[hacker_9]

That's exactly my point, mock your external dependencies. Static calls don't allow you to do that.

[viraptor]

In your language of choice:

    static_function(db, other, arguments) { ... }
    test { static_function(fake_db, 1, 2) }

You can even omit the db in the standard case if your language allows default keyword arguments. In almost every language, a method is just a fancy static call that takes extra arguments implicitly. (Closures are poor man's objects, objects are poor man's closures...)

[vertex-four]

So how exactly do you test that your SQL query does the right thing? That you're using the Twitter API correctly?

[hacker_9]

Testing a database, or an external web service, is an integration test. They can be as simple as:

    void TestCreateUser() {
        var repo = new UsersRepository();
        var mockUser = new User("John", "Smith");
        repo.AddUser(mockUser); // db call
        var addedUser = repo.GetUsers().Single(); // db call
        Assert.StructureIsEqual(mockUser, addedUser);
    }

For the Twitter web service, you might test that you successfully get a response, as you don't have control of what exactly comes back.