| 'use strict'; |
| |
| var $TypeError = require('es-errors/type'); |
| var isInteger = require('math-intrinsics/isInteger'); |
| var callBound = require('call-bound'); |
| |
| var $slice = callBound('String.prototype.slice'); |
| |
| // https://262.ecma-international.org/12.0/#substring |
| module.exports = function substring(S, inclusiveStart, exclusiveEnd) { |
| if (typeof S !== 'string' || !isInteger(inclusiveStart) || (arguments.length > 2 && !isInteger(exclusiveEnd))) { |
| throw new $TypeError('`S` must be a String, and `inclusiveStart` and `exclusiveEnd` must be integers'); |
| } |
| return $slice(S, inclusiveStart, arguments.length > 2 ? exclusiveEnd : S.length); |
| }; |