I want to have coverage report for only one file that I am working on at the moment.
It is a bit overwhelming to have the full table of coverage for the whole application files and then search for the one I need.
What I tried was to run test for one file and add --coverage. But it shows coverage for all files:
package.json
...
"test": "react-scripts test",
...
My command
npm test my-component.test --coverage
Is there an option that I can add to this command to show me only my-component.tsx coverage?
The solution is to add one small option --collectCoverageFrom to collect only for a certain file (i.e. component). This is based on this post
NPM version
npm test my-component.test -- --coverage --collectCoverageFrom=src/components/my-component/my-component.tsx
Notice an extra -- before --coverage.... This needs to be passed for npm as following options provided will not be taken into consideration without it.
YARN version
yarn test my-component.test --coverage --collectCoverageFrom=src/components/my-component/my-component.tsx
This will show coverage table only for my-component.tsx.
NOTE:
The path to my-component.tsx file needs to be relative to project root and exact. It cannot be relative as I did for my-component.test.