Angular 2+ truncate text pipe

truncatetext.pipe.ts

import { Pipe, PipeTransform } from '@angular/core';
/*
 * Truncates an text with defined cut off length
 * Takes an input parameter string.
 * Usage:
 *   string | truncatetext: 100
 * Example:
 *   <p>{{ string | truncatetext: 100 }}></p>
*/
@Pipe({
    name: 'truncatetext'
})
export class TruncateTextPipe implements PipeTransform {
    transform(value: string, length: number): string {
        const biggestWord = 50;
        const elipses = ' ...';

        if (typeof value === 'undefined') { return value; }
        if (value.length <= length) { return value; }

        // .. truncate to about correct lenght
        let truncatedText = value.slice(0, length + biggestWord);

        // .. now nibble ends till correct length
        while (truncatedText.length > length - elipses.length) {
            const lastSpace = truncatedText.lastIndexOf(' ');

            if (lastSpace === -1) { break; }

            truncatedText = truncatedText.slice(0, lastSpace).replace(/[!,.?;:]$/, '');
        }

        return truncatedText + elipses;
    }
}