TDD Utility Library

A utility function library developed using TDD (Test-Driven Development). Provides various features including mathematical operations, data validation, and formatting.

Installation

``bash
npm install @skybaer0804/tdd
`

or

`bash
yarn add @skybaer0804/tdd
`

Usage

`javascript
// Method 1: Import all functions at once
import { add, subtract, pow, divide, percent, isNum, isPositiveNum, isUrl, isInputXssSafe, toNum, toStringComma, toRenderXssSafe } from '@skybaer0804/tdd';

// Method 2: Import by category
import { add, subtract, pow, divide, percent } from '@skybaer0804/tdd/math';
import { isNum, isPositiveNum, isUrl, isInputXssSafe } from '@skybaer0804/tdd/validate';
import { toNum, toStringComma, toRenderXssSafe } from '@skybaer0804/tdd/format';

// Math functions
console.log(add(2, 3)); // 5
console.log(add('1', '2')); // 3
console.log(subtract(5, 3)); // 2
console.log(pow(2, 3)); // 8
console.log(divide(10, 2)); // 5
console.log(percent(50, 100)); // 50

// Validation functions
console.log(isNum(123)); // true
console.log(isUrl('https://example.com')); // true
console.log(isInputXssSafe('')); // false

// Format functions
console.log(toNum('123')); // 123
console.log(toStringComma(1234)); // '1,234'
console.log(toRenderXssSafe('')); // '<script>alert(1)</script>'
`

API Documentation

$3

#### add(a, b)

Adds two numbers. Automatically converts string numbers.

- a (number|string): First number
- b (number|string): Second number
- Returns: (number) Sum of two numbers

`javascript
add(2, 3); // 5
add('1', '2'); // 3
add('1,000', '2,000'); // 3000
`

#### subtract(a, b)

Subtracts two numbers. Automatically converts string numbers.

- a (number|string): First number
- b (number|string): Second number
- Returns: (number) Difference of two numbers

`javascript
subtract(5, 3); // 2
subtract('5', '3'); // 2
`

#### pow(base, exponent)

Power function. Automatically converts string numbers.

- base (number|string): Base
- exponent (number|string): Exponent
- Returns: (number) Base raised to the power of exponent

`javascript
pow(2, 3); // 8
pow('2', '3'); // 8
`

#### divide(dividend, divisor)

Division function. Automatically converts string numbers.

- dividend (number|string): Number to be divided
- divisor (number|string): Number to divide by
- Returns: (number) Result of division

`javascript
divide(10, 2); // 5
divide('10', '2'); // 5
`

#### percent(value, total)

Calculates percentage.

- value (number|string): Value to calculate
- total (number|string): Total value
- Returns: (number) Percentage

`javascript
percent(50, 100); // 50
percent(25, 100); // 25
percent(1, 3); // 33.333...
`

$3

#### isNum(value)

Checks if a value is a number.

- value (\*): Value to check
- Returns: (boolean) true if number, false otherwise

`javascript
isNum(123); // true
isNum('123'); // false
isNum(null); // false
`

#### isPositiveNum(value)

Checks if a value is a non-negative integer.

- value (\*): Value to check
- Returns: (boolean) true if non-negative integer, false otherwise

`javascript
isPositiveNum(0); // true
isPositiveNum(1); // true
isPositiveNum(-1); // false
`

#### isUrl(value)

Checks if a value is a valid URL format.

- value (\*): Value to check
- Returns: (boolean) true if valid URL, false otherwise

`javascript
isUrl('https://example.com'); // true
isUrl('not-a-url'); // false
`

#### isInputXssSafe(value)

Checks if input value is safe from XSS attacks.

- value (\*): Value to check
- Returns: (boolean) true if safe, false if dangerous

`javascript
isInputXssSafe('Safe text'); // true
isInputXssSafe(''); // false
`

$3

#### toNum(value)

Converts a value to a number.

- value (\*): Value to convert
- Returns: (number) Converted number

`javascript
toNum('123'); // 123
toNum(' 12,340 '); // 12340
toNum('abc'); // NaN
`

#### toStringComma(value)

Converts a number to a string with thousand separators.

- value (number|string): Number or string to convert
- Returns: (string) String with commas

`javascript
toStringComma(1234); // '1,234'
toStringComma(1234567); // '1,234,567'
`

#### toRenderXssSafe(value)

Escapes HTML special characters to prevent XSS attacks.

- value (\*): Value to escape
- Returns: (string) Escaped safe string

`javascript
toRenderXssSafe('Safe text'); // 'Safe text'
toRenderXssSafe(''); // '<script>alert("XSS")</script>'
`

Running Tests

`bash
npm test
``

Development

This project follows the TDD Red-Green-Blue cycle:

1. Red Phase: Write failing test code
2. Green Phase: Write minimal code to pass tests
3. Blue Phase: Refactor and clean up code

Changelog

$3

#### New Features

- Added format category (toNum, toStringComma, toRenderXssSafe)
- Extended validate category (isUrl, isInputXssSafe)
- Extended math category (percent)

#### Improvements

- Improved non-number input handling in math functions
- Support for automatic string number conversion
- Support for string numbers with spaces and commas

$3

- Initial version
- Basic math functions (add, subtract, pow, divide)
- Basic validation functions (isNum, isPositiveNum)

License

MIT