etcher/lib/gui/app/utils/middle-ellipsis.js
Alexis Svinartchouk fe230e7d30 Rename resin -> balena
Change-type: patch
2019-12-12 18:25:54 +01:00

69 lines
2.1 KiB
JavaScript

/*
* Copyright 2016 Juan Cruz Viotti. https://github.com/jviotti
* Copyright 2018 balena.io
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
'use strict'
/**
* @summary Truncate text from the middle with an ellipsis
* @public
* @function
*
* @param {String} input - input string
* @param {Number} limit - output limit
* @returns {String} truncated string
*
* @throws Will throw if `limit` < 3
*
* @example
* middleEllipsis('MyVeryLongString', 5)
* > 'My\u2026ng'
*/
module.exports = (input, limit) => {
const MIDDLE_ELLIPSIS_CHARACTER = '\u2026'
const MINIMUM_LENGTH = 3
// We can't provide a 100% expected result if the limit is less than 3. For example:
//
// If the limit == 2:
// Should we display the first at last character without an ellipses in the middle?
// Should we display just one character and an ellipses before or after?
// Should we display nothing at all?
//
// If the limit == 1:
// Should we display just one character?
// Should we display just an ellipses?
// Should we display nothing at all?
//
// Etc.
if (limit < MINIMUM_LENGTH) {
throw new Error('middleEllipsis: Limit should be at least 3')
}
// Do nothing, the string doesn't need truncation.
if (input.length <= limit) {
return input
}
/* eslint-disable no-magic-numbers */
const lengthOfTheSidesAfterTruncation = Math.floor((limit - 1) / 2)
const finalLeftPart = input.slice(0, lengthOfTheSidesAfterTruncation)
const finalRightPart = input.slice(input.length - lengthOfTheSidesAfterTruncation)
/* eslint-enable no-magic-numbers */
return finalLeftPart + MIDDLE_ELLIPSIS_CHARACTER + finalRightPart
}