73 lines
3.2 KiB
JavaScript
73 lines
3.2 KiB
JavaScript
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import { isObject } from "../predicate/isObject.mjs";
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//#region src/compat/string/truncate.ts
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/**
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* Used to compose unicode character classes.
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* @link https://github.com/lodash/lodash/blob/4.17.21-es/_hasUnicode.js
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*
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* Used to detect strings with zero-width joiners or code points from the astral planes.
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* @link http://eev.ee/blog/2015/09/12/dark-corners-of-unicode/
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*/
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const regexMultiByte = /[\u200d\ud800-\udfff\u0300-\u036f\ufe20-\ufe2f\u20d0-\u20ff\ufe0e\ufe0f]/;
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/**
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* This regex might more completely detect unicode, but it is slower and this project
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* desires to mimic the behavior of lodash.
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*/
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/**
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* Truncates `string` if it's longer than the given maximum string length.
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* The last characters of the truncated string are replaced with the omission
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* string which defaults to "...".
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*
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* @param {string} [string=''] The string to truncate.
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* @param {Object} [options={}] The options object.
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* @param {number} [options.length=30] The maximum string length.
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* @param {string} [options.omission='...'] The string to indicate text is omitted.
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* @param {RegExp|string} [options.separator] The separator pattern to truncate to.
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*
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* @example
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* const test = 'hi-diddly-ho there, neighborino';
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* const truncatedStr1 = truncate(test) // returns 'hi-diddly-ho there, neighbo...'
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* const truncatedStr2 = truncate(test, { length: 24, separator: ' ' }) // returns 'hi-diddly-ho there,...'
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* const truncatedStr3 = truncate(test, { length: 24, separator: /,? +/ }) // returns 'hi-diddly-ho there...'
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* const truncatedStr4 = truncate(test, { omission: ' [...]' }) // returns 'hi-diddly-ho there, neig [...]'
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* const truncatedStr5 = truncate('ABC', { length: 3 }) // returns 'ABC'
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* const truncatedStr6 = truncate('ABC', { length: 2 }) // returns '...'
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* const truncatedStr7 = truncate('¥§✈✉🤓', { length: 5 }) // returns '¥§✈✉🤓'
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* const truncatedStr8 = truncate('¥§✈✉🤓', { length: 4, omission: '…' }) // returns '¥§✈…'
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*/
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function truncate(string, options) {
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string = string != null ? `${string}` : "";
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let length = 30;
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let omission = "...";
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if (isObject(options)) {
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length = parseLength(options.length);
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omission = "omission" in options ? `${options.omission}` : "...";
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}
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let i = string.length;
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const lengthOmission = Array.from(omission).length;
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const lengthBase = Math.max(length - lengthOmission, 0);
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let strArray = void 0;
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if (regexMultiByte.test(string)) {
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strArray = Array.from(string);
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i = strArray.length;
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}
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if (length >= i) return string;
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if (i <= lengthOmission) return omission;
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let base = strArray === void 0 ? string.slice(0, lengthBase) : strArray?.slice(0, lengthBase).join("");
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const separator = options?.separator;
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if (!separator) {
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base += omission;
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return base;
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}
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const search = separator instanceof RegExp ? separator.source : separator;
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const flags = "u" + (separator instanceof RegExp ? separator.flags.replace("u", "") : "");
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const withoutSeparator = new RegExp(`(?<result>.*(?:(?!${search}).))(?:${search})`, flags).exec(base);
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return (!withoutSeparator?.groups ? base : withoutSeparator.groups.result) + omission;
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}
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function parseLength(length) {
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if (length == null) return 30;
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if (length <= 0) return 0;
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return length;
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}
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//#endregion
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export { truncate };
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