Fix stdio protocol corruption by redirecting console methods to stderr

[Claude]

In stdio transport mode, any output to stdout (console.log, console.warn, etc.) corrupts the MCP JSON-RPC protocol stream, causing immediate client disconnection.

Changes

• src/index.ts: Added redirectConsoleToStderr() function that monkey-patches all console methods to write to stderr when stdio transport is active
• src/services/logger.service.ts: Changed console.warn to console.error for log directory creation failures
• src/stdio-console.test.ts: Added test suite verifying console redirection prevents stdout pollution

Implementation

The fix activates automatically when the server starts in stdio mode:

async function startStdioServer(): Promise<void> {
  // Redirect console to stderr to prevent corruption of the MCP protocol stream
  redirectConsoleToStderr();
  
  const transport = new StdioServerTransport();
  await server.connect(transport);
}

function redirectConsoleToStderr(): void {
  console.log = (...args: unknown[]) => {
    process.stderr.write(`[LOG] ${args.map(String).join(' ')}\n`);
  };
  // ... same for warn, info, debug, error
}

HTTP transport is unaffected as it doesn't use stdio for protocol communication.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Stdio Protocol Corruption via Standard Output</issue_title>
<issue_description>Description: In stdio transport mode, any dependency writing to stdout (e.g., console.log) will corrupt the JSON-RPC stream used by the MCP protocol.

Impact: Immediate disconnection or protocol errors for MCP clients like Claude Desktop.

Recommended Fix: Monkey-patch console.log to redirect to console.error (stderr) when the stdio transport is active.

Affected Files: src/index.ts, src/services/logger.service.ts.</issue_description>

Comments on the Issue (you are @claude[agent] in this section)

• Fixes Stdio Protocol Corruption via Standard Output #27

[codecov]

Codecov Report

❌ Patch coverage is 0% with 13 lines in your changes missing coverage. Please review.
✅ Project coverage is 47.07%. Comparing base (2b24b1d) to head (5e33f13).

Files with missing lines	Patch %	Lines
src/index.ts	0.00%	12 Missing ⚠️
src/services/logger.service.ts	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #28      +/-   ##
==========================================
- Coverage   48.32%   47.07%   -1.26%     
==========================================
  Files          11       11              
  Lines         449      461      +12     
  Branches      103      100       -3     
==========================================
  Hits          217      217              
- Misses        232      244      +12     

Flag	Coverage Δ
unittests	47.07% <0.00%> (-1.26%)	⬇️

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