HOW TO: Correctly stub stdout

If you want to stub stdout inside your own code (via process.stdout.write or console.log) the problem is it will effect Mochas reporters, which rely on the same mechanisms to print results of the tests.

i.e.

it('should do, but it do not', function() {
  // user wants to hide output generated by console.log calls in fn 'foo'
  console.log = function() {};
  foo();

  expect(...)
});

This will result in a faulty output.

The correct way to handle this is to stub before and restore after the function call.

it('will do', function() {
  var consoleLogStub = sinon.stub(console, 'log');
  foo();
  consoleLogStub.restore();

  expect(...)
});

Now the reporters can run and print the assertion without any interference, while stubbing stdout inside your function.