Istanbul GH-464

index.js

'use strict';

exports.foo = function foo() {
  return 'bar';
};

exports.baz = function baz() {
  return 'qux';
};

package.json

{
  "name": "gh-464",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "coverage": "istanbul cover _mocha",
    "test": "mocha"
  },
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "istanbul": "^0.4.0",
    "mocha": "^2.3.3"
  }
}

test.js

describe('issue', function () {
  'use strict';

  const assert = require('assert');
  const lib = require('./');
  const vm = require('vm');

  const context = vm.createContext({});
  vm.runInContext(lib.baz.toString(), context);

  it('has a `foo` function', function () {
    assert.strictEqual(typeof lib.foo, 'function');
    assert.strictEqual(lib.foo(), 'bar');
  });

  it('has a `baz` function', function () {
    assert.strictEqual(typeof context.baz, 'function');
    assert.strictEqual(context.baz(), 'qux');
  })
});