[Question] Lost units in JSON

[AlexandreRoba]

Hi all, Thanks for this amazing libraries.

I'm trying to serialize a length in JSON to store it in a JSON Document but I can seem to find the unit in the serialized object. Am I correct. Ths object seem to be serialized as
{"amount":12.5,"dimension":{"length":1}}

it serialize the same way no matter if its a km or a meter. Any advice on how to proceed? I do not want to loose the unit in the process.

Thanks.

[Lukinoh]

Hello,

I am not sure that the library was thought to have the quantity serializable.
As you mention the following quantities get serialized the same way:

const quantity1 = grams(1);
const quantity2 = kilograms(1);

// Result: {"amount":"1","dimension":{"mass":1}}

If you console.log the quantity1 and quantity2 you can see that the unit is stored in a function.
Hence the JSON.stringify strips it away.

QuantityImpl {
amount: 1,
unit: [Function: makeQuantity] UnitImpl {
  symbol: ' g',
  dimension: { mass: 1 },
  scale: 0.001,
  offset: 0,
  arithmetic: {
    from: [Function: from],
    toNative: [Function: toNative],
    add: [Function: add],
    sub: [Function: sub],
    mul: [Function: mul],
    div: [Function: div],
    pow: [Function: pow],
    abs: [Function: abs],
    compare: [Function: compare]
  }
},
dimension: { mass: 1 }
}

QuantityImpl {
amount: 1,
unit: [Function: makeQuantity] UnitImpl {
  symbol: ' kg',
  dimension: { mass: 1 },
  scale: 1,
  offset: 0,
  arithmetic: {
    from: [Function: from],
    toNative: [Function: toNative],
    add: [Function: add],
    sub: [Function: sub],
    mul: [Function: mul],
    div: [Function: div],
    pow: [Function: pow],
    abs: [Function: abs],
    compare: [Function: compare]
  }
},
dimension: { mass: 1 }
}

I don't know if the library will be update with a serialization feature.
Probably, the best solution you have without modifying the library is to write your own serializer.

The serialize function transform your quantity to:

{
  amount: number;
  symbol: string
}

And the deserialize calls the function that corresponds to the symbol with the amount.

// Trivial implementation
if (symbol === 'g') {
  return grams(amount)
} else if () {
}

[AlexandreRoba]

Hi @Lukinoh thanks for your reply, indeed I ended up with the same conclusion. I'm using trpc and superjson and some data cross the wire so I need to serialize it. Again for the library. I'm implementing my own serialization.