Problem

Failed requests can sometimes crash the Node.js process with EPIPE error when the server destroys the socket while the request body is still being written.

This issue was reported in #10558 where the following uncaught exception occurs:

Error: write EPIPE
    at WriteWrap.onWriteComplete [as oncomplete] (node:internal/stream_base_commons:87:19)

Solution

Add an error event handler to the request socket in the HTTP adapter. This catches socket-level errors (like EPIPE, ECONNRESET) that occur after the socket is assigned but might not be caught by the request error handler alone.

Changes

• Added socket error handler in lib/adapters/http.js that rejects the promise with an AxiosError when socket errors occur

Testing

• Verified with reproduction script from Failed requests can sometimes crash the Node.js process with EPIPE. #10558 - the error is now caught and the request properly rejects instead of crashing the process
• All existing HTTP adapter tests pass (132 passed, 2 failed due to unrelated port conflicts in test environment)

Impact

Critical bug fix - Prevents Node.js process crashes in production environments when dealing with unreliable connections or servers that close connections unexpectedly.

Fixes #10558

Summary by cubic

Handle socket errors in the Node.js HTTP adapter to prevent EPIPE/ECONNRESET crashes. Use socket.once to avoid listener leaks on keep‑alive sockets; requests now reject with AxiosError instead of crashing.

Description

• Summary of changes
  • Add socket.once('error', ...) inside req.on('socket', ...) in lib/adapters/http.js
  • On socket error, reject with AxiosError.from(err, null, config, req)
• Reasoning
  • Socket errors after assignment could bypass the request error handler
  • once() prevents listener accumulation on reused keep‑alive sockets
• Additional context
  • Fixes Failed requests can sometimes crash the Node.js process with EPIPE. #10558 and fix(http): handle socket errors to prevent EPIPE crashes #10561
  • Improves stability on unreliable connections

Docs

• No public API changes
• Note: socket errors (e.g., EPIPE, ECONNRESET) surface as AxiosError rejections

Testing

• No new tests
• Manually verified with the Failed requests can sometimes crash the Node.js process with EPIPE. #10558 repro; request rejects and process doesn’t crash
• Recommend regression tests:
  • Server closes socket mid-write → assert rejection with AxiosError carrying code EPIPE/ECONNRESET
  • Keep‑alive reuse → ensure no listener accumulation (e.g., listener count or process warnings)

^{Written for commit c13c943. Summary will update on new commits.}