defaultresultstubtest.java

不管是测试驱动开发或者是其它的开发模式

/*  Copyright (c) 2000-2004 jMock.org
 */
package test.jmock.core.stub;

import junit.framework.AssertionFailedError;
import junit.framework.TestCase;
import org.jmock.core.Invocation;
import org.jmock.core.stub.DefaultResultStub;
import org.jmock.expectation.AssertMo;
import test.jmock.core.testsupport.MethodFactory;


public class DefaultResultStubTest extends TestCase {
    static final Object[] NO_ARG_VALUES = new Object[0];

    private static MethodFactory METHOD_FACTORY = new MethodFactory();

    private DefaultResultStub stub;

    public DefaultResultStubTest( String name ) {
        super(name);
    }

    public void setUp() {
        stub = new DefaultResultStub();
    }

    public void testWritesDescritionToStringBuffer() {
        AssertMo.assertIncludes("contains expected description",
                                "returns a default value",
                                stub.describeTo(new StringBuffer()).toString());
    }

    public void testReturnsUsefulDefaultResultsForBasicTypes()
            throws Throwable
    {
        assertHasRegisteredValue(stub, boolean.class, Boolean.FALSE);
        assertHasRegisteredValue(stub, void.class, null);
        assertHasRegisteredValue(stub, byte.class, new Byte((byte)0));
        assertHasRegisteredValue(stub, short.class, new Short((short)0));
        assertHasRegisteredValue(stub, int.class, new Integer(0));
        assertHasRegisteredValue(stub, long.class, new Long(0L));
        assertHasRegisteredValue(stub, char.class, new Character('\0'));
        assertHasRegisteredValue(stub, float.class, new Float(0.0F));
        assertHasRegisteredValue(stub, double.class, new Double(0.0));
        assertHasRegisteredValue(stub, Boolean.class, Boolean.FALSE);
        assertHasRegisteredValue(stub, Byte.class, new Byte((byte)0));
        assertHasRegisteredValue(stub, Short.class, new Short((short)0));
        assertHasRegisteredValue(stub, Integer.class, new Integer(0));
        assertHasRegisteredValue(stub, Long.class, new Long(0L));
        assertHasRegisteredValue(stub, Character.class, new Character('\0'));
        assertHasRegisteredValue(stub, Float.class, new Float(0.0F));
        assertHasRegisteredValue(stub, Double.class, new Double(0.0));
        assertHasRegisteredValue(stub, String.class, "");
    }

    public void testReturnsEmptyArrayForAllArrayTypes()
            throws Throwable
    {
        int[] defaultArrayForPrimitiveType =
                (int[])stub.invoke(invocationReturning(int[].class));
        assertEquals("should be empty array", 0, defaultArrayForPrimitiveType.length);

        Object[] defaultArrayForReferenceType =
                (Object[])stub.invoke(invocationReturning(Object[].class));
        assertEquals("should be empty array", 0, defaultArrayForReferenceType.length);
    }

    public interface InterfaceType {
        int returnInt();
    }

    // Inspired by http://www.c2.com/cgi/wiki?JavaNullProxy
    public void testReturnsProxyOfNewMockObjectWithSameDefaultResultStubForInterfaceTypes()
         throws Throwable
    {
        int intResult = -1;

        stub.addResult(int.class, new Integer(intResult));

        InterfaceType result = (InterfaceType)stub.invoke(invocationReturning(InterfaceType.class));

        assertEquals("int result from 'null' interface implementation",
                     intResult, result.returnInt());
    }

    public void testDefaultResultsCanBeExplicitlyOverriddenByType()
        throws Throwable
    {
        int newDefaultIntResult = 20;
        String newDefaultStringResult = "hello";

        stub.addResult(String.class, newDefaultStringResult);
        stub.addResult(int.class, new Integer(newDefaultIntResult));

        assertEquals("expected registered value for string result type",
                     newDefaultStringResult, stub.invoke(invocationReturning(String.class)));

        assertEquals("expected registered value for int result type",
                     new Integer(newDefaultIntResult), stub.invoke(invocationReturning(int.class)));
    }

    public void testAnExplicitlyRegisteredResultOverridesThePreviousResultForTheSameType()
            throws Throwable
    {
        stub.addResult(String.class, "result1");
        stub.addResult(String.class, "result2");

        assertEquals("expected second result",
                     "result2", stub.invoke(invocationReturning(String.class)));
    }

    class UnsupportedReturnType
    {
    }

    public void testInvocationWithAnUnregisteredReturnTypeCausesAnAssertionFailedError()
            throws Throwable
    {
        Class unsupportedReturnType = UnsupportedReturnType.class;
        Class[] supportedReturnTypes = {
            boolean.class, byte.class, char.class, short.class, int.class, long.class,
            float.class, double.class,
            Boolean.class, Byte.class, Character.class, Short.class, Integer.class, Long.class,
            Float.class, Double.class,
            String.class
        };

        try {
            stub.invoke(invocationReturning(unsupportedReturnType));
        }
        catch (AssertionFailedError ex) {
            String message = ex.getMessage();

            AssertMo.assertIncludes("message should include name of unsupported type",
                                    unsupportedReturnType.getName(), message);

            for (int i = 0; i < supportedReturnTypes.length; i++) {
                AssertMo.assertIncludes("message should include names of expected types",
                                        supportedReturnTypes[i].getName(), message);
            }
            return;
        }

        fail("should have failed");
    }

    public void assertHasRegisteredValue( DefaultResultStub defaultResultStub,
                                          Class resultType,
                                          Object resultValue )
            throws Throwable
    {
        assertEquals("expected " + resultValue + " to be returned",
                     resultValue, defaultResultStub.invoke(invocationReturning(resultType)));
    }

    public void assertHasNotRegisteredReturnType( DefaultResultStub defaultResultStub,
                                                  Class resultType )
            throws Throwable
    {
        try {
            defaultResultStub.invoke(invocationReturning(resultType));
            fail("stub should not support return type " + resultType);
        }
        catch (AssertionFailedError expected) {
            return;
        }
    }

    private Invocation invocationReturning( Class resultType ) {
        return new Invocation("INVOKED-OBJECT",
                              METHOD_FACTORY.newMethodReturning(resultType),
                              NO_ARG_VALUES);
    }
}