, 16#2A, 16#00, 16#00, 16#00>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 42}, Schema))
+    ).
+
+encode_sfixed32_minus_one_test() ->
+    Schema = #{
+        a => {1, sfixed32}
+    },
+    ?assertEqual(
+        <<16#0D, 16#FF, 16#FF, 16#FF, 16#FF>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -1}, Schema))
+    ).
+
+encode_sfixed32_minus_42_test() ->
+    Schema = #{
+        a => {1, sfixed32}
+    },
+    ?assertEqual(
+        <<16#0D, 16#D6, 16#FF, 16#FF, 16#FF>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -42}, Schema))
+    ).
+
+encode_sfixed32_max_test() ->
+    Schema = #{
+        a => {1, sfixed32}
+    },
+    ?assertEqual(
+        <<16#0D, 16#FF, 16#FF, 16#FF, 16#7F>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 2147483647}, Schema))
+    ).
+
+encode_sfixed32_min_test() ->
+    Schema = #{
+        a => {1, sfixed32}
+    },
+    ?assertEqual(
+        <<16#0D, 16#00, 16#00, 16#00, 16#80>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -2147483648}, Schema))
+    ).
+
+encode_fixed64_zero_test() ->
+    Schema = #{
+        a => {1, fixed64}
+    },
+    ?assertEqual(
+        <<16#09, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 0}, Schema))
+    ).
+
+encode_fixed64_small_test() ->
+    Schema = #{
+        a => {1, fixed64}
+    },
+    ?assertEqual(
+        <<16#09, 16#2A, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 42}, Schema))
+    ).
+
+encode_fixed64_max_test() ->
+    Schema = #{
+        a => {1, fixed64}
+    },
+    ?assertEqual(
+        <<16#09, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 18446744073709551615}, Schema))
+    ).
+
+encode_fixed64_complex_test() ->
+    Schema = #{
+        a => {1, fixed64}
+    },
+    ?assertEqual(
+        <<16#09, 16#34, 16#12, 16#FE, 16#CA, 16#EF, 16#BE, 16#AD, 16#DE>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 16#DEADBEEFCAFE1234}, Schema))
+    ).
+
+encode_fixed64_overflow_test() ->
+    Schema = #{
+        a => {1, fixed64}
+    },
+    ?assertError(badarg, aprotobuf_encoder:encode(#{a => 18446744073709551616}, Schema)).
+
+encode_fixed64_underflow_test() ->
+    Schema = #{
+        a => {1, fixed64}
+    },
+    ?assertError(badarg, aprotobuf_encoder:encode(#{a => -1}, Schema)).
+
+encode_sfixed64_zero_test() ->
+    Schema = #{
+        a => {1, sfixed64}
+    },
+    ?assertEqual(
+        <<16#09, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 0}, Schema))
+    ).
+
+encode_sfixed64_small_test() ->
+    Schema = #{
+        a => {1, sfixed64}
+    },
+    ?assertEqual(
+        <<16#09, 16#2A, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 42}, Schema))
+    ).
+
+encode_sfixed64_minus_one_test() ->
+    Schema = #{
+        a => {1, sfixed64}
+    },
+    ?assertEqual(
+        <<16#09, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -1}, Schema))
+    ).
+
+encode_sfixed64_minus_42_test() ->
+    Schema = #{
+        a => {1, sfixed64}
+    },
+    ?assertEqual(
+        <<16#09, 16#D6, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -42}, Schema))
+    ).
+
+encode_sfixed64_max_test() ->
+    Schema = #{
+        a => {1, sfixed64}
+    },
+    ?assertEqual(
+        <<16#09, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#7F>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => 9223372036854775807}, Schema))
+    ).
+
+encode_sfixed64_min_test() ->
+    Schema = #{
+        a => {1, sfixed64}
+    },
+    ?assertEqual(
+        <<16#09, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00, 16#00, 16#80>>,
+        iolist_to_binary(aprotobuf_encoder:encode(#{a => -9223372036854775808}, Schema))
+    ).