returnstubtest.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.ReturnStub;
import org.jmock.expectation.AssertMo;
import test.jmock.core.testsupport.MethodFactory;


public class ReturnStubTest
        extends TestCase
{
    static final String RESULT = "result";

    MethodFactory methodFactory;
    Object invokedObject;
    Class invokedObjectClass;
    Invocation invocation;
    ReturnStub returnStub;

    public void setUp() {
        methodFactory = new MethodFactory();

        invokedObject = "INVOKED-OBJECT";
        invokedObjectClass = Void.class;

        returnStub = new ReturnStub(RESULT);
    }

    public void testReturnsValuePassedToConstructor() throws Throwable {
        invocation = new Invocation(invokedObject, methodFactory.newMethodReturning(RESULT.getClass()), null);

        assertSame("Should be the same result object",
                   RESULT, returnStub.invoke(invocation));
    }

    public void testIncludesValueInDescription() {
        StringBuffer buffer = new StringBuffer();

        returnStub.describeTo(buffer);

        String description = buffer.toString();

        assertTrue("contains result in description",
                   description.indexOf(RESULT.toString()) >= 0);
        assertTrue("contains 'returns' in description",
                   description.indexOf("returns") >= 0);
    }

    public void testThrowsAssertionFailedErrorIfTriesToReturnValueOfIncompatibleType()
            throws Throwable {
        invocation = new Invocation(invokedObject, methodFactory.newMethodReturning(int.class), null);

        try {
            returnStub.invoke(invocation);
        }
        catch (AssertionFailedError ex) {
            AssertMo.assertIncludes("expected return type", invocation.invokedMethod.getReturnType().toString(), ex.getMessage());
            AssertMo.assertIncludes("returned value type", RESULT.getClass().toString(), ex.getMessage());
            return;
        }
        fail("should have failed");
    }

    public void testThrowsAssertionFailedErrorIfTriesToReturnValueFromVoidMethod()
            throws Throwable {
        invocation = new Invocation(invokedObject, methodFactory.newMethodReturning(void.class), null);

        try {
            returnStub.invoke(invocation);
        }
        catch (AssertionFailedError ex) {
            AssertMo.assertIncludes("should describe error",
                                    "tried to return a value from a void method", ex.getMessage());
            return;
        }
        fail("should have failed");
    }

    public void testCanReturnNullReference()
            throws Throwable {
        invocation = new Invocation(invokedObject, methodFactory.newMethodReturning(String.class), null);

        returnStub = new ReturnStub(null);

        assertNull("should return null", returnStub.invoke(invocation));
    }

    public void testThrowsAssertionFailedErrorIfTriesToReturnNullFromMethodWithPrimitiveReturnType()
            throws Throwable {
        invocation = new Invocation(invokedObject, methodFactory.newMethodReturning(int.class), null);

        returnStub = new ReturnStub(null);

        try {
            returnStub.invoke(invocation);
        }
        catch (AssertionFailedError ex) {
            AssertMo.assertIncludes("expected return type", invocation.invokedMethod.getReturnType().toString(), ex.getMessage());
            AssertMo.assertIncludes("null", String.valueOf((Object)null), ex.getMessage());
            return;
        }
        fail("should have failed");
    }
}