流类型警告：此模块仅具有默认导出

Question

I have a utils/index.js file which looks something like this to give me quick access to all the utils within my app.

/**
 * @providesModule utils
 * @flow
 */

import isValidEmail from './isValidEmail';
import isWithinVersionRange from './isWithinVersionRange';

...more util functions

export {
  isValidEmail,
  isWithinVersionRange,
}

When I import one of these functions in another file like so...

import { isValidEmail } from 'utils';

Flow throws a warning saying This module only has a default export .

Am I doing something wrong?

Answer 1

I fixed this by changing my flow import to a capital and all references to it to a capital:

/**
 * @providesModule Utils
 * @flow
 */

And then did a find and replace for all 'utils' -> 'Utils'

import { isValidEmail, isWithinVersionRange } from 'Utils';

Then my flow errors were gone and our functions were properly flow typed.

If someone knows why , that'd interesting. But here's the fix.