@nx/enforce-module-boundaries ESLint Rule

[brannonh]

I am running into an Nx-specific issue where code following the below pattern, established in the vitest module mocking guide, is triggering the @nx/enforce-module-boundaries ESLint rule.

import { expect, vi } from 'vitest'
import { answer } from './example.js'

vi.mock(import('./example.js'), async (importOriginal) => {
  const originalModule = await importOriginal()
  return {
    answer: vi.fn(originalModule.answer),
    variable: 'mock',
  }
})

expect(answer()).toBe(42)

expect(answer).toHaveBeenCalled()
expect(answer).toHaveReturned(42)

The error message from the rule is "Static imports of lazy-loaded libraries are forbidden." It would be triggered in the above example at the import { answer } from './example.js' line, because the same module is lazy-loaded in the vi.mock() call.

I can get around this by adding a bunch of // eslint-disable-next-line @nx/enforce-module-boundaries comments everywhere those modules are statically loaded (including non-spec files), but that is less than ideal.

Has anyone else run into this and/or solved it some other way? I tried editing my eslint.config.js file, but whatever edits I made had no effect.

[AriPerkkio]

The vi.mock(import('./example.js') is just syntax sugar for typescript. You can write the same code without import() as:

- vi.mock(import('./example.js'), async (importOriginal) => {
-  const originalModule = await importOriginal()
+ vi.mock('./example.js', async (importOriginal) => {
+  const originalModule: typeof import('./example.js') = await importOriginal()
  return {
    answer: vi.fn(originalModule.answer),
    variable: 'mock',
  }
})

Though personally I would just disable that ESLint rule from any test files.

[brannonh]

The vi.mock(import('./example.js') is just syntax sugar for typescript. You can write the same code without import() as:

That makes sense. Thanks!

Though personally I would just disable that ESLint rule from any test files.

That's what I was trying to do, but my ESLint config knowledge must be limited. 😆 I'll revisit that option.

[brannonh]

As a follow-up, ignoring test files for that rule doesn't seem to work. Apparently, it still sees both the lazy and static imports and triggers the error from the code files (not the test files).

Switching to the string form did work, though.