@expo/metro-runtime question

[wataruian]

Hi!

I've setup metro bundler for expo web to replace webpack and it works fine and I can see my app rendered on the browser.

I know that fast refresh does not work. However, on the docs it is mentioned that it is possible (via @expo/metro-runtime) here: https://docs.expo.dev/guides/customizing-metro/#expo-webpack-vs-expo-metro

How can I configure to enable this? I can't find any docs to start with.

Also, how can I inject environment variables for expo web using metro bundler? Cause I conditionally load Storybook or the main app based on the value. I can inject variables using webpack via cross-env RUN_STORYBOOK='true' expo start --web previously but when I changed to metro bundler it does not seem to work?

When I console.log() the value of process.env it only contains NODE_ENV variable. So my main app will always be rendered instead of Storybook regardless of environment variable I set.

I'm not sure if this is the correct repository to post this question but I can see that the @expo/metro-runtime module is inside this repo: https://github.com/expo/router/tree/main/packages/expo-metro-runtime so I decided to post here. 😄

Help is greatly appreciated! Thanks!