awesome-string/src/query/ends_with.js

The ultimate JavaScript string library

import clipNumber from 'helper/number/clip_number';
import coerceToString from 'helper/string/coerce_to_string';
import isNil from 'helper/object/is_nil';
import toInteger from 'helper/number/to_integer';

/**
 * Checks whether `subject` ends with `end`.
 *
 * @function endsWith
 * @static
 * @since 1.0.0
 * @memberOf Query
 * @param {string} [subject=''] The string to verify.
 * @param {string} end The ending string.
 * @param {number} [position=subject.length] Search within `subject` as if the string were only `position` long.
 * @return {boolean} Returns `true` if `subject` ends with `end` or `false` otherwise.
 * @example
 * as.endsWith('red alert', 'alert');
 * // => true
 *
 * as.endsWith('metro south', 'metro');
 * // => false
 *
 * as.endsWith('Murphy', 'ph', 5);
 * // => true
 */
export default function endsWith(subject, end, position) {
  if (isNil(end)) {
    return false;
  }
  const subjectString = coerceToString(subject);
  const endString = coerceToString(end);
  if (endString === '') {
    return true;
  }
  position = isNil(position) ? subjectString.length : clipNumber(toInteger(position), 0, subjectString.length);
  position -= endString.length;
  const lastIndex = subjectString.indexOf(endString, position);
  return lastIndex !== -1 && lastIndex === position;
}