Ensuring Code Formatting Consistency in Open Source Contributions

---
description: Enforce consistent code formatting across all source files in open source projects.
globs: ['**/*.js', '**/*.ts', '**/*.jsx', '**/*.tsx', '**/*.py', '**/*.java', '**/*.c', '**/*.cpp', '**/*.cs', '**/*.php', '**/*.rb', '**/*.go']
tags: [code-formatting, open-source, consistency]
priority: 1
version: 1.0.0
---

# Ensuring Code Formatting Consistency in Open Source Contributions

## Context
- Applicable to all source code files in open source projects.
- Ensures uniform code style to enhance readability and maintainability.

## Requirements
- **Indentation**: Use spaces for indentation. The number of spaces per indentation level should be:
  - JavaScript/TypeScript: 2 spaces
  - Python: 4 spaces
  - Java: 4 spaces
  - C/C++: 4 spaces
  - C#: 4 spaces
  - PHP: 4 spaces
  - Ruby: 2 spaces
  - Go: Tabs (equivalent to 8 spaces)
- **Line Length**: Limit lines to a maximum of 80 characters.
- **Trailing Whitespace**: Remove trailing whitespace at the end of lines.
- **Newlines**: Ensure a single newline at the end of each file.
- **Braces Placement**:
  - JavaScript/TypeScript: Opening brace on the same line as the statement.
  - Python: Use indentation to define code blocks; braces are not used.
  - Java: Opening brace on the same line as the statement.
  - C/C++: Opening brace on the same line as the statement.
  - C#: Opening brace on the same line as the statement.
  - PHP: Opening brace on the same line as the statement.
  - Ruby: Use `do...end` for multi-line blocks; braces `{}` for single-line blocks.
  - Go: Opening brace on the same line as the statement.
- **Naming Conventions**:
  - Use descriptive names for variables, functions, and classes.
  - Follow language-specific naming conventions:
    - JavaScript/TypeScript: camelCase for variables and functions; PascalCase for classes.
    - Python: snake_case for variables and functions; PascalCase for classes.
    - Java: camelCase for variables and methods; PascalCase for classes.
    - C/C++: snake_case or camelCase for variables and functions; PascalCase for classes.
    - C#: camelCase for variables and methods; PascalCase for classes.
    - PHP: camelCase for variables and methods; PascalCase for classes.
    - Ruby: snake_case for variables and methods; CamelCase for classes.
    - Go: camelCase for variables and functions; PascalCase for exported names.
- **Comments**:
  - Provide meaningful comments to explain complex logic.
  - Avoid over-commenting; do not explain obvious code.
  - Use language-specific comment styles:
    - JavaScript/TypeScript: `//` for single-line, `/* */` for multi-line.
    - Python: `#` for single-line; triple quotes `"""` for multi-line docstrings.
    - Java: `//` for single-line, `/* */` for multi-line.
    - C/C++: `//` for single-line, `/* */` for multi-line.
    - C#: `//` for single-line, `/* */` for multi-line.
    - PHP: `//` or `#` for single-line, `/* */` for multi-line.
    - Ruby: `#` for single-line; `=begin` and `=end` for multi-line.
    - Go: `//` for single-line, `/* */` for multi-line.
- **Tools**:
  - Utilize code formatters and linters to enforce these standards:
    - JavaScript/TypeScript: [ESLint](https://eslint.org/), [Prettier](https://prettier.io/)
    - Python: [Black](https://black.readthedocs.io/en/stable/), [Flake8](https://flake8.pycqa.org/en/latest/)
    - Java: [Checkstyle](https://checkstyle.org/)
    - C/C++: [ClangFormat](https://clang.llvm.org/docs/ClangFormat.html)
    - C#: [StyleCop](https://github.com/StyleCop/StyleCop)
    - PHP: [PHP_CodeSniffer](https://github.com/squizlabs/PHP_CodeSniffer)
    - Ruby: [RuboCop](https://rubocop.org/)
    - Go: [gofmt](https://golang.org/cmd/gofmt/)

## Examples

// Good: Consistent indentation and brace placement
function calculateTotal(price, tax) {
  const total = price + (price * tax);
  return total;
}
// Bad: Inconsistent indentation and brace placement
function calculateTotal(price, tax)
{
    const total = price + (price * tax);
return total;
}
# Good: Consistent indentation and line length
def calculate_total(price, tax):
    total = price + (price * tax)
    return total
# Bad: Inconsistent indentation and line length
def calculate_total(price, tax):
  total = price + (price * tax)
return total