Summary

onUploadProgress crashes with Cannot read property 'loaded' of undefined
on React Native 0.79+ because progressEventReducer reads e.loaded
without guarding the event shape. This adds a defensive check.

Linked issue

Closes #6928

Changes

• lib/helpers/progressEventReducer.js: skip throttled callback when
  the incoming event is missing or loaded is not numeric.
• tests/unit/helpers/progressEventReducer.test.js: cover undefined,
  null, {}, non-numeric loaded, and recovery on a subsequent
  valid event.

Checklist

• Tests added or updated (or N/A with reason)
• Docs / types updated if public API changed (index.d.ts and index.d.cts)
• No breaking changes (or called out explicitly above)

Summary by cubic

Fixes a crash in onUploadProgress on React Native 0.79+ by guarding malformed XHR progress events in progressEventReducer. Prevents "Cannot read property 'loaded' of undefined" and safely ignores invalid events.

Description

• Summary of changes
  • Skip progress callbacks when the event is missing or loaded is not a number.
  • Continue normal processing for the next valid event.
• Reasoning
  • RN 0.79+ can emit undefined/malformed progress events; accessing e.loaded crashed.
• Additional context
  • Closes Axios onUploadProgress error - Cannot read property 'loaded' of undefined #6928.
  • No public API changes; behavior is now defensive under bad events.

Docs

Add a troubleshooting note in /docs/ for React Native uploads: onUploadProgress ignores malformed events to avoid crashes.

Testing

• Added unit tests for undefined, null, {}, and non-numeric loaded.
• Verified no callbacks for malformed events and recovery on a subsequent valid event.

Semantic version impact

• Patch: bug fix with no API or behavior changes for valid inputs.

^{Written for commit b47d238. Summary will update on new commits.}