Test

A thorough treatment of testing in the enterprise is beyond the scope of this chapter;

rather, the focus here is on the value add that the adoption of the IoC principle can bring to unit testing;

and on the benefits that the Spring Framework provides in integration testing.

Unit testing

This allows for unit tests to be written in a manner such that the object under test can be simply instantiated with the new operator and have its dependences set in the unit test code.

You can use mock objects (in conjunction with many other valuable testing techniques) to test your code in isolation.

Integration testing

dotnet 最常见两种测试工具： Spring.Testing.NUnit.dll and the MSTest is located in Spring.Testing.Microsoft.dll.

使用起来应该类似。大概看一下。

Context management and caching

文章提到，如果配置文件较多，加载会很慢。为解决这个问题，Spring.net 有如下方案。

In class AbstractDependencyInjectionSpringContextTests has an protected property that subclasses must implement to provide the location of context definition files:

protected abstract string[] ConfigLocations { get; }

In the unlikely case that a test may ‘dirty’ the config location, requiring reloading - for example, by changing an object definition or the state of an application object - you can call the SetDirty() method on AbstractDependencyInjectionSpringContextTests to cause the test fixture to reload the configurations and rebuild the application context before executing the next test case.

Dependency Injection of test fixtures

When AbstractDependencyInjectionSpringContextTests (and subclasses) load your application context, they can optionally configure instances of your test classes by Setter Injection.

All you need to do is to define instance variables and the corresponding setters. AbstractDependencyInjectionSpringContextTests will automatically locate the corresponding object in the set of configuration files specified in the ConfigLocations property.

  • daos.xml

The file referenced by the ConfigLocations method ('classpath:com/foo/daos.xml') looks like this:

<?xml version="1.0" encoding="utf-8" ?>
<objects  xmlns="http://www.springframework.net">

    <!-- this object will be injected into the HibernateTitleDaoTests class -->
    <object id="titleDao" type="Spring.Samples.HibernateTitleDao, Spring.Samples">
        <property name="sessionFactory" ref="sessionFactory"/>
    </object>
    
    <object id="sessionFactory" type="Spring.Data.NHibernate.LocalSessionFactoryObject, Spring.Data.NHibernate">
        <!-- dependencies elided for clarity -->
    </object>

</objects>

一、Using NUnit

[TestFixture]
public class HibernateTitleDaoTests : AbstractDependencyInjectionSpringContextTests  {

    // this instance will be (automatically) dependency injected    
    private HibernateTitleDao titleDao;

    // a setter method to enable DI of the 'titleDao' instance variable
    public HibernateTitleDao HibernateTitleDao {
        set { titleDao = value; }
    }

    [Test]
    public void LoadTitle() {
        Title title = this.titleDao.LoadTitle(10);
        Assert.IsNotNull(title);
    }

    // specifies the Spring configuration to load for this test fixture
    protected override string[] ConfigLocations {
        return new String[] { "assembly://MyAssembly/MyNamespace/daos.xml" };
    }

}

二、Using Microsoft’s Testing Framework

[TestClass]
public class HibernateTitleDaoTests : AbstractDependencyInjectionSpringContextTests  {

    // this instance will be (automatically) dependency injected    
    private HibernateTitleDao titleDao;

    // a setter method to enable DI of the 'titleDao' instance variable
    public HibernateTitleDao HibernateTitleDao {
        set { titleDao = value; }
    }

    [Test]
    public void LoadTitle() {
        Title title = this.titleDao.LoadTitle(10);
        Assert.IsNotNull(title);
    }

    // specifies the Spring configuration to load for this test fixture
    protected override string[] ConfigLocations {
        return new String[] { "assembly://MyAssembly/MyNamespace/daos.xml" };
    }

}

Field level injection

如果由于某种原因，你不想通过 Setter 方法注入，Spring 也可以注入到 protected 的属性上。

[TestFixture]
public class HibernateTitleDaoTests : AbstractDependencyInjectionSpringContextTests {

    public HibernateTitleDaoTests() {
    	   // switch on field level injection
        PopulateProtectedVariables = true;
    }

    // this instance will be (automatically) dependency injected
    protected HibernateTitleDao titleDao;

    [TestMethod]
    public void LoadTitle() {
        Title title = this.titleDao.LoadTitle(10);
        Assert.IsNotNull(title);
    }

    // specifies the Spring configuration to load for this test fixture
    protected override string[] ConfigLocations {
        return new String[] { "assembly://MyAssembly/MyNamespace/daos.xml" };
    }

}

In the case of field injection, there is no autowiring going on: the name of your protected instances variable(s) are used as the lookup object name in the configured Spring container.

Transaction management

这个非常有用。确保所有的数据库测试不会污染数据库。或者是比如测试插入，没有回滚，跑多次就有问题。

AbstractTransactionalDbProviderSpringContextTests 为此而生。

If you want a transaction to commit - unusual, but occasionally useful when you want a particular test to populate the database -

you can call the SetComplete() method inherited from AbstractTransactionalSpringContextTests. This will cause the transaction to commit instead of roll back.

There is also convenient ability to end a transaction before the test case ends, through calling the EndTransaction() method.

This will roll back the transaction by default, and commit it only if SetComplete() had previously been called.

This functionality is useful if you want to test the behavior of ‘disconnected’ data objects,

such as Hibernate-mapped objects that will be used in a web or remoting tier outside a transaction.

Often, lazy loading errors are discovered only through UI testing; if you call EndTransaction() you can ensure correct operation of the UI through your NUnit test suite.