Monorepo docs issue

[jljorgenson18]

So I just went to hell and back due to a pattern in the v5 docs here.

https://www.nativewind.dev/v5/guides/using-with-monorepos#modify-your-metroconfigjs

const { withNativeWind } = require("nativewind/metro");
 
// ... existing Nx configuration
 
module.exports = withNxMetro(mergeConfig(defaultConfig, customConfig), {
  // ... existing Nx config
}).then((config) => withNativeWind(config));

Basically I was creating an anonymous async function that would call itself and resolve to a config object before. After upgrading, it was like parts of my metro config were being ignored.

I spent a day digging and finally found that metro-config does not actually support promise returns anymore

https://github.com/facebook/metro/blob/main/packages/metro-config/src/loadConfig.js#L240

This did work fine a few versions ago, but exporting a promise now seems to cause an issue where loadConfig internally will skip over the Promise since you end up passing a promise into mergeConfig

 return mergeConfig(defaultConfig, configModule);

I was able to find the issue for it here facebook/metro#1585

Because of that, I think the safer answer for documentation would be to export a function by itself and not export a promise directly.

Example:

module.exports = async () => {
 let config = await withNxMetro(mergeConfig(defaultConfig, customConfig), {
     // ... existing Nx config
 });
 config = withNativeWind(config);
 return config;
}

Metro-config doesn't throw any obvious errors for this as well so it's extra insidious.

[jljorgenson18]

Slight correction, someone did try to fix it but Expo is currently bound to the problematic version. It is still probably safer to settle on a promise

[mikevocalz]

@jljorgenson18 in what metro version is it working?

[jljorgenson18]

This issue is in metro-config@0.83.2 and metro-config@0.83.3

This was the version pinned by expo@54.0.29 as part of their @expo/metro-config package

[mikevocalz]

@jljorgenson18 im goin to try and downgrade to 0.83.1

[danstepanov]

Hey there, thanks for flagging and suggesting a solution. I am actually revisiting the monorepo docs this upcoming weeks and will provide an example to go off in the community resources. I'll link relevant changes to this github issue.

In the meantime, I'll move this issue to our website repo.