[Bug]: Error: Cannot find module '@storybook/experimental-addon-test/internal/coverage-reporter' in monorepo setups

[JReinhold]

In certain monorepo scenarios, Vitest can fail to resolve @storybook/experimental-addon-test/internal/coverage-reporter if it has been hoisted or similar. We are not in control of this resolution, we simply pass in a string to a custom coverage reporter. See docs at:

https://vitest.dev/guide/coverage.html#custom-coverage-reporter

The problem is here on line 45:

storybook/code/addons/test/src/node/vitest-manager.ts

Lines 44 to 50 in 08dca94

	const storybookCoverageReporter: [string, StorybookCoverageReporterOptions] = [
	'@storybook/experimental-addon-test/internal/coverage-reporter',
	{
	testManager: this.testManager,
	coverageOptions: this.vitest?.config?.coverage as ResolvedCoverageOptions<'v8'>,
	},
	];

We could try to use require.resolve (or the ESM equivalent) to get an absolute path at runtime (relative to the current file) instead of referencing the export of our package.

Reproduction

https://github.com/gawdfrey/storybook-experimental-monorepo

1. npm install
2. npm run build
3. npm run dev
4. Go to localhost:6006 and try to run a test with coverage enabled, you should see error in console.

[ndelangen]

We can fix this problem, but the underlaying issue of this repro is the multiple versions of storybook being installed.
(multiple CLI versions, multiple core package versions)

This is causing npm to hoist some packages, and not others.
I've looked at what it's doing, and merging @storybook/core and storybook package would actually help, I think. (though I did not try this, so am not sure it would resolve all)

What I was able to do was hack the node_modules a bit to essentially have the require.resolve around the string.

That solves the issue, and I'm able to run the tests.
I'll open a PR.

But it does feel like this monorepo setup is not in a state, that seems long-term supportable.