check-style

name	check-style
description	Analyze codebase for API consistency, common interface extraction opportunities, and coding style issues. Use when reviewing code quality or before major refactoring.
allowed-tools	Read, Grep, Glob

Coding Style Checker

Analyze this codebase for API consistency and design pattern adherence. Generate a comprehensive report.

Analysis Checklist

1. Backend Interface Consistency

Compare implementations against the interface definition:

Files to examine:

• src/backend.ts - The canonical interface definition
• src/backend-libusb.ts - LibUSB backend implementation
• src/backend-wch.ts - WCH DLL backend implementation

Check for:

• All interface methods are implemented in both backends
• Method signatures match exactly (parameters, return types)
• Error handling follows consistent patterns (same error messages/types)
• Optional methods are handled consistently (throw vs return null)
• Async/await patterns are used consistently

Report any:

• Methods that exist in one backend but not the other
• Different parameter names or types for the same method
• Inconsistent return value shapes
• Platform-specific behavior not documented in the interface

2. Common Interface Extraction

Scan for opportunities to extract shared interfaces:

Files to examine:

• src/types.ts - Central type definitions
• All src/*.ts files - Look for inline type definitions

Check for:

• Duplicate type definitions across files
• Similar structures that could share a base interface
• Inline object types that should be extracted to types.ts
• Generic patterns that could use TypeScript generics

Report any:

• Types defined in multiple places
• Similar types with minor differences (candidates for union/base types)
• Anonymous types in function signatures that repeat

3. Output Format Normalization

Verify backends produce consistent output formats:

Check for:

• Both backends return identical data structures for the same operations
• Numeric values use consistent units (e.g., always bytes, always milliseconds)
• Boolean flags follow same semantics
• Arrays/collections have same ordering guarantees
• Null vs undefined is handled consistently

Report any:

• Platform-specific return value differences
• Different data shapes for logically equivalent operations
• Missing normalization of vendor-specific responses

4. Special Case Containment

Verify platform-specific code is properly encapsulated:

Check for:

• Windows-specific code is contained in WCH backend
• Linux/macOS-specific code is contained in LibUSB backend
• Platform checks don't leak into the main API (index.ts)
• Fallback behaviors are documented

Report any:

• Platform conditionals in the wrong layer
• Implementation details leaking through the facade
• Undocumented behavioral differences between backends

5. API Surface Consistency

Review the public API for consistency:

Files to examine:

• src/index.ts - Main exported API

Check for:

• Method naming follows consistent conventions (camelCase, verb-first)
• Similar operations have similar signatures
• Options objects follow consistent patterns
• Callbacks/promises are used consistently

Report Format

Generate a report with the following sections:

# Coding Style Check Report

## Summary
- Total issues found: X
- Critical (breaks API contract): X
- Warning (inconsistency): X
- Info (improvement opportunity): X

## Critical Issues
[List any issues that could cause runtime errors or break the API contract]

## Warnings
[List inconsistencies that should be addressed]

## Improvement Opportunities
[List suggestions for better interface extraction or normalization]

## Files Analyzed
[List all files examined with line counts]

Specific Patterns for This Codebase

This codebase uses a pluggable backend architecture. Key patterns to verify:

1. CH347Backend interface (backend.ts) defines the contract
2. LibUSBBackend and WCHBackend must implement it identically
3. CH347Device (index.ts) is the facade that delegates to backends
4. Types should be centralized in types.ts

Focus on:

• GPIO operations: gpioRead, gpioWrite, gpioReadAll, gpioPulse, gpioToggle
• SPI operations: spiInit, spiTransfer, spiSendCommand, spiBulkRead
• Flash operations: all methods starting with flash*
• Device lifecycle: open, close, isConnected