feat: Support Logical Termination on RunQueryResponse

[cherylEnkidu]

Logical Termination: RunQueryResponse will emit "end" event when the "data" event proto which has "done" field set to true.

[schmidt-sebastian]

hasResolved

Also, did you check whether you can just invoke resolve() again?

[schmidt-sebastian]

You should test that you only receive a single 'end' callback. One think you can do is change this to:

let endCounter = 0;
query
        .stream()
        .on('data', doc => {
          expect(doc).to.be.an.instanceOf(DocumentSnapshot);
          ++receivedCounter;
        })
        .on('end', () => {
          expect(received).to.equal(2);
         ++endCounter;
          setImmediate(() => {
             expect(endCounter).to.equal(1);
             callback();
          });
        });
    });
  });

This way, you ensure that once all test processing is done, there is an additional check that verifies that 'end' is only called once. Your test right now does the same thing, but once you call callback test is considered done and it won't fail even if any expectations fail after.