Code Formatting Checker

Instructions

Analyze code files for formatting issues and inconsistencies. Provide a comprehensive report with specific file locations and recommendations.

Step 1: Determine Scope

1. Identify target files:

   • If user specifies files/directories, check those
   • If no target specified, analyze current directory recursively
   • Focus on source code files: .py, .js, .ts, .jsx, .tsx, .rs, .go, .java, .cpp, .c, .h, etc.

2. Use list_directory to explore the codebase structure

3. Use grep_search to find source files by extension

Step 2: Language-Agnostic Formatting Checks

Use grep_search and read_file to check for these common issues:

2.1 Trailing Whitespace

• Pattern: Search for lines ending with spaces or tabs ([ \t]+$)
• Impact: High - causes unnecessary diffs
• Fix: Remove trailing whitespace

2.2 Mixed Line Endings

• Pattern: Check for mixed \r\n (Windows) and \n (Unix)
• Impact: Medium - can cause issues in version control
• Fix: Normalize to one style (prefer \n for Unix)

2.3 Inconsistent Indentation

• Method: Read files and analyze leading whitespace
• Check for:
  • Mix of tabs and spaces
  • Inconsistent indentation levels (2 vs 4 spaces)
  • Files that should be consistent but aren't
• Impact: High - breaks code readability and can cause errors
• Fix: Choose one style per language (Python: 4 spaces, JavaScript: 2 spaces typically)

2.4 File Ending Issues

• Check: Missing newline at end of file (POSIX compliance)
• Check: Extra blank lines at end of file
• Pattern: Read last few lines of files
• Impact: Low-Medium - style consistency
• Fix: Ensure exactly one newline at end of file

2.5 Line Length

• Threshold: Typically 80, 100, or 120 characters (language/project dependent)
• Method: Read files and check line lengths
• Impact: Medium - readability
• Report: List lines exceeding threshold with line numbers

2.6 Blank Line Consistency

• Check: Missing blank lines between functions/classes
• Check: Extra blank lines between sections
• Method: Analyze code structure patterns
• Impact: Low-Medium - style consistency

Step 3: Language-Specific Checks

3.1 Python

• Quotes: Check for inconsistent quote style (single vs double)
• Imports: Check import order and grouping
• Whitespace: PEP 8 spacing around operators, after commas
• Use bash_command: Run black --check or flake8 --select=E,W if available
• Use bash_command: Run ruff check if available (fast Python linter)

3.2 JavaScript/TypeScript

• Quotes: Single vs double quotes consistency
• Semicolons: Consistent use (or lack) of semicolons
• Spacing: Consistent spacing in object literals, function calls
• Use bash_command: Run prettier --check if available
• Use bash_command: Run eslint --fix --dry-run if available

3.3 Rust

• Use bash_command: Run cargo fmt -- --check if available
• Indentation: Standard Rust uses 4 spaces
• Line length: Standard is 100 characters

3.4 Go

• Use bash_command: Run gofmt -l to list files needing formatting
• Use bash_command: Run gofmt -d to show diffs

3.5 General

• Look for project-specific formatters: .prettierrc, .editorconfig, pyproject.toml (with black/flake8 config)
• If formatter config exists, use it for standards

Step 4: Generate Report

Create a comprehensive report with this structure:

# Code Formatting Report

## Summary
- Total files checked: X
- Files with issues: Y
- Critical issues: Z
- Warnings: W

## Issues by Category

### [Category Name]
**Impact**: [High/Medium/Low]
**Count**: [number]

#### Files Affected:
- `path/to/file.ext:line:column` - [description]
- `path/to/file.ext:line:column` - [description]

**Recommendations**:
- [Specific fix instructions]

## Language-Specific Issues

### Python
[Issues found and fixes]

### JavaScript/TypeScript
[Issues found and fixes]

## Suggested Actions

1. [Priority fix]
2. [Next fix]
3. [Optional improvement]

## Formatter Availability

- black: [available/unavailable]
- prettier: [available/unavailable]
- cargo fmt: [available/unavailable]
- gofmt: [available/unavailable]

If formatters are available, suggest running:
```bash
[formatter command]

### Report Format Guidelines

1. **Be specific**: Include file paths, line numbers, and column positions
2. **Prioritize**: Group by impact (Critical, High, Medium, Low)
3. **Actionable**: Provide clear fix instructions
4. **Quantify**: Show counts and statistics
5. **Organize**: Group by issue type and then by file

### Step 5: Provide Fix Suggestions

For each issue type, provide:

1. **Manual fixes**: Exact steps to fix manually
2. **Automated fixes**: Commands to run (if formatters available)
3. **Prevention**: How to avoid in future (editor config, pre-commit hooks)

## Examples

### Example 1: Python Project
User: "Check formatting in this Python project"
- Scan for trailing whitespace
- Check indentation (should be 4 spaces)
- Check line length (PEP 8: 79 chars, but often 100-120 is acceptable)
- Run `black --check` if available
- Report inconsistencies

### Example 2: JavaScript Project
User: "Find formatting issues"
- Check quote consistency
- Check semicolon usage
- Run `prettier --check` if available
- Report all issues with file:line references

### Example 3: Mixed Language Project
User: "Check code style"
- Identify files by extension
- Run language-specific checks
- Use appropriate formatters per language
- Generate unified report

## Best Practices

1. **Check formatter availability first**: Use `bash_command` to test if formatters are installed before suggesting their use
2. **Respect project conventions**: Look for `.editorconfig`, formatter config files
3. **Be thorough but efficient**: Check multiple files in parallel where possible
4. **Prioritize critical issues**: Focus on issues that break functionality (wrong indentation) vs style (quote preference)
5. **Provide context**: Explain why each issue matters

## Tools to Use

- `grep_search`: Find patterns across files (trailing spaces, inconsistent quotes)
- `read_file`: Analyze file contents for indentation, line lengths
- `bash_command`: Run formatters and linters if available
- `list_directory`: Discover project structure and find source files

## Notes

- Some issues are subjective (quote style) - report but note they're style preferences
- Critical issues (wrong indentation) can break code - prioritize these
- Formatters may not be installed - gracefully handle unavailable tools
- Respect existing project style even if it differs from "standard" - consistency within project is key