Add option to prefer text unmarshaler when data type is String #371
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This library currently always prefers to use encoding.BinaryUnmashaler when it's implemented by the target type. This might lead to problems when the type also has a text representation implemented as encoding.TextUnmarshaler. Consider netip.Addr from stdlib as example, which implements both. This library won't be able decode MessagePack containing a string "192.0.2.1" into *netip.Addr because it will attempt to use encoding.BinaryUnmashaler which doesn't expect text representation. Fortunately, MessagePack has distinct string and binary types, so we can check the source data type before choosing the interface to use. This commit changes the behaviour of decoder as follows. When 1) target Go data type implements both BinaryUnmashaler and TextUnmarshaler 2) source MessagePack data type is a string TextUnmarshaler will be preferred over BinaryUnmashaler. This feature is gated behind a Decoder option, because it is potentially backward-incompatible change. See vmihailenco#370
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This library currently always prefers to use
encoding.BinaryUnmashalerwhen it's implemented by the target type.This might lead to problems when the type also has a text representation implemented as
encoding.TextUnmarshaler.Consider
netip.Addrfrom stdlib as example, which implements both. This library won't be able decode MessagePack containing a string"192.0.2.1"into*netip.Addrbecause it will attempt to useencoding.BinaryUnmashalerwhich doesn't expect text representation.Fortunately, MessagePack has distinct string and binary types, so we can check the source data type before choosing the interface to use.
This commit changes the behaviour of decoder as follows. When
BinaryUnmashalerandTextUnmarshalerTextUnmarshalerwill be preferred overBinaryUnmashaler.This feature is gated behind a
Decoderoption, because it is potentially backward-incompatible change.See #370