This repo is a minimal test case for a flow hang bug. To repro, do:
> yarn
yarn install v1.3.2
warning package.json: No license field
warning No license field
[1/4] 🔍 Resolving packages...
success Already up-to-date.
✨ Done in 0.08s.
> node_modules/.bin/flow version
Flow, a static type checker for JavaScript, version 0.66.0
> node_modules/.bin/flow status
Launching Flow server for /Users/akalin/src/flow-hang-bug
Spawned flow server (pid=81350)
Logs will go to /private/tmp/flow/zSUserszSakalinzSsrczSflow-hang-bug.log
Monitor logs will go to /private/tmp/flow/zSUserszSakalinzSsrczSflow-hang-bug.monitor_log
Please wait. Server is initializing (merged files 3/4 (75.0%)): \
<hangs>
Things that cause flow to work again:
- Downgrading flow-bin to 0.65.0.
- Inlining the code in
matrix.jsintorow-reduce.js. - Removing an unused case from the
RowReduceStatetype. - Simplifying
rowReduceNextState.