Support TypeScript with dual CJS/ESM

.gitignore

@@ -2,4 +2,8 @@
 *.log
 node_modules
 package-lock.json
-test.js
+test.js
+.idea/
+dist/
+bun.lock
+.claude/

.npmignore

@@ -1,3 +1,6 @@
 .DS_Store
 *.log
-test.js
+test.js
+src/
+tsconfig.json
+tsup.config.ts

README.md

@@ -15,7 +15,11 @@ npm install randomstring
 ## Usage
 
 ```javascript
-var randomstring = require("randomstring");
+// CommonJS
+const randomstring = require("randomstring");
+
+// ES Modules
+import randomstring from "randomstring";
 
 randomstring.generate();
 // >> "XwPp9xazJ0ku5CZnlmgAx2Dld8SHkAeT"
@@ -46,6 +50,8 @@ randomstring.generate({
 
 ```
 
+TypeScript types are included out of the box — no need to install `@types` separately.
+
 ## API
 
 `randomstring.`
@@ -81,10 +87,11 @@ randomstring.generate({
     $ randomstring length=24 charset=github readable
     > hthbtgiguihgbuttuutubugg
 
-## Tests
+## Development
 
 ```
 npm install
+npm run build
 npm test
 ```
 

bin/randomstring

@@ -1,6 +1,6 @@
 #!/usr/bin/env node
 
-var randomstring = require('..');
+var randomstring = require('../dist/index.js');
 
 var options = {};
 

package.json

@@ -1,26 +1,49 @@
 {
   "name": "randomstring",
-  "version": "1.3.1",
-  "author": "Elias Klughammer <elias@klughammer.com> (http://www.klughammer.com)",
+  "version": "2.0.0",
+  "author": "Elias Klughammer <elias@klughammer.com> (http://www.klughammer.com), Nelie Taylor <nghi@huongda.com> (https://n96.dev)",
   "description": "A module for generating random strings",
   "homepage": "https://github.com/klughammer/node-randomstring",
   "repository": {
     "type": "git",
     "url": "git://github.com/klughammer/node-randomstring.git"
   },
-  "main": "./index",
+  "main": "./dist/index.js",
+  "module": "./dist/index.mjs",
+  "types": "./dist/index.d.ts",
+  "exports": {
+    ".": {
+      "import": {
+        "types": "./dist/index.d.mts",
+        "default": "./dist/index.mjs"
+      },
+      "require": {
+        "types": "./dist/index.d.ts",
+        "default": "./dist/index.js"
+      }
+    }
+  },
   "engines": {
     "node": "*"
   },
+  "files": [
+    "dist",
+    "bin"
+  ],
   "dependencies": {
     "randombytes": "2.1.0"
   },
   "devDependencies": {
-    "mocha": "^10.0.0"
+    "@types/node": "^25.2.3",
+    "mocha": "^11.7.5",
+    "tsup": "^8.4.0",
+    "typescript": "^5.7.0"
   },
   "license": "MIT",
   "scripts": {
-    "test": "mocha"
+    "build": "tsup",
+    "test": "npm run build && mocha",
+    "prepublishOnly": "npm run build"
   },
   "bin": "bin/randomstring"
 }

src/charset.ts

@@ -0,0 +1,69 @@
+export type CharsetType =
+  | 'alphanumeric'
+  | 'numeric'
+  | 'alphabetic'
+  | 'hex'
+  | 'binary'
+  | 'octal'
+  | (string & {});
+
+export class Charset {
+  chars: string;
+
+  constructor() {
+    this.chars = '';
+  }
+
+  setType(type: CharsetType | CharsetType[]): void {
+    if (Array.isArray(type)) {
+      for (let i = 0; i < type.length; i++) {
+        this.chars += this.getCharacters(type[i]);
+      }
+    } else {
+      this.chars = this.getCharacters(type);
+    }
+  }
+
+  getCharacters(type: CharsetType): string {
+    const numbers = '0123456789';
+    const charsLower = 'abcdefghijklmnopqrstuvwxyz';
+    const charsUpper = charsLower.toUpperCase();
+    const hexChars = 'abcdef';
+    const binaryChars = '01';
+    const octalChars = '01234567';
+
+    if (type === 'alphanumeric') {
+      return numbers + charsLower + charsUpper;
+    } else if (type === 'numeric') {
+      return numbers;
+    } else if (type === 'alphabetic') {
+      return charsLower + charsUpper;
+    } else if (type === 'hex') {
+      return numbers + hexChars;
+    } else if (type === 'binary') {
+      return binaryChars;
+    } else if (type === 'octal') {
+      return octalChars;
+    } else {
+      return type;
+    }
+  }
+
+  removeUnreadable(): void {
+    const unreadableChars = /[0OIl]/g;
+    this.chars = this.chars.replace(unreadableChars, '');
+  }
+
+  setcapitalization(capitalization: string): void {
+    if (capitalization === 'uppercase') {
+      this.chars = this.chars.toUpperCase();
+    } else if (capitalization === 'lowercase') {
+      this.chars = this.chars.toLowerCase();
+    }
+  }
+
+  removeDuplicates(): void {
+    const charMap = this.chars.split('');
+    this.chars = [...new Set(charMap)].join('');
+  }
+}