nist-password-validator/dist/utils/levenshteinDistance.js

A lightweight, zero-dependencies open-source password validator according to NIST guidelines.

"use strict";
var __defProp = Object.defineProperty;
var __getOwnPropDesc = Object.getOwnPropertyDescriptor;
var __getOwnPropNames = Object.getOwnPropertyNames;
var __hasOwnProp = Object.prototype.hasOwnProperty;
var __export = (target, all) => {
  for (var name in all)
    __defProp(target, name, { get: all[name], enumerable: true });
};
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  }
  return to;
};
var __toCommonJS = (mod) => __copyProps(__defProp({}, "__esModule", { value: true }), mod);

// src/utils/levenshteinDistance.ts
var levenshteinDistance_exports = {};
__export(levenshteinDistance_exports, {
  default: () => levenshteinDistance
});
module.exports = __toCommonJS(levenshteinDistance_exports);
function levenshteinDistance(a, b) {
  const normalizeAndSplit = (str) => [...str.normalize("NFC")];
  let aArray = normalizeAndSplit(a);
  let bArray = normalizeAndSplit(b);
  if (aArray.length === 0) return bArray.length;
  if (bArray.length === 0) return aArray.length;
  if (aArray.length < bArray.length) {
    [aArray, bArray] = [bArray, aArray];
  }
  const previousRow = Array.from({ length: bArray.length + 1 }, (_, j) => j);
  const currentRow = new Array(bArray.length + 1);
  for (let i = 1; i <= aArray.length; i++) {
    currentRow[0] = i;
    for (let j = 1; j <= bArray.length; j++) {
      const substitutionCost = aArray[i - 1] === bArray[j - 1] ? 0 : 1;
      currentRow[j] = Math.min(
        previousRow[j] + 1,
        // deletion
        currentRow[j - 1] + 1,
        // insertion
        previousRow[j - 1] + substitutionCost
        // substitution
      );
    }
    for (let j = 0; j <= bArray.length; j++) {
      previousRow[j] = currentRow[j];
    }
  }
  return previousRow[bArray.length];
}