EasyMock - matchers are mixed with raw values?

Question

I have this method signature that i want to mock with EasyMock

public BigDecimal getRemainingPremium(BigDecimal baseAmount, Date commencementDate, Date effectiveDate, boolean isComplete)

My test code has

Premium premium = createMock(Premium.class);
// add this line
EasyMock.expect(premium.getCommencementDate()).andReturn(EasyMock.anyObject(Date.class)).anyTimes();
expect(
    premium.getRemainingPremium(
        EasyMock.anyObject(BigDecimal.class),
        EasyMock.anyObject(Date.class),
        EasyMock.anyObject(Date.class),
        EasyMock.anyBoolean()
    ))
    .andReturn(BigDecimal.TEN).anyTimes();

but i keep getting this matcher exception. I've tried all combinations of primitives and 'EasyMock.anyObject(Boolean.class)'. Any suggestions on a workaround?

java.lang.IllegalStateException: 4 matchers expected, 5 recorded.
This exception usually occurs when matchers are mixed with raw values when recording a method:
    foo(5, eq(6));  // wrong
You need to use no matcher at all or a matcher for every single param:
    foo(eq(5), eq(6));  // right
    foo(5, 6);  // also right
    at org.easymock.internal.ExpectedInvocation.createMissingMatchers(ExpectedInvocation.java:48)
    at org.easymock.internal.ExpectedInvocation.<init>(ExpectedInvocation.java:41)
    at org.easymock.internal.RecordState.invoke(RecordState.java:79)
    at org.easymock.internal.MockInvocationHandler.invoke(MockInvocationHandler.java:41)

Answer 1

You're using a matcher where you should to use an actual object.

EasyMock.expect(premium.getCommencementDate()).andReturn(EasyMock.anyObject(Date.class)).anyTimes();

In the line above, you have used the anyObject() matcher where you really mean to use a Date object.

I wonder if you are confusing matchers with mocks in this sense. The anyObject() matcher is a way of confirming that the method you have mocked is called with an object of type Date. It does not create a date object that can be used as an instance of the Date class. For that you would need to create a mock instance of Date. So, keep in mind that matchers should be used as parameters to mocked methods, but not as return values.

The below expectations will fix your issue:

    Date mockDate = EasyMock.createMock(Date.class);
    final IPremium premium = EasyMock.createMock(IPremium.class);
    EasyMock.expect(premium.getCommencementDate()).andReturn(mockDate).anyTimes();
    expect(
            premium.getRemainingPremium(
                    (BigDecimal) EasyMock.anyObject(),
                    (Date) EasyMock.anyObject(),
                    (Date) EasyMock.anyObject(),
                    EasyMock.anyBoolean()
                    ))
                    .andReturn(BigDecimal.TEN).anyTimes();
    replay(premium);