codec-protobuf
There's an associated @dxos/protobuf-compiler package that does codegen based on protobuf schema.
Handling of scalar fields with default values
Based on:
- https://github.com/protocolbuffers/protobuf/blob/main/docs/field_presence.md
- https://github.com/protocolbuffers/protobuf/blob/main/docs/implementing_proto3_presence.md
In protobuf scalar fields (numbers, booleans, strings, bytes, enums) may have an implicit default value:
- 0 for number types
- false for booleans
- '' (empty string) for strings
- [] for bytes
- First enum value for enums
Non-optional fields
Example:
int32 number = 1;If the field is set to it's default value (0 in this example) it MAY be missing in the wire encoding (Go implementation) or present with the value set to 0 (JS implementation).
When decoding, the missing fields MUST be treated as having the default implicit value (0 in this case).
Optional fields
optional int32 number = 1;If the field is set to it's default value (0 in this example) it MUST be present in the wire encoding with the value set to 0.
When decoding, the missing fields it MUST be set as undefined. If the field is present in the wire format, it must be set to its numeric value.
Toolchain
This package must NOT use toolchain to avoid cyclic dependencies.