How do I test a single file using Jest?

I am able to test multiple files using Jest, but I cannot figure out how to test a single file.

I have:

• Run npm install jest-cli --save-dev
• Updated package.json: `{ … “scripts”: { “test”: “jest” } … }
• Written a number of tests.

Running npm test works as expected (currently it runs 14 tests).

How do I test a single file, e.g. test app/foo/__tests__/bar.spec.js?

I have tried running npm test app/foo/__tests__/bar.spec.js (from the project root), but I get the following error:

npm ERR! Error: ENOENT, open ‘/node_modules/app/foo/tests/bar.spec.js/package.json’