React Daily: Weekly Recap - Server Components & Runtime Compatibility
React's development team focused on critical bug fixes this week, addressing FormData handling issues in Server Components and JavaScript runtime compatibility problems. Three pull requests merged with significant improvements to flight reply processing and error handling.
Duration: PT2M39S
Transcript
Good morning. This is React Daily's weekly recap for May 10th through 17th, 2026.
Three pull requests merged and three additional commits landed this week, concentrating on infrastructure fixes and testing improvements.
Starting with critical fixes: Pull request 36468 from contributor unstubbable resolved a significant regression in React Server Components' FormData handling. The issue occurred in the `decodeReplyFromBusboy` function where FormData entries were being dropped when files and text fields were interleaved in payloads. This particularly affected `useActionState` actions that return submitted FormData as part of their state. The fix replaces the previous tail-flush mechanism with a linked list approach for pending files, ensuring proper order preservation across all server DOM packages including webpack, turbopack, parcel, ESM, and unbundled variants. The change spans 618 lines added and 105 removed across eight files.
Another compatibility fix came from hoxyq in pull request 36455, addressing JavaScript runtime issues with class component constructors. The problem occurred in runtimes without Reflect API support, where React was incorrectly calling constructors without the required `new` keyword, causing TypeErrors in ES6-compliant environments like Hermes. The solution patches class prototypes temporarily during error stack frame generation, maintaining compatibility across different JavaScript runtimes.
For testing infrastructure, jackpope contributed pull request 36467, adding comprehensive unit tests for ViewTransition event callbacks. These tests, extracted from ongoing nested enter/exit work, provide foundational coverage for the ViewTransition API integration with 286 lines of new test code.
All three pull requests received thorough code review with proper approvals before merging. The FormData fix addresses issues linked to Next.js bug reports, indicating real-world impact on production applications.
The additional commits mirror the merged pull requests, with no standalone development work outside the formal review process this week.
Next week, development focus will likely shift toward the ongoing ViewTransition nested behavior work and continued Server Components refinements.
That's your React development update. I'm your host, back next week with more React Daily.