ListCompareAlgorithm.AS_SET not working in combination with CustomComparator

[buderjoh]

If you use

JaversBuilder.javers().withListCompareAlgorithm(ListCompareAlgorithm.AS_SET)
.registerCustomComparator(new CustomBigDecimalComparator(2), BigDecimal.class);

The CustomBigDecimalComparator is not invoked.

JaversBuilder.javers().registerCustomComparator(new CustomBigDecimalComparator(2), BigDecimal.class);

is working and CustomBigDecimalComparator is invoked.

    Vehicle v = new Vehicle();
    VehicleCharacteristics c = new VehicleCharacteristics();
    c.setCo2Emission(BigDecimal.valueOf(0));
    v.setCharacteristics(c);

    Vehicle v2 = new Vehicle();
    VehicleCharacteristics c2 = new VehicleCharacteristics();
    c2.setCo2Emission(new BigDecimal("0.00"));
    v2.setCharacteristics(c2);

    Property p2 = ((Building) new Building().setSelf("B111")).setFloors(
            Arrays.asList(new Floor().setArea(BigDecimal.valueOf(3)), new Floor().setArea(BigDecimal.valueOf(7))));
    Property p4 = ((Building) new Building().setSelf("B111")).setFloors(Arrays
            .asList(new Floor().setArea(new BigDecimal("3.00")), new Floor().setArea(new BigDecimal("7.00"))));

    assertFalse(javers.compare(p2, p4))

[bartoszwalacik]

Fixed in 5.7.4

Added possibility to use CustomPropertyComparatortogether with ListCompareAlgorithm.AS_SET. A custom equals() methods is used to compare two Lists without paying attention to ordering and duplicates.

Warning! The list comparing algorithm would be slow in this case for large lists because it has n2 complexity

[buderjoh]

Thanks for fixing this issue.

Unfortunately it is not working in my case with Javers Version 5.7.4

I have my test case attached.
It should work independently so you can try it.

I am using the org.javers.core.diff.custom.CustomBigDecimalComparator.

The testWithSet is not working.
testWithoutSet is working just fine :)

testcase.txt

[bartoszwalacik]

@buderjoh push your code to github as a runnable test case, see https://github.com/javers/javers/blob/master/CONTRIBUTING.md#guidelines-for-bug-reporting

[buderjoh]

The testcase is included in the branch -> https://github.com/buderjoh/javers/tree/javers-832

https://github.com/buderjoh/javers/blob/javers-832/javers-core/src/test/java/org/javers/core/examples/ListCompare.java

Both testcases should work...

The testWithSet is not working.
testWithoutSet works.

[bartoszwalacik]

Your second case is different. Issue happens when you compare List of ValueObjects using AS_SET and one of fields in this ValueObject is a CustomType.

Remember that CustomTypes don't have valid hashCode() so also your ValueObject (Floor) dosn't have a valid hashCode(). Comparing Sets without hashCode() would be very slow for large Sets (n-squared complexity)

[bartoszwalacik]

In 5.8.1, Custom comparators are reinvented, now your case should work. See https://javers.org/release-notes

[buderjoh]

It works thanks :)