Enterprise Library Test Guide - Willy .Net

Testing the Data Access Application Block 59
Table 4: Data Access Application Block Code Verification
Code test case Implemented? Feature that is implemented
Verify that the DatabaseProviderFactory
class creates
a new instance of a Database-derived
object for each
request.
Yes
The DatabaseFactory class calls the DatabaseProviderFactory
class, which derives
from the NameTypeFactory base class.
For each request, this class creates a new
instance of a database provider that derives
from the Database class.
Verify that an assembler class
that implements the IDatabaseAssembler
interface
creates the Database-derived
objects and injects the configuration
object values into
those domain objects.
Verify that the application
block uses performance
counters to monitor database
operations when the performance
counters are enabled.
Yes
Yes
The following code demonstrates how the
SqlDatabaseAssembler class, which implements
the IDatabaseAssembler interface,
creates a SQL Server database provider. The
process is similar for Oracle databases and
generic databases.
public class SqlDatabaseAssembler :
IDatabaseAssembler
{
public Database Assemble(string name,
ConnectionStringSettings connection-
StringSettings, IConfigurationSource
configurationSource)
{
return new SqlDatabase(…);
}
}
For example, the Database.OpenConnection
method increments the Connections
Opened/sec performance counter when a database
connection succeeds. This is shown
in the following code example.
protected DbConnection OpenConnection()
{
connection = CreateConnection();
connection.Open();
instrumentationProvider.FireConnectionOpenedEvent();
}
The FireConnectionOpenedEvent method
raises the connectionOpened event. The
ConnectionOpened method consumes this
event and increments the performance
counter. This is shown in the following code
example.
[InstrumentationConsumer("ConnectionO
pened")]
public void ConnectionOpened(…)
{
if (PerformanceCountersEnabled) connectionOpenedCounter.Increment();
}
continued