Out of the box test coverage is not 100%

I love this as a starting point for React apps, but I am puzzled by one thing…Having Jest and test coverage built in is awesome, but why isn’t coverage 100% out of the box?

If I run the test coverage report, I see:

[Thu Jan 12 11:29:25] fb $ npm test -- --coverage

> fb@0.1.0 test /Users/rob/repos/fb
> react-scripts test --env=jsdom "--coverage"

 PASS  src/App.test.js
  ✓ renders without crashing (18ms)

----------|----------|----------|----------|----------|----------------|
File      |  % Stmts | % Branch |  % Funcs |  % Lines |Uncovered Lines |
----------|----------|----------|----------|----------|----------------|
All files |       50 |      100 |      100 |       50 |                |
 App.js   |      100 |      100 |      100 |      100 |                |
 index.js |        0 |      100 |      100 |        0 |              1 |
----------|----------|----------|----------|----------|----------------|
Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        1.137s
Ran all test suites.

It’d be great to start folks off with 100% tested code - no matter how trivial the index.js file is =)

[wasifhyder]

@TheRobBrennan -

You can exclude index.js from coverage reporting.

I remedied the problem by adding Note: this worked for me on the ejected version of create-react-app. Can’t say for sure how this would behave otherwise

"jest": { "coveragePathIgnorePatterns": ["<rootDir>/src/index.js"] }

https://facebook.github.io/jest/docs/configuration.html#coveragepathignorepatterns-array-string

[thecristen]

I’m experiencing the same issue. I can’t tell if these Jest configs work on an unejected app at all.

edit: However I did have luck adjusting the CLI script. Adding this flag worked for me --collectCoverageFrom='["src/**/*.{js,jsx}", "!src/index.js"]'