Question

So I have this unit test:

[TestMethod]
public void TestNullString()
{
    String expectedTestValue = null;
    var uid = Guid.NewGuid().ToString();

    redis.Wait(redis.Strings.Set(db, uid, expectedTestValue));
    var testValue = redis.Wait(redis.Strings.GetString(db, uid));

    Assert.AreEqual(expectedTestValue, testValue);
}

The outcome is a timeout. Is this supposed to happen or am I doing something wrong?

Answer 1

Redis has no concept of null. Either a string is (i.e. "abc" or "" – zero-length strings are fine), or it is not (i.e. the key does not exist).

The “bug” here is that BookSleeve does not check for a null value to .String.Set and throw an exception. That will be rectified imminently.

What is happening currently is that the code is failing when writing the command to the stream – in particular, the redis binary protocol means that you declare the number of arguments before sending the data, i.e. (simplified) “SET”, “2”, “key”, “value” – and since it never writes the value, the server doesn’t even get the chance to send a “that isn’t valid” reply; as far as the server is concerned, it is still waiting for an extra parameter.