only-changed-jest-watch-plugin/example/node_modules/which-module/index.js

Jest watch plugin for running either only the modified test (for TDD), or tests of dependant modules

'use strict'

module.exports = function whichModule (exported) {
  for (var i = 0, files = Object.keys(require.cache), mod; i < files.length; i++) {
    mod = require.cache[files[i]]
    if (mod.exports === exported) return mod
  }
  return null
}