fix(insertAt): allow empty string to be inserted

.changeset/few-cups-wash.md

@@ -0,0 +1,5 @@
+---
+"@opentf/utils": minor
+---
+
+Fixed insertAt to allow empty string to be inserted.

README.md

@@ -8,7 +8,7 @@
 
 [![Build](https://github.com/open-tech-foundation/js-utils/actions/workflows/build.yml/badge.svg)](https://github.com/open-tech-foundation/js-utils/actions/workflows/build.yml)
 
-> A Collection of JavaScript Utility Functions.
+> A collection of JavaScript utility functions.
 
 ## [Playground](https://js-utils.pages.dev/playground)
 

apps/website/docs/String/insertAt.mdx

@@ -5,29 +5,34 @@
 ```ts
 import { insertAt } from '@opentf/utils';
 
-insertAt(str: string, index: number, insertStr?: string): string;
+insertAt(str: string, index?: number, insertStr?: string): string;
 ```
 
+:::info
+Default index = 0
+:::
+
+
 ## Examples
 
 ```ts
 insertAt() // It throws an error;
 
-insertAt('')) // ''
+insertAt('') //=> ''
 
-insertAt('', 0)) // ''
+insertAt('', 0) //=> ''
 
-insertAt('', 1, 'abc')) // ''
+insertAt('', 1, 'abc') //=> 'abc'
 
-insertAt('a', 0, 'b')) // 'ba'
+insertAt('a', 0, 'b') //=> 'ba'
 
-insertAt('a', 1, 'b')) // 'ab'
+insertAt('a', 1, 'b') //=> 'ab'
 
-insertAt('a', 1, 'bc')) // 'abc'
+insertAt('a', 1, 'bc') //=> 'abc'
 
-insertAt('foo baz', 3, ' bar')) // 'foo bar baz'
+insertAt('foo baz', 3, ' bar') //=> 'foo bar baz'
 
-insertAt('I want apple', 6, ' an')) // 'I want an apple'
+insertAt('IU', 1, '❤️') //=> 'I❤️U'
 
-insertAt('IU', 1, '❤️')) // 'I❤️U'
+insertAt('I  🍊', 2, 'ate an') //=> 'I ate an 🍊'
 ```

packages/utils/README.md

@@ -8,7 +8,7 @@
 
 [![Build](https://github.com/open-tech-foundation/js-utils/actions/workflows/build.yml/badge.svg)](https://github.com/open-tech-foundation/js-utils/actions/workflows/build.yml)
 
-> A Collection of JavaScript Utility Functions.
+> A collection of JavaScript utility functions.
 
 ## [Playground](https://js-utils.pages.dev/playground)
 

packages/utils/__tests__/string/insertAt.spec.js

@@ -5,12 +5,12 @@ describe('String', () => {
     expect(() => insertAt()).toThrow();
     expect(insertAt('')).toBe('');
     expect(insertAt('', 0)).toBe('');
-    expect(insertAt('', 1, 'abc')).toBe('');
+    expect(insertAt('', 1, 'abc')).toBe('abc');
     expect(insertAt('a', 0, 'b')).toBe('ba');
     expect(insertAt('a', 1, 'b')).toBe('ab');
     expect(insertAt('a', 1, 'bc')).toBe('abc');
     expect(insertAt('foo baz', 3, ' bar')).toBe('foo bar baz');
-    expect(insertAt('I want apple', 6, ' an')).toBe('I want an apple');
+    expect(insertAt('I  🍊', 2, 'ate an')).toBe('I ate an 🍊');
     expect(insertAt('IU', 1, '❤️')).toBe('I❤️U');
   });
 });

packages/utils/package.json

@@ -1,7 +1,7 @@
 {
   "name": "@opentf/utils",
   "version": "0.17.0",
-  "description": "A Collection of JavaScript Utility Functions.",
+  "description": "A collection of JavaScript utility functions.",
   "keywords": [
     "collection",
     "js",

packages/utils/src/string/insertAt.ts

@@ -1,15 +1,5 @@
-function insertAt(str: string, index: number, insertStr = ''): string {
-  if (str.length === 0) {
-    return '';
-  }
-
-  const result = str.substring(0, index) + insertStr + str.substring(index);
-
-  if (typeof index !== 'number') {
-    return str;
-  }
-
-  return result;
+function insertAt(str: string, index = 0, insertStr = ''): string {
+  return str.slice(0, index) + insertStr + str.slice(index);
 }
 
 export default insertAt;