super-utils-plus/dist/string/truncate.js

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"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.truncate = truncate;
/**
 * Truncates string if it's longer than the given maximum string length.
 * The last characters of the truncated string are replaced with the omission
 * string which defaults to "...".
 *
 * @param string - The string to truncate
 * @param options - The options object
 * @returns The truncated string
 *
 * @example
 * ```ts
 * truncate('hi-diddly-ho there, neighborino');
 * // => 'hi-diddly-ho there, neighbo...'
 *
 * truncate('hi-diddly-ho there, neighborino', {
 *   length: 24,
 *   omission: ' [...]'
 * });
 * // => 'hi-diddly-ho there [...]'
 *
 * truncate('hi-diddly-ho there, neighborino', {
 *   length: 24,
 *   omission: ' [...]',
 *   separator: ' '
 * });
 * // => 'hi-diddly-ho there [...]'
 *
 * truncate('hi-diddly-ho there, neighborino', {
 *   length: 24,
 *   omission: ' [...]',
 *   separator: /,? +/
 * });
 * // => 'hi-diddly-ho there [...]'
 * ```
 */
function truncate(string, options = {}) {
    if (!string) {
        return '';
    }
    const { length = 30, omission = '...', separator } = options;
    if (string.length <= length) {
        return string;
    }
    let truncateIndex = Math.max(0, length - omission.length);
    // If a separator is specified, find the last occurrence before the truncate index
    if (separator) {
        let lastIndex;
        if (typeof separator === 'string') {
            lastIndex = string.substring(0, truncateIndex).lastIndexOf(separator);
        }
        else {
            // Find the last match of the separator regex
            const matches = string.substring(0, truncateIndex).match(separator);
            lastIndex = matches && matches.length > 0
                ? string.substring(0, truncateIndex).lastIndexOf(matches[matches.length - 1]) +
                    matches[matches.length - 1].length
                : -1;
        }
        if (lastIndex >= 0) {
            truncateIndex = lastIndex;
        }
    }
    return string.substring(0, truncateIndex) + omission;
}