fast-replaceall/dist/index.umd.js

Supports global replacement, case-insensitive mode, start index control, and functional replacement compatible with native `String.replace`.

(function(global, factory) {
  typeof exports === "object" && typeof module !== "undefined" ? module.exports = factory() : typeof define === "function" && define.amd ? define(factory) : (global = typeof globalThis !== "undefined" ? globalThis : global || self, global.FastReplaceall = factory());
})(this, function() {
  "use strict";
  function fitIndex(fromIndex, length) {
    return fromIndex ? fromIndex < 0 ? Math.max(0, length + fromIndex) : Math.min(fromIndex, length - 1) : 0;
  }
  function processBlankSegment(str, replacement, isFn, index) {
    return isFn ? replacement("", index, str) : replacement;
  }
  function handleZeroLengthEdgeCase(str, len, replacement, isFn) {
    let result = `${processBlankSegment(str, replacement, isFn, 0)}`;
    for (let i = 0; i < len; i++) {
      result += str[i] + processBlankSegment(str, replacement, isFn, i + 1);
    }
    return result;
  }
  function replaceAll(str, substr, replacement, options) {
    if (typeof str !== "string") {
      return str;
    }
    if (typeof substr !== "string") {
      return str;
    }
    const isFn = typeof replacement === "function";
    const substrLen = substr.length;
    const totalLen = str.length;
    if (substrLen === 0) {
      return handleZeroLengthEdgeCase(str, totalLen, replacement, isFn);
    }
    const { fromIndex, caseInsensitive } = options || {};
    let currentIndex = fitIndex(fromIndex, totalLen);
    let searchStr = substr;
    let sourceStr = str;
    if (caseInsensitive) {
      searchStr = substr.toLowerCase();
      sourceStr = str.toLowerCase();
    }
    let result = "";
    let lastIndex = 0;
    while (currentIndex <= totalLen - substrLen) {
      const matchIndex = sourceStr.indexOf(searchStr, currentIndex);
      if (matchIndex === -1) {
        break;
      }
      result += str.slice(lastIndex, matchIndex);
      if (isFn) {
        result += replacement(
          str.slice(matchIndex, matchIndex + substrLen),
          matchIndex,
          str
        );
      } else {
        result += replacement;
      }
      lastIndex = matchIndex + substrLen;
      currentIndex = lastIndex;
    }
    return lastIndex === 0 ? str : result + str.slice(lastIndex);
  }
  return replaceAll;
});