[GROOVY-7608] Comparison of decimal subclasses of Number with == fails

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4.4
• Fix Version/s: 2.5.0-alpha-1
• Component/s: groovy-runtime
• Assignee: Paul King
• Reporter: Sean Gilligan
• Created: 28/Sep/15 08:57
• Updated: 02/May/17 02:03
• Resolved: 26/Jul/16 11:34

Description

If I create a subclass of Number that is implemented internally with a decimal value, e.g. using a BigDecimal even if I implement compareTo(), Groovy will convert my numbers to Integer before comparison.

given:
def one = MyNumberSubclass.of(1)
def oneptone = MyNumberSubclass.of(1.1)

then:
one == onptone          // passes when it shouldn't!
oneptone == oneptone    // fails when it shouldn't!

This is a critical issue for anyone creating a DSL that has custom numeric types (e.g. for currency handling) and wants to compare them with ==.

Specifically this problem occurs with implementations of NumberValue in JSR354 aka JavaMoney.

I can provide some test cases for this if needed and am interesting in working to contribute a fix.

Issue Links

• is related to: GROOVY-7636 NumberMath.getMath suboptimal choice for custom Numbers
• relates to: GROOVY-2756 create new user overwritable operator methods for <,==,>,<=,=>,<==>