Cannot read property 'map' of undefined in production

[Cody Pearce]

I installed the packages in the README and added gatsby-plugin-react-native-web to gatsbyjs-config. Everything works fine in development, but building the site and serving it in production causes the error below:

"react": "^16.12.0",
"react-dom": "^16.12.0",
"react-native": "^0.62.2",
"react-native-web": "^0.11.7",
"expo": "^37.0.10",
"gatsby": "^2.18.12",
"gatsby-plugin-react-native-web": "^3.1.0",

If I remove the plugin from the config then the issue goes away. I've used V2.0.0 on other Gatsbyjs sites, like https://material-bread.org, without running into this issue. Any ideas what might be wrong?

[Sébastien Lorber]

Hi,

That's unfortunate, I'll have to check that.

Is material bread the repo you are trying to upgrade to v3.1?
Do you have a PR / branch to check?

The config has changed a lot with v3 as we are using the expo webpack config, which does much more than previous version.

[Cody Pearce]

I did some debugging and found disabling gatsby-plugin-offline allows it to work again. I tried to reproduce this behavior in an example repo but couldn't. Sorry, wish I could provide more info but the project is closed source at the moment.

I also found this issue: gatsbyjs/gatsby#10050, which describes the same problem with babel-preset-expo and babel-plugin-react-native-web.

[Sébastien Lorber]

Thanks

Maybe it's related to service workers or something? Can you try with gatsby-plugin-offline but in a private browsing session?

Also, can you try to add this plugin first in the gatsby plugins list? (order may matter, but I don't think it's related here)

[Cody Pearce]

@slorber I was able to reproduce the problem in a stripped down example repo. https://github.com/codypearce/rnw-gatsbyjs-problem

You should be able to see the problem when building the static site and serving it:

npm i
npm run build
npm run serve

[Sébastien Lorber]

thanks, I'll take a look at it probably this weekend or next week