Empty coverage report when using "type": "module"

Empty coverage report when using "type": "module" in “package.json”.

How to configure everything to work “out of the box”?

Example repo: https://github.com/demo-source/node-app

Here is the output in the original:

Relying on the message: ExperimentalWarning: The ESM module loader is experimental., I assume that the source code is not converted using the module @babel/register, and is still executed as an ESM

But if you manually change the type, but everything works. ("type": "commonjs") if you add a small plug(https://github.com/demo-source/node-app/blob/master/update-package.cjs), and in real-time to replace the type:

[coreyfarrell]

Please see https://github.com/istanbuljs/esm-loader-hook. This provides an experimental method for getting coverage of node.js ES modules in nyc. Keep in mind the node.js api’s it attaches to are still experimental so the loader hook may break upon release of new versions of node.js.

As an alternative to nyc you might check out https://github.com/bcoe/c8. This option uses native v8 functionality for coverage rather than instrumenting code.

[coreyfarrell]

I’m closing this issue as the linked module provides the required support. This is somewhat outside the scope of babel-plugin-istanbul and more within the scope of test runners. Specifically babel-plugin-istanbul does not inject itself into the module loader (CJS or ESM), that is the responsibility of jest, @babel/register, @istanbuljs/esm-loader-hook or other similar loader hooks.