Application.js

// build/modules/Application.js

module.exports = function() { console.log('hai!'); };

index.js

// test/client/index.js

describe('Application', function() {
    it('should be nice!', function() {
          var Application = require('../../build/modules/Application')
          var app = new Application()
        })
})

package.json

{
  "name": "jefftest",
  "jest": {
    "testDirectoryName": "test",
    "unmockedModulePathPatterns": [
      "<rootDir>/node_modules/react"
    ],
    "testPathIgnorePatterns": [
      "<rootDir>/node_modules"
    ]
  },
  "dependencies": {
    "envify": "^1.2.1",
    "jest-cli": "^0.1.9",
    "react": "^0.10.0"
  }
}

runner output

[jeffmo@jeffmombp.local ~/jtest]$ jest
Found 1 matching tests...
 PASS  test/client/index.js (0.012s)
0/1 tests failed
Run time: 1.363s