Summary

Validates config.timeout early in dispatchRequest before any adapter processes it. Rejects negative, Infinity, and -Infinity values with a clear AxiosError (ERR_BAD_OPTION_VALUE) instead of letting them reach Node.js internals where they cause a confusing RangeError.

Fixes #7428

Motivation

Passing timeout: -1000 crashes with:

RangeError [ERR_OUT_OF_RANGE]: The value of "msecs" is out of range.
    at TLSSocket.setStreamTimeout [as setTimeout] ...

This is confusing because the stack trace points to Node.js internals, not to the axios config. The fix catches this early with:

AxiosError: timeout must be a non-negative number, got `-1000`
    code: 'ERR_BAD_OPTION_VALUE'

Approach

Validation is placed in dispatchRequest.js rather than in individual adapters so that all adapters (http, xhr, fetch) benefit from the check. Non-numeric values (objects, non-numeric strings) are intentionally left to adapter-level handling for backward compatibility (the http adapter uses parseInt to parse string timeouts like '250').

Changes

• lib/core/dispatchRequest.js: Added validateTimeout() that runs before adapter dispatch
• test/unit/core/dispatchRequest.js: 10 new test cases covering negative, Infinity, -Infinity, NaN, zero, null, undefined, positive, string, and negative string timeouts

Test plan

• All 252 existing tests pass (npm run test:node)
• ESLint passes (npm run test:eslint)
• New tests cover all edge cases
• Backward compatible: string timeouts like '250' still work

Summary by cubic

Validates config.timeout in dispatchRequest and rejects negative and infinite values with a clear AxiosError (ERR_BAD_OPTION_VALUE). Prevents confusing Node RangeError and applies consistently across all adapters.

• Bug Fixes

  • Validate timeout before adapter dispatch; reject negative, Infinity, and -Infinity.
  • Keep compatibility: allow numeric strings like '250'; reject negative strings like '-500'.
  • Throw AxiosError with ERR_BAD_OPTION_VALUE and a clear message.
  • Centralized in dispatchRequest so http, xhr, and fetch adapters all benefit.

• Testing

  • Added unit tests for negative, Infinity/-Infinity, NaN, zero, null, undefined, positive, string '250', and negative string '-500'.
  • All existing tests and ESLint pass.

^{Written for commit 4e1d5b1. Summary will update on new commits.}