@fiquu/shorten/lib/index.js

Shortens a string (truncate) optionally keeping whole words.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
/**
 * Shorten default options.
 */
const defaults = Object.freeze({
    ellipsis: '...',
    words: true,
    length: 50,
    lax: false
});
/**
 * Trims a string to the provided length.
 *
 * @param {string} value The value to trim.
 * @param {number} length The maximum string length.
 * @param {string} ellipsis The ellipsis string to use.
 * @param {boolean} lax Whether to not include ellipsis length on the maximum length.
 *
 * @returns {string} The trimmed string.
 */
const trimToLength = (value, length, ellipsis, lax) => {
    const pad = lax ? 0 : ellipsis.length;
    return value.substr(0, length - pad);
};
/**
 * Trims a string to words.
 *
 * @param {string} value The value to trim.
 * @param {string} ellipsis The ellipsis string to use.
 *
 * @returns {string} The trimmed string.
 */
const trimToWords = (value, ellipsis) => {
    const lastSpace = value.lastIndexOf(' ');
    const index = Math.min(value.length, lastSpace);
    const adjusted = value.substr(0, index);
    return `${adjusted}${ellipsis}`;
};
/**
 * Shortens (truncates) a string to a max length keeping whole words by default.
 *
 * @param {string} value The string to shorten.
 * @param {object} options The options object.
 * @param {number} options.length Maximum length to return. Defaults to `50`.
 * @param {string} options.ellipsis Ellipsis string to use. Defaults to `'...'`.
 * @param {boolean} options.words Whether to keep words. Defaults to `true`.
 * @param {boolean} options.lax Whether to not include the ellipsis length in the maximum length. Defaults to `false`.
 *
 * @example
 * // Returns 'The...'
 * shorten('The strnig is logn and full of erorrs.');
 * @example
 * // Returns 'The strnig is...'
 * shorten('The strnig is logn and full of erorrs.', { length: 20 });
 *
 * @returns {string} The shortened (truncated) string.
 */
const shorten = (value, options) => {
    const { length, ellipsis, words, lax } = {
        ...defaults,
        ...options
    };
    if (!value) {
        return '';
    }
    if (value.length <= length) {
        return value;
    }
    const trimmed = trimToLength(value, length, ellipsis, lax);
    if (words) {
        return trimToWords(trimmed, ellipsis);
    }
    return `${trimmed}${ellipsis}`;
};
exports.default = shorten;