Current Behavior

To export umd module, I would like to include all modules into the bundle, so I config the rollup

    if (config.output.format === 'umd') {
      delete config.external;
    }

but when building, it crashes:

(babel plugin) SyntaxError: /Users/bytedance/workspace/ee_web_apps-menu/node_modules/lodash-es/isBuffer.js: 'import' and 'export' may only appe

It may be convenient to expose something to consumers that will make it easier to use Jest - something like the default babel options (presets, plugins, etc.) or a transform module (see something like https://github.com/ActuallyACat/jest-esm-transformer).

This makes using syntax like import/export much easier for folks who use this amazing library for bundling and Jest for tests.

Thank y

does this plugin support in-browser rollup setups?
i can't seem to get it to work (in a client-side setup without node).

in principle, however, rollup supports client-side bundling..

JSPM-mappings is not used by jest. Attempts to import front end dependencies in a test generates an error.

I am currently having a look at jest-jspm as a possible solution.