Number to fixed-point notation without trailing zeros

Formats a number using fixed-point notation, if it has decimals.

• Use Number.prototype.toFixed() to convert the number to a fixed-point notation string.
• Use Number.parseFloat() to convert the fixed-point notation string to a number, removing trailing zeros.
• Use a template literal to convert the number to a string.

const toOptionalFixed = (num, digits) =>
  `${Number.parseFloat(num.toFixed(digits))}`;

toOptionalFixed(1, 2); // '1'
toOptionalFixed(1.001, 2); // '1'
toOptionalFixed(1.500, 2); // '1.5'