Question

I am new to unit testing for web applications
I have a function which creates a connection to a remote mysql database and perform some operations on it .
I want to have a test case which tests the connection is closed or not after the operations on database.
for example
fun1()
{
ODBCConnection con = new ODBCConnection(connString);
con.open();
}
in the above function, the connection is not closed?
how do i check this? can any one help?

Answer 1

In .Net, it’s generally best to open your connections immediately before you use them. So rather than building (and testing) a function that connects to the database, you build and test a function that returns the correct connectionstring. You also have a reference database for your testing environment, and so you build your data access methods and create their own connection and test them against your reference database, that the right results come back.

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Okay, based on your comment I can help you. Since you will be opening and closing the connection in the same function (as you should), you can do this:

public void fun1()
{
    using (ODBCConnection con = new ODBCConnection(connString))
    {
        con.open();
        //use the connection here
    }
    //connection is closed here because of the using block, even if an exception is thrown
}

There is no need to check if the connection closes in the code above. It will be closed in a timely manner by the using block, and that’s guaranteed as much as anything can be in software. Just make sure you use that pattern everywhere you use connections.

In unit testing, the “units” to be tested are methods/functions. You test that the function performs as you expect it to, and nothing more. If you want to test specifically if a connection is closed, than the way to do it is to write a function to close the connection, and test that.