feat: adding failsafe checks to exposed functions

Author: David

README.md

@@ -1,81 +1,103 @@
 # react-native-csrng
+
 High-performance, cross-platform library that provides cryptographically secure random bytes for React Native applications.
 Uses `SecRandomCopyBytes` on iOS and `SecureRandom` on Android.
 
 ## Table of Contents
-- [Usage](#usage)
-- [Installation](#installation)
-- [Example](#example)
-- [Contributing](#contributing)
-- [License](#license)
+
+-   [Usage](#usage)
+-   [Installation](#installation)
+-   [Example](#example)
+-   [Contributing](#contributing)
+-   [License](#license)
 
 ## Usage
+
 The library exports 3 functions:
+
 ### getRandomBytes(length: number) => ArrayBuffer
+
 Takes a length, the number of bytes to generate, and returns an ArrayBuffer with that length of random bytes.
+
 ```javascript
-import { getRandomBytes } from 'react-native-csrng';
+import { getRandomBytes } from 'react-native-csrng'
 
-const randomArrayBuffer = getRandomBytes(12);
+const randomArrayBuffer = getRandomBytes(12)
 ```
 
 ### getRandomInt(min: number, max:number) => number
+
 Takes a min and a max. Returns a random value between those 2 values
+
 ```javascript
-import { getRandomInt } from 'react-native-csrng';
+import { getRandomInt } from 'react-native-csrng'
 
-const randomNumberBetween1And10 = getRandomInt(1, 10);
+const randomNumberBetween1And10 = getRandomInt(1, 10)
 ```
 
 ### generateUUID() => string
+
 Returns a random UUID
+
 ```javascript
-import { getRandomInt } from 'react-native-csrng';
+import { getRandomInt } from 'react-native-csrng'
 
-const randomUUID = generateUUID();
+const randomUUID = generateUUID()
 ```
 
 ## Installation
+
 ```sh
 // Yarn
 yarn add react-native-csrng
 
 // NPM
 npm install react-native-csrng
 ```
+
 ## Example
+
 To run the example, where you can see the library in action you have to run:
+
 1. Install dependencies:
+
     ```sh
     // Yarn
     yarn example install
 
     //NPM
     npm run example install
     ```
+
     1. Install Pods for iOS (only needed for iOS):
         ```sh
         cd example/ios && pod install && cd ../..
         ```
 
 2. Start Metro Bundler:
+
     ```sh
     // Yarn
     yarn example start
 
     // NPM
     npm run example start
     ```
+
 3. Install the app:
+
     1. Android:
+
         ```sh
         // Yarn
         yarn example android
 
         // NPM
         npm run example android
         ```
+
     2. iOS:
+
         ```sh
         // Yarn
         yarn example ios
@@ -91,9 +113,10 @@ Feel free to dive in! [Open an issue](https://github.com/daload/react-native-csr
 react-native-csrng follows the [Contributor Covenant](http://contributor-covenant.org/version/1/3/0/) Code of Conduct.
 
 ### Contributors
-This project exists thanks to all the people who contribute. 
+
+This project exists thanks to all the people who contribute.
 [@Daload](https://github.com/daload)
 
 ## License
 
-[MIT](LICENSE) © Daload
+[MIT](LICENSE) © Daload

src/index.tsx

@@ -3,11 +3,18 @@ import type { Csrng } from './Csrng.nitro'
 
 const CsrngHybridObject = NitroModules.createHybridObject<Csrng>('Csrng')
 
-export function getRandomBytes(n: number): ArrayBuffer {
-	return CsrngHybridObject.getRandomBytes(n)
+export function getRandomBytes(n: number): Uint8Array {
+	if (n < 0) {
+		throw new Error('Number of bytes must be non-negative')
+	}
+	const buffer = CsrngHybridObject.getRandomBytes(n)
+	return new Uint8Array(buffer)
 }
 
 export function getRandomInt(min: number, max: number): number {
+	if (min >= max) {
+		throw new Error('min has to be less than max')
+	}
 	return CsrngHybridObject.getRandomInt(min, max)
 }