Mockito - verify a double value

Question

I have a method called method1 that takes a double which is called on myManager I am passing into this 65.888 * 60. When I try and verify this I get floating point problems. The verification fails. It expects 3953.28 but 3953.280029296875

verify(myManager, times(1)).method1(65.888 * 60d);

Is there anyway I can make this verify do a fuzzy check for floating point checking. Much like you do with assertEquals where you input a delta at the end.

Thanks

Answer 1

You could capture the value, e.g.

final ArgumentCaptor<Double> captor = ArgumentCaptor.forClass(Double.class)
...
verify(myManager).method1(captor.capture());

Then assert:

assertEquals(expected, captor.getValue(), delta)

Or, perhaps, use an argument matcher which does the assertion:

verify(myManager).method1(doubleThat(new ArgumentMatcher<Double>() 
{
    @Override 
    public boolean matches(final Object actual)
    {
        return Math.abs(expected - (Double) actual) <= delta;
    }
}));

Update:

Instead of using either of the methods above, you could use AdditionalMatchers.eq(double, double) instead, e.g.:

verify(myManager).method1(AdditionalMatchers.eq(expected, delta));

Although use AdditonalMatchers matchers wisely, as per the documentation:

AdditionalMatchers provides rarely used matchers, kept only for somewhat compatibility with EasyMock. Use additional matchers very judiciously because they may impact readability of a test. It is recommended to use matchers from Matchers and keep stubbing and verification simple.