Circle Calculations

A JavaScript library for calculating circle properties from a single input.

Supported inputs:

• radius
• diameter
• perimeter
• area

The library always returns a complete result object with:

• radius
• diameter
• perimeter
• area

Installation

npm install

Usage

const {
  calculateCircle,
  fromRadius,
  fromDiameter,
  fromPerimeter,
  fromArea,
} = require('./src/circle');

1) Universal function

calculateCircle(input) expects an object with exactly one property:

• { radius: number }
• { diameter: number }
• { perimeter: number }
• { area: number }

Example:

const result = calculateCircle({ radius: 5 });

console.log(result);
// {
//   radius: 5,
//   diameter: 10,
//   perimeter: 31.41592653589793,
//   area: 78.53981633974483
// }

2) Specialized functions

• fromRadius(radius)
• fromDiameter(diameter)
• fromPerimeter(perimeter)
• fromArea(area)

Example:

const a = fromDiameter(10);
const b = fromArea(Math.PI);

API

calculateCircle(input)

Input:

• input: { radius?: number, diameter?: number, perimeter?: number, area?: number }

Rules:

• The object must contain exactly one supported property.
• The value must be a positive finite number (> 0).

Output:

{
  radius: number;
  diameter: number;
  perimeter: number;
  area: number;
}

fromRadius(radius)

Calculates all circle values from a radius.

fromDiameter(diameter)

Calculates all circle values from a diameter.

fromPerimeter(perimeter)

Calculates all circle values from a perimeter.

fromArea(area)

Calculates all circle values from an area.

Validation and errors

The library throws TypeError when:

• input is not an object (for example: null, array)
• 0 or more than 1 supported property is provided
• value is not a number, is NaN, Infinity, or <= 0

Example:

calculateCircle({}); // TypeError
calculateCircle({ radius: 2, area: 5 }); // TypeError
fromRadius(0); // TypeError

Tests

Run tests:

npm test

Test coverage includes:

• calculations from all supported input types
• consistency of output values
• validation errors

Publishing to npm

This project includes a publish script:

npm run publish:npm -- --tag latest --access public

Options:

• --tag <tag> (default: latest)
• --access <public|restricted> (default: public)
• --dry-run for a publish simulation

Examples:

npm run publish:npm -- --dry-run
npm run publish:npm -- --tag next

What the script does:

• runs tests
• verifies npm login (npm whoami)
• builds a package tarball (npm pack)
• publishes with npm publish