@woosh/meep-engine/src/core/primitives/numbers/number_pretty_print.js

Pure JavaScript game engine. Fully featured and production ready.

import { assert } from "../../assert.js";
import { string_strip_trailing } from "../strings/string_strip_trailing.js";
import { number_format_by_thousands } from "./number_format_by_thousands.js";

/**
 *
 * @param {number} value
 * @returns {string}
 */
export function number_pretty_print(value) {
    assert.isNumber(value, 'value');

    const MAX_DECIMALS = 2;

    const fraction = value % 1;

    const would_produce_decimals = fraction * Math.pow(10, MAX_DECIMALS) > 0;

    if (would_produce_decimals && Math.abs(value) < 100) {
        const truncated = value.toFixed(MAX_DECIMALS);
        return string_strip_trailing(truncated, "0");
    } else {
        //no fraction
        return number_format_by_thousands(value - fraction, ",");
    }

}