solana/explorer/src/utils/index.tsx

import React from "react";
import { LAMPORTS_PER_SOL } from "@solana/web3.js";
import {
  HumanizeDuration,
  HumanizeDurationLanguage,
} from "humanize-duration-ts";
import { ReactNode } from "react";

export const NUM_TICKS_PER_SECOND = 160;
export const DEFAULT_TICKS_PER_SLOT = 64;
export const NUM_SLOTS_PER_SECOND =
  NUM_TICKS_PER_SECOND / DEFAULT_TICKS_PER_SLOT;
export const MS_PER_SLOT = 1000 / NUM_SLOTS_PER_SECOND;

export function assertUnreachable(x: never): never {
  throw new Error("Unreachable!");
}

export function lamportsToSolString(
  lamports: number,
  maximumFractionDigits: number = 9
): ReactNode {
  const sol = Math.abs(lamports) / LAMPORTS_PER_SOL;
  return (
    <>
      ◎
      <span className="text-monospace">
        {new Intl.NumberFormat("en-US", { maximumFractionDigits }).format(sol)}
      </span>
    </>
  );
}

const HUMANIZER = new HumanizeDuration(new HumanizeDurationLanguage());
HUMANIZER.setOptions({
  language: "short",
  spacer: "",
  delimiter: " ",
  round: true,
  units: ["d", "h", "m", "s"],
  largest: 3,
});
HUMANIZER.addLanguage("short", {
  y: () => "y",
  mo: () => "mo",
  w: () => "w",
  d: () => "d",
  h: () => "h",
  m: () => "m",
  s: () => "s",
  ms: () => "ms",
  decimal: ".",
});

export function slotsToHumanString(slots: number): string {
  return HUMANIZER.humanize(slots * MS_PER_SLOT);
}