Number as String Package

This package provides precise number scaling and formatting without the common floating-point precision issues found in JavaScript.

Why Use This Package?

JavaScript's native handling of floating-point arithmetic can lead to unexpected results, especially with large or small numbers. number-as-string ensures precise number manipulation without these issues.

Common JavaScript Errors

To illustrate why this package is useful, here are some common JavaScript floating-point issues:

• Multiplication with Small Numbers:

  console.log(0.000000001 * 10 ** 18); // Expected: 1000000000., Result: 1000000000.0000001

• Using toFixed:

  console.log((0.2161).toFixed(18)); // Expected: '0.216100000000000000', Result: '0.216099999999999987'

• Division of Large Numbers:

  console.log(100000000000000000000000 / 10 ** 18); // Expected: 100000, Result: 99999.99999999999

number-as-string solves these issues elegantly.

Key capabilities include:

• scaleUp: Converts a number as a string into a larger scaled format, preserving precision.
• scaleDown: Converts a scaled number back to its original format with precision.
• trimWithPrecision: Trims a number string to a specified decimal precision without unexpected rounding errors.

Installation

To install the package, run:

npm install number-as-string

Usage

Import the required functions from the package:

const { scaleUp, scaleDown, trimWithPrecision } = require("number-as-string");

Examples

• Scaling Up:

  scaleUp("0.000000001", 18); // Returns '1000000000'
  scaleUp("1.23", 3); // Returns '1230'

• Scaling Down:

  scaleDown("1000000000", 18); // Returns '0.000000001'
  scaleDown("1230", 3); // Returns '1.23'

• Trimming with Precision:

  trimWithPrecision("0.2161", 18); // Returns '0.2161'
  trimWithPrecision("1234567890.987654321", 5); // Returns '1234567890.98765'

Tested Cases

The following cases have been tested to ensure precision:

• Large number scaling:

  scaleUp("9876543210.123456789", 9); // Returns '9876543210123456789'
  scaleDown("9876543210123456789", 9); // Returns '9876543210.123456789'

• Small number scaling:

  scaleUp("0.00000000123456789", 18); // Returns '1234567890'
  scaleDown("1234567890", 18); // Returns '0.00000000123456789'

• Scientific notation scaling:

  scaleDown("1.2e3", 2); // Returns '12'
  scaleDown("1.2e-3", 5); // Returns '0.000000012'
  scaleDown(1.23e18, 18); // Returns '1.23'
  scaleDown(1.234e18, 18); // Returns '1.234'
  scaleUp("1.2e-3", 5); // Returns '120'
  scaleUp("1.245576e-3", 5); // Returns '124'
  scaleUp("1.23e4", 2); // Returns '1230000'
  scaleUp("1e-18", 20); // Returns '100'

• Mixed precision trimming:

  trimWithPrecision("0.00000000123456789", 10); // Returns '0.0000000012'
  trimWithPrecision("0.2161", 18); // Returns '0.2161'
  trimWithPrecision("1", 18); // Returns '1'

• Trimming scientific notation numbers:

  trimWithPrecision(1e3, 0); // Returns '1000'
  trimWithPrecision("1e18", 0); // Returns '1' + '0'.repeat(18)
  trimWithPrecision("1E3", 1); // Returns '1000'
  trimWithPrecision("-1e3", 2); // Returns '-1000'

• Extreme edge cases:

  scaleUp("0", 18); // Returns '0'
  scaleDown("0", 18); // Returns '0'
  scaleUp("1", 0); // Returns '1'
  scaleDown("1", 0); // Returns '1'
  trimWithPrecision("1.9999999999999999", 18); // Returns '1.9999999999999999'
  trimWithPrecision("0.0000000000000001", 18); // Returns '0.0000000000000001'

Contributing

Contributions are welcome! Please open an issue or submit a pull request with any improvements.

License

This project is licensed under the MIT License.