Coverage in HTML view is broken

🐛 Bug Report

To Reproduce

Steps to reproduce the behavior: (same as: https://jestjs.io/docs/en/getting-started)

• Create a new folder
• Init a new npm project with npm init
• Add Jest as a dependency npm install --save-dev jest
• Created a src folder with a main.js file and a main.spec.js test file (one containing sum function and the other the tests as in the Jest docs)
• Added a test script in package.json.
• Run the script with npm test -- --coverage
• When opening the coverage/lcov-report/index.html the HTML does not show the coverage report numbers.

GIT repo here: https://github.com/adyz/jest-coverage-bug-no-ts

Expected behavior

The coverage/lcov-report/index.html should show the actual report numbers

Link to repl or repo (highly encouraged)

https://github.com/adyz/jest-coverage-bug-no-ts

envinfo

npx: installed 1 in 1.36s

  System:
    OS: macOS 10.15.2
    CPU: (16) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
  Binaries:
    Node: 13.6.0 - /usr/local/bin/node
    Yarn: 1.12.3 - ~/.yarn/bin/yarn
    npm: 6.13.4 - /usr/local/bin/npm
  npmPackages:
    jest: ^24.9.0 => 24.9.0 

Let me know if I should send this to the istanbul.js as well or just there. Not sure where to go from here. I’ve also noticed that on old projects the report is fine until I remove the node_modules and reinstall.

Thanks a ton!

[SimenB]

Deleting the existing istanbul-reports from your lockfile and re-running npm or yarn should fix the issue. It works in the project I tested, so I think we’re good to go 👍

[SimenB]

Jest upgraded to istanbul v2 as part of the Jest v24 release (in #7016, to be exact), so upgrading to v24 should fix your issue (as it’ll pull in the fixed version of istanbul-reports@2)