serializerCodec

serializerCodec<T>(serializer, name?): Codec<T>

Defined in: src/persistence/migration/Codec.ts:166

Adapt a byte-native Serializer into a Codec<T> (#73), so a binary format reaches the migration layer at the granularity the migration layer actually works at.

Why this exists next to withSerializer. A store’s serializer option applies to the whole store — one format for every payload it writes. The SchemaRegistry holds a codec per (manifest, version), which is the only place a v1 written in Avro and a v2 written in Protobuf can coexist in one stream. Wrapping the serializer keeps a single implementation of each format instead of one Serializer plus a near-identical Codec:

registry.register('BankAccount.Deposited', 1, {
  codec: serializerCodec(avroSerializer),
});
registry.register('BankAccount.Deposited', 2, {
  codec: serializerCodec(protobufSerializer),
  upcastFromPrev: (v1: DepositedV1): DepositedV2 => ({ ...v1, currency: 'USD' }),
});

Wire shape. encode returns a SerializedValue — {serializerId, manifest, bytes} — and stops there. The bytes are NOT base64’d here: the journal’s PayloadCodec already round-trips a Uint8Array through the tagged-JSON __bytes__ form, so encoding them again would cost a second base64 expansion for nothing. serializerId travels with the payload so a row written by one serializer and read back by another fails with a named error instead of decoding into garbage — Avro in particular carries no field tags, so wrong bytes decode “successfully”.

Type Parameters

T

T

Parameters

serializer

Serializer<T>

name?

string

Returns

Codec<T>