Coverage report not working

[orlandovallejos]

Describe the bug

The problem is that I can't get the coverage report for any project. I used a brand new cra project to test if something is wrong locally but I still have the same problem.
This is what I am supposed to see:

Taken from: https://create-react-app.dev/docs/running-tests/#coverage-reporting

And this is what I see instead:

Did you try recovering your dependencies?

I did.
yarn --version
1.19.1

Environment

Environment Info:

System:
OS: macOS 10.15
CPU: (4) x64 Intel(R) Core(TM) i5-7267U CPU @ 3.10GHz
Binaries:
Node: 12.12.0 - /usr/local/bin/node
Yarn: 1.19.1 - /usr/local/bin/yarn
npm: 6.11.3 - /usr/local/bin/npm
Browsers:
Chrome: 77.0.3865.120
Firefox: 69.0
Safari: 13.0.2
npmPackages:
react: ^16.10.2 => 16.10.2
react-dom: ^16.10.2 => 16.10.2
react-scripts: 3.2.0 => 3.2.0
npmGlobalPackages:
create-react-app: 0.3.0

Steps to reproduce

1. Create a new project using CRA
2. You will see the 3.2.0 version of react-scripts
3. Run npm test -- --coverage or yarn test --coverage

Expected behavior

I should see the coverage report including the App.js file.

Actual behavior

I see no file included in the report:

Reproducible demo

Just used the latest CRA version in an empty project.

[FezVrasta]

I'm hitting the same problem, for now the only workaround I found is to prepend CI=true to yarn test --coverage.

So the working command is CI=true yarn test --coverage --watch

Obviously it has its own downsides.

[stale]

This issue has been automatically marked as stale because it has not had any recent activity. It will be closed in 5 days if no further activity occurs.

[FezVrasta]

Not stale

[yagopv]

If I run it with the watchAll option to false it works

npm test -- --coverage --watchAll=false

[rsliusarchuk-prismhr]

Any workarounds to have watch mode with coverage?

[yagopv]

Mmmm no idea. When I develop I really don't want the application being instrumented and reporting coverage all time so I'm only generating the report when need to check it

[stale]

This issue has been automatically marked as stale because it has not had any recent activity. It will be closed in 5 days if no further activity occurs.

[FezVrasta]

STFU stale bot

[adyz]

Hello,

I have a similar problem, but this time in the generated HTML for the coverage instead.

Here are the steps I've done in order to reproduce this:

• On a fresh install of CRA with typescript (not sure if it matters that much) running npm test -- --coverage --watchAll=false seems to generate a good coverage report and the corresponding HTML in coverage/lcov-report/index.html

• The next test was to eject the CRA running npm run eject and ran the test command above again with success.

• The last step was to remove the node_modules folder and ran npm install.

When the installation was finished I ran once again the test command and in the terminal, the report had all the coverage reported correctly, but the HTML was just showing the percent sign and no actual numbers (see screenshot attached).

Do you think that the issues are related?
I find the HTML much more helpful than the terminal results.

Not sure how to debug this.
I also know that this happens on other projects that are not generated with CRA.

Thank you!