Omit plugin-proposal-dynamic-import when using preset-env running @babel/cli

[AdamRamberg]

Feature Request

Is your feature request related to a problem? Please describe.
The problem I'm having started after #10109 was released.

I want to use preset-env to transform static ES modules, but not dynamic imports. Dynamic imports should be left untouched. My case is that I'm building shared components / packages that should be transformed before distributed. However, in the consuming applications using the shared packages above I want Webpack to use the dynamic imports for code splitting. I guess that I could omit transforming our shared packages and then transform them in the consuming packages, however I would like to be able to support certain browsers / environments "out of the box" in the the shared packages.

Describe the solution you'd like
Make it possible to send in caller options to the CLI (supportsDynamicImport and supportsStaticESM). Currently the caller option is getting overridden by the CLI, see this. Caller name should still always be overriden by the CLI. Can't think of any drawbacks supporting this behavior.

Describe alternatives you've considered
Another solution would be to support excluding plugin-proposal-dynamic-import via the preset-env config. This however seems a little redundant, since we already have supportsDynamicImport.

Teachability, Documentation, Adoption, Migration Strategy
Usage from command line
babel --caller '{supportsDynamicImport: false}'
Usage in code

const parseArgv = require('@babel/cli/lib/babel/options').default;
const dirCommand = require('@babel/cli/lib/babel/dir').default;
const fileCommand = require('@babel/cli/lib/babel/file').default;

const { babelOptions, cliOptions } = parseArgv(process.argv);

babelOptions.caller = { supportsDynamicImport: false }; // This will now be taken into affect
const babelEntry = cliOptions.outDir ? dirCommand : fileCommand;
const babelResult = await babelEntry({ babelOptions, cliOptions });

[babel-bot]

Hey @AdamRamberg! We really appreciate you taking the time to report an issue. The collaborators
on this project attempt to help as many people as possible, but we're a limited number of volunteers,
so it's possible this won't be addressed swiftly.

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[nicolo-ribaudo]

Doesn't prset-env's exclude option work for your use case?

[AdamRamberg]

@nicolo-ribaudo Nope doesn't work. First of all it throws when it normalizes the options because it checks against this list of plugins, which doesn't contain plugin-proposal-dynamic-import. Secondly, if it was included in the list of plugins it wouldn't work anyways. Both plugin-proposal-dynamic-import and plugin-syntax-dynamic-import are getting special treatment here, and are thereby not affected by the exclude option.

Now when I come back to it, it might be a better solution to just make it possible to exclude plugin-proposal-dynamic-import and plugin-syntax-dynamic-import 🤔 @nicolo-ribaudo Thoughts?

[nicolo-ribaudo]

Yes, I'd consider it a bug that it isn't possible to exclude plugin-proposal-dynamic-import.
Excluding the syntax plugin doesn't make sense instead, since it is what allows Babel to parse it.

[AdamRamberg]

Alright! Makes sense that excluding the syntax plugin isn't desirable.

Haven't been contributing to Babel before, but would like to take a stab at it and create a PR for making it possible to exclude plugin-proposal-dynamic-import. Will take a look at it in the next coming days and submit a PR (if someone else is not beating me to it).

[nicolo-ribaudo]

Thanks! I'm assigning this issue to you, but don't feel pressured 😛

[SebastienGllmt]

I run into the exact same problem where the new version breaks our build and also tried to exclude and it didn't work 😢

[nicolo-ribaudo]

As a workaround, use modules: false and manually include the plugin to transform es modules.

[vivek12345]

@nicolo-ribaudo is this something that I can pick up?

[AdamRamberg]

@vivek12345 the issue has been resolved in #10218, which has been approved by @JLHwung, but has not been merged to master yet. Not sure if something else is needed to get it merged though.

[VivekNayyar]

Alright. I actually missed the PR part. Didn't notice it has a PR already. Thanks for pointing that out.