---
title: Language-Specific
description: This document outlines the language-specific conventions for the Formbricks codebase, providing guidelines for writing code in TypeScript/JavaScript.
icon: code
---

## TypeScript

Our codebase follows the Vercel Engineering Style Guide conventions.

### ESLint Configuration

We maintain three primary ESLint configurations for different project types:

1. **Library Configuration** (for packages):

```javascript
extends: [
"@vercel/style-guide/eslint/node",
"@vercel/style-guide/eslint/typescript"
]
```


2. **React Configuration** (for React applications):

```javascript
extends: [
"@vercel/style-guide/eslint/node",
"@vercel/style-guide/eslint/typescript",
"@vercel/style-guide/eslint/browser",
"@vercel/style-guide/eslint/react",
"@vercel/style-guide/eslint/next"
]
```


3. **Next.js Configuration** (for Next.js applications):

```javascript
extends: [
"@vercel/style-guide/eslint/node",
"@vercel/style-guide/eslint/typescript",
"@vercel/style-guide/eslint/browser",
"@vercel/style-guide/eslint/react",
"@vercel/style-guide/eslint/next"
]
```


### Key Conventions

1. **TypeScript Usage**
   - Strict TypeScript checking enabled
   - Explicit type annotations when necessary
   - Proper interface and type naming (prefix with T for types, I for interfaces when helpful)
   - No use of `any` type unless absolutely necessary

2. **Imports/Exports**
   - Follow strict import ordering:
     1. Mocks (for testing)
     2. Server-only imports
     3. Third-party modules
     4. Internal `@formbricks/*` modules
     5. Local aliases (`~/*)
     6. Relative imports

3. **Error Handling**
   - Use typed error responses
   - Proper error propagation
   - Consistent error message formatting
   - Implement error boundaries in React components

4. **Async/Await**
   - Prefer async/await over raw promises
   - Proper error handling in async functions
   - Use Promise.all for parallel operations

5. **React Specific**
   - Functional components with TypeScript
   - Proper use of hooks
   - Consistent prop typing
   - Server Components by default in Next.js App Router

### Code Formatting

We use Prettier with specific configurations:

```javascript
{
bracketSpacing: true,
bracketSameLine: true,
singleQuote: false,
jsxSingleQuote: false,
trailingComma: "es5",
semi: true,
printWidth: 110,
arrowParens: "always"
}
```

## Swift
Will be added upon release of the native iOS SDK.

## Kotlin
Will be added upon release of the native Android SDK.