ramda-adjunct/src/isNegative.js

Ramda Adjunct is the most popular and most comprehensive set of utilities for use with Ramda, providing a variety of useful, well tested functions with excellent documentation.

import { both, gt } from 'ramda';
import curry1 from 'ramda/src/internal/_curry1';

import isNumber from './isNumber';

/**
 * Checks if value is a negative `Number` primitive or object. Zero is not considered neither
 * positive or negative.
 *
 * @func isNegative
 * @memberOf RA
 * @since {@link https://char0n.github.io/ramda-adjunct/1.15.0|v1.15.0}
 * @category Type
 * @sig * -> Boolean
 * @param {*} val The value to test
 * @return {boolean}
 * @see {@link RA.isPositive|isPositive}
 * @example
 *
 * RA.isNegative(-1); // => true
 * RA.isNegative(Number.MIN_VALUE); // => false
 * RA.isNegative(+Infinity); // => false
 * RA.isNegative(NaN); // => false
 * RA.isNegative('5'); // => false
 */
const isNegative = curry1(both(isNumber, gt(0)));

export default isNegative;