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'use strict';
const sliceAnsi = require('slice-ansi');
const stringWidth = require('string-width');
function getIndexOfNearestSpace(string, index, shouldSearchRight) {
if (string.charAt(index) === ' ') {
return index;
}
for (let i = 1; i <= 3; i++) {
if (shouldSearchRight) {
if (string.charAt(index + i) === ' ') {
return index + i;
}
} else if (string.charAt(index - i) === ' ') {
return index - i;
}
}
return index;
}
module.exports = (text, columns, options) => {
options = {
position: 'end',
preferTruncationOnSpace: false,
...options
};
const {position, space, preferTruncationOnSpace} = options;
let ellipsis = '…';
let ellipsisWidth = 1;
if (typeof text !== 'string') {
throw new TypeError(`Expected \`input\` to be a string, got ${typeof text}`);
}
if (typeof columns !== 'number') {
throw new TypeError(`Expected \`columns\` to be a number, got ${typeof columns}`);
}
if (columns < 1) {
return '';
}
if (columns === 1) {
return ellipsis;
}
const length = stringWidth(text);
if (length <= columns) {
return text;
}
if (position === 'start') {
if (preferTruncationOnSpace) {
const nearestSpace = getIndexOfNearestSpace(text, length - columns + 1, true);
return ellipsis + sliceAnsi(text, nearestSpace, length).trim();
}
if (space === true) {
ellipsis += ' ';
ellipsisWidth = 2;
}
return ellipsis + sliceAnsi(text, length - columns + ellipsisWidth, length);
}
if (position === 'middle') {
if (space === true) {
ellipsis = ' ' + ellipsis + ' ';
ellipsisWidth = 3;
}
const half = Math.floor(columns / 2);
if (preferTruncationOnSpace) {
const spaceNearFirstBreakPoint = getIndexOfNearestSpace(text, half);
const spaceNearSecondBreakPoint = getIndexOfNearestSpace(text, length - (columns - half) + 1, true);
return sliceAnsi(text, 0, spaceNearFirstBreakPoint) + ellipsis + sliceAnsi(text, spaceNearSecondBreakPoint, length).trim();
}
return (
sliceAnsi(text, 0, half) +
ellipsis +
sliceAnsi(text, length - (columns - half) + ellipsisWidth, length)
);
}
if (position === 'end') {
if (preferTruncationOnSpace) {
const nearestSpace = getIndexOfNearestSpace(text, columns - 1);
return sliceAnsi(text, 0, nearestSpace) + ellipsis;
}
if (space === true) {
ellipsis = ' ' + ellipsis;
ellipsisWidth = 2;
}
return sliceAnsi(text, 0, columns - ellipsisWidth) + ellipsis;
}
throw new Error(`Expected \`options.position\` to be either \`start\`, \`middle\` or \`end\`, got ${position}`);
};
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