Numeric

Sometimes you might find yourself in need of numeric string like extracting path parameter, but it's typed as string and need to be convert to number.

Using Elysia's transform life-cycle, you can manually parse number to string and re-use the transform function in other handler as well.

app.get("/id/:id", ({ params: { id } }) => id, {
  params: t.Object({
    id: t.Number(),
  }),
  transform({ params }) {
    const id = +params.id;

    if (!Number.isNaN(id)) params.id = id;
  },
});

However, it's a little bit redundant and requires boilerplate, so Elysia has a custom type to speed up the situation with t.Numeric

app.get("/id/:id", ({ params: { id } }) => id, {
  params: t.Object({
    id: t.Numeric(),
  }),
});

This allows us to convert a valid numeric string to a number automatically.

If the string is not a valid numeric string, it will throw an error in the runtime and prevent execution inside the handler.

You can use the numeric type on any property that supports schema typing, including:

params
query
headers
body
response

Numeric#

Numeric