"MetaDataError: CSF missing default export" on *.stories.tsx files which has companion .mdx files

[erik-d]

Describe the bug
Using SB 6.4.9 and feature flag storyStoreV7: true.
In the terminal (running server) I get a lot of info Skipping NoMetaError: CSF: missing default export (line 1, col 0 . These *.stories.tsx files, that gets these NoMetaError, have all a companion mdx file, ex. Button.stories.tsx & Button.stories.mdx.
In this case the .tsx files should not have export default { title: 'Button', ...} according to documentation.

To Reproduce
See description.

System
Environment Info:

System:
OS: macOS 12.0.1
CPU: (8) x64 Intel(R) Core(TM) i7-6820HQ CPU @ 2.70GHz
Binaries:
Node: 14.17.6 - ~/.nvm/versions/node/v14.17.6/bin/node
Yarn: 1.22.15 - ~/.yarn/bin/yarn
npm: 7.24.2 - ~/Work/develop/spx-react-ui/node_modules/.bin/npm
Browsers:
Chrome: 96.0.4664.110
Firefox: 93.0
Safari: 15.1
npmPackages:
@storybook/addon-actions: ^6.4.9 => 6.4.9
@storybook/addon-docs: ^6.4.9 => 6.4.9
@storybook/addon-essentials: ^6.4.9 => 6.4.9
@storybook/addon-interactions: ^6.4.9 => 6.4.9
@storybook/addon-links: ^6.4.9 => 6.4.9
@storybook/addons: ^6.4.9 => 6.4.9
@storybook/core-events: ^6.4.9 => 6.4.9
@storybook/react: ^6.4.9 => 6.4.9
@storybook/testing-library: 0.0.7 => 0.0.7
@storybook/theming: ^6.4.9 => 6.4.9

[micahgodbolt]

Hitting this myself. We have individual files for each story, and then a single top level story file with default export that re-exports the individual stories. The warning is hitting for each of the FooSmall.stories.tsx file that is imported into Foo.stories.tsx.

We could change the extension on FooSmall, but they ARE stories and are linted as such.

[BorisL91]

Any update on this topic? I happen to run into this when integrating the test-runner for interaction testing.

Also using .tsx and .mdx files in our component library.