Bug: Fast Refresh Breaks - unclear why

[Stephen Weiss]

React version: 17.0.2

Steps To Reproduce

1. parcel-bundler/parcel#6974

Link to code example: Have not been able to reproduce reliably.

The current behavior

When I have a custom hook, Parcel seems to choke on Fast Refresh

The expected behavior

Custom hooks work fine.

Additional details

{
  "name": "launcher",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "scripts": {
    "start": "parcel index.html --no-cache --no-hmr",
    "start:mirage": "export MIRAGE=true && yarn run start",
    "build": "parcel build index.html",
    "clean": "rm -rf .parcel-cache dist"
  },
  "dependencies": {
    "lodash": "^4.17.21",
    "miragejs": "^0.1.41",
    "react-app-polyfill": "^1.0.0"
  },
  "alias": {
    "redux-thunk": "../node_modules/redux-thunk",
    "react": "../node_modules/react",
    "react-redux": "../node_modules/react-redux",
    "react-dom": "../node_modules/react-dom/profiling",
    "scheduler/tracing": "../node_modules/scheduler/tracing-profiling"
  },
  "devDependencies": {
    "@parcel/transformer-sass": "2.0.0-beta.2",
    "@types/lodash": "^4.14.170",
    "@types/react": "^16.9.11",
    "@types/react-dom": "^16.8.4",
    "dotenv": "^10.0.0",
    "faker": "^5.5.3",
    "parcel": "^2.0.0-beta.2",
    "typescript": "^3.4.5"
  },
  "volta": {
    "node": "12.22.3"
  }
}

note: My solution was to update the start script to include --no-hmr
There's nothing unique about this config beyond what's set up by TSDX.

[dan]

I don't see a reason to believe this is related to React, since the error is in Parcel. It's up to Parcel to guarantee the globals are defined at an appropriate time.

[Stephen Weiss]

@gaearon - Totally valid response! I wanted to share as much for visibility as anything.

Appreciate you!