Test suite failed to run

[binomialstew]

This issue introduced to master over the last few days:

 Your test suite must contain at least one test.

      at node_modules/jest-cli/build/test_scheduler.js:157:22

Steps to reproduce

Clone storybook

yarn bootstrap --core && yarn test --core --image

storybook 4.0.0-alpha.2

[Hypnosphi]

You need to run cd examples/official-storybook && yarn build-storybook before image tests. But they actually only test that storyshot image test feature works itself (visual regression testing for our examples is covered better by Chromatic), so you shouldn't need to run it

https://github.com/storybooks/storybook/blob/master/CONTRIBUTING.md#cra-kitchen-sink---image-snapshots-using-storyshots

[binomialstew]

Yes, they all pass after this. Thanks.