GT2/Ejectable/node_modules/react-native/Libraries/Utilities/truncate.js

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2021-08-16 00:14:59 +00:00
/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @format
* @flow
*/
'use strict';
type truncateOptions = {
breakOnWords: boolean,
minDelta: number,
elipsis: string,
...
};
const defaultOptions = {
breakOnWords: true,
minDelta: 10, // Prevents truncating a tiny bit off the end
elipsis: '...',
};
// maxChars (including ellipsis)
const truncate = function(
str: ?string,
maxChars: number,
options?: truncateOptions,
): ?string {
options = Object.assign({}, defaultOptions, options);
if (
str &&
str.length &&
str.length - options.minDelta + options.elipsis.length >= maxChars
) {
// If the slice is happening in the middle of a wide char, add one more char
const extraChar =
str.charCodeAt(maxChars - options.elipsis.length) > 255 ? 1 : 0;
str = str.slice(0, maxChars - options.elipsis.length + 1 + extraChar);
if (options.breakOnWords) {
const ii = Math.max(str.lastIndexOf(' '), str.lastIndexOf('\n'));
str = str.slice(0, ii);
}
str = str.trim() + options.elipsis;
}
return str;
};
module.exports = truncate;