bpierre / dnum Goto Github PK

Thedn.format function currently always commifies numbers by default. It would be beneficial to have an option to turn this behavior off. This would provide greater flexibility in formatting number strings and improve the interoperability between dn.from and dn.format.

import * as dn from "dnum";

let b = dn.from("870983127.93887"); // dn.from() can parse strings, numbers, bigint and more

console.log(
  dn.format(b, 2), // Current behavior: "870,983,127.94"
  dn.format(b, { digits: 2, commify: false }), // Desired behavior: "870983127.94"
);

format([49998805n, 9], { digits: 4 } );
// return 0.05
// expected 0.0499

UX issue with normal rounding case:
The user use a little bit of gas token to do a transaction, but the displayed amount of balance still same because formatting is using normal round.

Change divideAndRound to floor div implementation will fix this.
What do you think?

const a = dn.from("5", 2);
dn.format(a, { digits: 2, trailingZeros: true })
// Expected 5.00
// Result 5

I was expecting number toFixed kinda behavior.
Shouldn't it also show trailing zero for consistency?
or is it intended?

const a = dn.from("5", 4);
const b = dn.from("5.1", 4);
const c = dn.from("5.12", 4);
const d = dn.from("5.123", 4);

console.log(dn.format(a, { digits: 4, trailingZeros: true })); // 5
console.log(dn.format(b, { digits: 4, trailingZeros: true })); // 5.1000
console.log(dn.format(c, { digits: 4, trailingZeros: true })); // 5.1200
console.log(dn.format(d, { digits: 4, trailingZeros: true })); // 5.1230

Can you export the Numberish type?
It's used in all the methods that you expose.

in the from method
String(value) converts expoents greater than 21 or less than -6 to scientific notation, which makes it not pass the regex in the next line

I was trying something like multiply(price, 10 ** -8, 18)
It's not a big issue since divide(price, 10 ** Math.abs(expo), 18) should do the same

a possible solution could be something like this, I'm not sure of the implications or if this should be handled in the lib, if you want I can look further and open a pr

  value = String(value);
  
  if (value.includes('e')) value = Number(value).toFixed(20)
  // or value = typeof value === 'number' ? value.toFixed(20) : String(value)

  if (!value.match(NUM_RE)) {
    throw new Error(`Incorrect number: ${value}`);
  }

It took some time today to figure what I was doing wrong here haha

Number.toString

Scientific notation is used if the radix is 10 and the number's magnitude (ignoring sign) is greater than or equal to 10^21 or less than 10-6

The type definitions in the build use relative import paths that don't include the extensions. This means projects using Node16 or NodeNext moduleResolution in their typescript projects won't be able to resolve the types.

• https://www.typescriptlang.org/docs/handbook/release-notes/typescript-4-7.html
• https://nodejs.org/api/esm.html#mandatory-file-extensions