toJSON does not emit canonical JSON for non-finite double/float values, breaking round-trips through JSON.stringify

[jeffw-wherethebitsroam]

Using version: 2.11.8

We make use of +-Infinity in our protobuf messages. When using toJSON and JSON.stringify, these values get lost.

syntax = "proto3";
message Msg {
  double min = 1;
}

  const msg = Msg.create({ min: -Infinity })

  const obj = Msg.toJSON(msg)
  // obj => { min: -Infinity }   (raw JS number, not the canonical string)

  const wire = JSON.stringify(obj)
  // wire => '{"min":null}'      (JSON.stringify turns Infinity/NaN into null)

  const back = Msg.fromJSON(JSON.parse(wire))
  // back => { min: 0 }          (value lost)

From the spec it looks like these should be converted to strings and these appear to work with fromJSON if I use a replacer:

function nonFiniteReplacer(_key: string, value: unknown): unknown {
  if (typeof value === 'number' && !Number.isFinite(value)) {
    if (value === Infinity) return 'Infinity'
    if (value === -Infinity) return '-Infinity'
    return 'NaN'
  }
  return value
}

const wire = JSON.stringify(Msg.toJSON(msg), nonFiniteReplacer)
// wire => '{"min":"-Infinity"}'

const back = Msg.fromJSON(JSON.parse(wire))
  // back => { min: -Infinity }

But now I need to track this everywhere! toJSON should convert these to strings to be compatible with cannoncial json.

[jeffw-wherethebitsroam]

Spec reference: https://protobuf.dev/programming-guides/json/#field-representation