What is the benefit of prefer-default-export?

The docs don’t have a Why section for prefer-default-export, and I’m not seeing the benefit of it on my own. I would think that not using default is preferred. With default exports, you lose refactoring power (if you rename the source const/function/class, it won’t rename default imports).

As more of an edge case: it makes code less future-proof. i.e. if you create a file that will be a collection of errors, but it only starts with one error, to follow the linting rules, you’ll have to have it export default, but then when you add the 2nd error at a later time, you’ll have to do a bunch of refactoring that could have been prevented if the recommendation was to avoid default export.

[ljharb]

For your edge case: that can totally happen, but that’s the case for an eslint override comment, which is an explicit indicator that this single-export file is intended to be a multiple-export file.

Given that - that you’d basically never have to change a default export to a named export - the refactoring power is all in the filename. Meaning, you a) change the filename and rename all the imports (importjs can do this for you; eslint-plugin-import will ensure you didn’t miss any); b) renaming any of the code in the file does not change how consumers import it; whereas with named exports, the name in the code is tightly coupled to the name that it’s being imported by; c) this rule encourages more files that only ever export one thing, as the default, which is better for readability, maintainability, treeshaking, conceptual understanding, etc.

[ljharb]

@ha404 it’s a ridiculous argument, because you can rename named imports as you bring them in, and you can typo those too. Refactoring is identically easy with default and named exports with respect to the names of the imported variable. Separately, it’s a feature that with default exports, everyone can more easily import it as their own name. If you want consistency with import names in your project, use a linter to enforce that - don’t change your module architecture to try to enforce that, especially when you can’t even force it that way.