Unable to resolve "js-base64" from "..." in Expo Web SDK 49

[pachun]

I had an issue in which adding this dependency to a project worked fine as I TDD'd through jest tests but then when I bundled the project for web with metro using yarn web, I received the following in the terminal:

Web Bundling failed 615ms
Unable to resolve "js-base64" from "src/components/MessageIframe/index.tsx"

I found the solution, after some time. I'm posting here only for posterity - or if we feel it's important enough, I will PR the readme.

1. Create a metro config file with npx expo customize metro.config.js as described here
2. Add the line config.resolver.sourceExts.push("mjs") as described here

I know it's not directly the fault of this library, but running into this problem had me lose time trying a bunch of other less well-maintained base64 libraries, before finally coming back to this one and finding a solution for my use case.

Please feel free to close this if it's cluttering issues.