Breakpoints are inconsistent after fast refresh (hot reload)

[vzaidman]

Description

Breakpoints are inconsistent after fast refresh (hot reload) and this becomes worse with every hot reload

Steps to reproduce

1. Launch rn-tester
2. Open the debugger from metro with j
3. Fast refresh a few times by updating the code
4. Set some breakpoint

Observe:
It sets many breakpoints for each breakpoint set in unexpected places / breakpoints jump / breakpoints are inconsistent

React Native Version

0.77.0

Screenshots and Videos

Screen.Recording.2025-01-30.at.15.42.39.mov

[react-native-bot]

Warning

Missing reproducer: We could not detect a reproducible example in your issue report. Please provide either:

• If your bug is UI related: a Snack
• If your bug is build/upgrade related: a project using our Reproducer Template
• Otherwise send us a Pull Request with the RNTesterPlayground.js edited to reproduce your bug.

[vzaidman]

Fixed by facebook/metro@cd7a935 in metro v0.81.1.