Disable coersion of addition of number and string. #4610
This seems like a good idea to me, but it will likely lead to a tough rollout on large codebases. I'm not sure if there would be consensus among the team.
If you are still interested, could you rebase and make sure that tests are passing? If you do, I'll bring this up with other team members to see what they think.
Thanks for the contribution, and sorry for the long wait.
I started a discussion with others on the team about this. While we agree that this is a good idea in principle, we are concerned about the rollout pain (this causes 16,000 new errors in one of our repositories) and the frustration that it could cause users. Of course, the improved safety is a worthwhile goal but we don't think the tradeoff is worth it at this time.
We are interested in making this a Flow lint rule, though. That way it could be configured as a warning or error (or left off altogether) on a per-project basis. I'm not very familiar with how lint rules are implemented but I could spend some time on it if you are interested in reimplementing this as a lint rule.
Feel free to CC me in an issue if you would like implementation guidance.