Rethink / Reconsider / Revamp Babel presets

[paulincai]

Screen generated with a Meteor 3-rc.1 project with meteor npm update:

[denihs]

I tried to reproduce this but I couldn't. Did you do this in an app you migrated to version 3, or was it in an app created with Meteor 3 already?

Do you have the steps for reproduction?

[paulincai]

Hi @denihs this is a project migrated to version 3 through each version since aroudn 2.5. Those notifications are generated by NPM (npm WARN) so I guess the Meteor version is less important.
babel-preset-meteor in the image has the latest version published on NPM which depends on deprecated packages.
https://www.npmjs.com/package/@babel/plugin-proposal-class-properties does have a deprecation notice in NPM like all the other packages in the screenshot.

https://www.npmjs.com/package/@babel/plugin-proposal-class-properties

I think what needs to be done is to implement the more official Babel way which depends on browserlist for the compilation of code. Meteor already offers a way to specify modern vs legacy browsers (the modern-browsers package) so I guess Babel should use those specs for compilation for those with particular needs and use some healthy industry defaults which are not Meteor specific. There are many issues with developers struggling with one version or another being or not being legacy, especially in Cordova.
Example of issues with managing browser versions:

• Meteor legacy browser detection is detecting modern browsers as "legacy". #11670
• https://forums.meteor.com/t/client-architecture-clientarch-web-browser-legacy/54315/5

[henriquealbert]

I can confirm I had the same issue today. @denihs you can ask me how to reproduce it as well