What is the typical way to persist currency?

[johnhooks]

Dinero.js tracks those amendments and updates currencies accordingly. Such changes are, by definition, breaking. To preserve fixed versioning, the library's entry point doesn't export updated currencies. In other words, if you import currencies from the path @dinero.js/currencies, they won't change.

Using Built In Currencies

I understand that I can rely on the currencies not to change, unless upgrading to a breaking change version of dinero. But what is the typical way to persist the currency of a dinero object, like in a database, so it can be retrieved later and also insured that the appropriate currency exponent and base always be used?

Should the whole snapshot of the dinero object be persisted, with its currency, to ensure its value is always interpreted correctly?

CREATE TABLE "ExampleAmount" (
    "amount" INTEGER,
    "code" VARCHAR(3);
    "base" INTEGER,
    "exponent" INTEGER,
    "scale" INTEGER
);

I get that all applications will have different needs, but I just want to make sure I am on the right track, and not over thinking it.

[sarahdayan]

Hey @johnhooks!

I understand that I can rely on the currencies not to change, unless upgrading to a breaking change version of dinero.

What the documentation means is that, if a currency changes (for example, if the U.S. dollar suddenly becomes 1000 cents in a dollar), changing it in Dinero.js is a breaking change in nature, which is why there's a different importing strategy to avoid breakages.

But what is the typical way to persist the currency of a dinero object, like in a database, so it can be retrieved later and also insured that the appropriate currency exponent and base always be used?

There's a whole guide on this topic. It's good practice to store a full snapshot of Dinero objects in database, which is why the API exposes a toSnapshot function.

[johnhooks]

Thank you for the validation that I wasn't misunderstanding.

In the example, Serializing an object, does a Dinero object have a toString method that uses toSnapshot? Or does the fetch call have a bug?

fetch('http://example.org/api/products', {
  method: 'POST',
  body: JSON.stringify(product),
});

Should it be above, as in the example, or the snippet below?

fetch('http://example.org/api/products', {
  method: 'POST',
  body: JSON.stringify(toSnapshot(product)),
});

Its also the same in Handling arbitrary precision amounts. Both examples import toSnapshot but don't use it.

[johnhooks]

I read the documentation for JSON.stringify. I found out it will call the toJSON method on a dinero object, and toSnapshot also does the same thing.

[sarahdayan]

Yep, the import in the docs is unused.