`preventAssignment` warning from @rollup/plugin-replace

Current Behavior

I get a warning message from @rollup/plugin-replace when building with tsdx:

@rollup/plugin-replace: 'preventAssignment' currently defaults to false. It is recommended to set this option to `true`, as the next major version will default this option to `true`.

Do not know why I only just started getting this warning message. Any ideas or ways to fix this would be appreciated.

Currently using tsdx in a rush monorepo

[nbgraham]

I’m definitely not an expert, so not sure if there are negative side effects of this, but I was able to remove the warning by adding a tsdx.config.js file at the root level with

// Not transpiled with TypeScript or Babel, so use plain Es6/Node.js!
const replace = require('@rollup/plugin-replace');

module.exports = {
  // This function will run for each entry/format/env combination
  rollup(config, opts) {
    config.plugins = config.plugins.map(p =>
      p.name === 'replace'
        ? replace({
            'process.env.NODE_ENV': JSON.stringify(opts.env),
            preventAssignment: true,
          })
        : p
    );
    return config; // always return a config.
  },
};

I got 'process.env.NODE_ENV': JSON.stringify(opts.env), from this file.

Maybe there should be a PR to add that option in that file? I’m not sure if there could be breaking changes though. preventAssignment documentation

[nandorojo]

Just to be clear, is the code sample above a good solution, or should I ignore the warning? Thanks!