Angular Sentence Case pipe

sentence-case.pipe.ts

import { Pipe, PipeTransform } from '@angular/core';

/**
 * Pipe to convert a string to sentence case, meaning the first letter of each **sentence** is capitalized.
 *
 * @example
 * {{ 'i am a string. and me too.' | sentenceCase }} => I am a string. And me too.
 *
 * @example
 * {{ 'I AM A STRING. AND ME TOO.' | sentenceCase:true }} => I am a string. And me too.
 *
 * @param value The string to convert to sentence case.
 * @param strict If true, will also convert other characters to lowercase. Use with caution, it will convert all non-alphanumeric characters to lowercase, including acronyms and proper names.
 *
 * @returns The string in sentence case.
 */
@Pipe({
  name: 'sentenceCase',
})
export class SentenceCasePipe implements PipeTransform {
  transform(value: string = '', strict: boolean = false): string {
    if (strict) {
      value = value.toLowerCase();
    }

    return value.replace(
      /(^|\. *)([a-z])/g,
      (match, separator, char) => `${separator}${char.toUpperCase()}`
    );
  }
}