test-runner: [Bug] Empty code coverage report

Describe the bug

Hey guys, I’m attempting to setup code-coverage for storybook in my project, I’m able to get everything to run smoothy with yarn test-storybook but when I attempt to use yarn test-storybook --coverage I am getting an empty code coverage report.

I am running against a local storybook build on 6006 as well.

Test Suites: 90 passed, 90 total Tests: 114 passed, 114 total Snapshots: 0 total Time: 86.72 s, estimated 87 s Ran all test suites. Coverage file (2 bytes) written to .nyc_output/coverage.json ----------|---------|----------|---------|---------|-------------------

File	% Stmts	% Branch	% Funcs	% Lines	Uncovered Line #s
All files	0	0	0	0
----------	---------	----------	---------	---------	-------------------
✨ Done in 111.65s.

In addition to that I am seeing that the coverage/storybook/coverage-storybook file has no data, just an empty object.

I have also added the addon-coverage package and updated my .storybook/main.js with @storybook/addon-coverage

I’m wondering if this is a webpack config issue, but I’m not sure what might be the best way to start debugging this.

About this issue

Original URL
State: closed
Created 2 years ago
Reactions: 3
Comments: 17 (6 by maintainers)

Most upvoted comments

Hey everyone, I’ll be closing this issue as it’s not really a bug.

Reason for this to happen:

You are not using @storybook/addon-coverage.
Your project does not use Babel or Vite. Angular, for example. There is a recipe here explaining how to make it work without the addon.
You are using @storybook/addon-coverage however also are manually replacing babel-loader from Storybook to do something custom for your project. This makes it so that the plugin from the addon do not get applied.

If that is not the case and you’re experiencing this exact issue, feel free to reopen this!

yannbf on Nov 16, 2022