util-ex/lib/is/string/regexp.mjs

Browser-friendly enhanced util fully compatible with standard node.js

/**
 * Determines if a string represents a valid JavaScript RegExp.
 * @param {string} aRegExpString - The string to test.
 * @returns {boolean} - True if the string represents a valid EegExp, false otherwise.
 * @example
* isRegExpStr('/[a-z]/g') // true
* isRegExpStr('/not a regexp') // false
*/
export function isRegExpStr(value) {
  let result = typeof value === 'string' && value.length > 2 && value[0] === '/'
  if (result) {
    const i = value.lastIndexOf('/')
    if (i <= 0) {
      result = false
    } else {
      const source = value.slice(1, i)
      const flags = value.slice(i + 1)
      try {
        new RegExp(source, flags)
      } catch (e) {
        result = false
      }
    }
  }
  return result
}
export default isRegExpStr;