Angular 2+ reading time pipe

readingtime.pipe.ts

import { Pipe, PipeTransform } from '@angular/core';
/*
 * Show total reading time for an text
 * Takes an input parameter text.
 * Usage:
 *   value | readingtime
 * Example:
 *   {{ This is a content of my blog post | readingtime }} min read.
 *   formats to: 1 min read.
*/
@Pipe({
    name: 'readingtime'
})
export class ReadingTimePipe implements PipeTransform {
    transform(value: string) {
        let readingTimeMinutes = 1;

        if (value !== '') {
            // split text by spaces to define total words
            const totalWords = value.trim().split(/\s+/g).length;

            // define words per second based on words per minute (s.wordsPerMinute)
            // Read time is based on the average reading speed of an adult (roughly 265 WPM, Medium.com)
            // Wikipedia suggests a proofreading speed on screen of 180 words per minute (WPM)
            const wordsPerSecond = 180 / 60;

            // define total reading time in seconds
            const totalReadingTimeSeconds = totalWords / wordsPerSecond;

            // define reading time
            readingTimeMinutes = Math.floor(totalReadingTimeSeconds / 60);

            // return total reading time in minutes
            if (readingTimeMinutes >= 1) {
                return readingTimeMinutes;
            } else {
                // less than one minute read time
                return '< 1';
            }
        } else {
            return readingTimeMinutes;
        }
    }
}